Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 37
Filter
1.
ESMO Open ; 9(6): 103488, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38838500

ABSTRACT

BACKGROUND: Fibroblast growth factor receptor 2 (FGFR2) fusions and rearrangements are clinically actionable genomic alterations in cholangiocarcinoma (CCA). Pemigatinib is a selective, potent, oral inhibitor of FGFR1-3 and demonstrated efficacy in patients with previously treated, advanced/metastatic CCA with FGFR2 alterations in FIGHT-202 (NCT02924376). We report final outcomes from the extended follow-up period. PATIENTS AND METHODS: The multicenter, open-label, single-arm, phase II FIGHT-202 study enrolled patients ≥18 years old with previously treated advanced/metastatic CCA with FGFR2 fusions or rearrangements (cohort A), other FGF/FGFR alterations (cohort B), or no FGF/FGFR alterations (cohort C). Patients received once-daily oral pemigatinib 13.5 mg in 21-day cycles (2 weeks on, 1 week off) until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) in cohort A assessed as per RECIST v1.1 by an independent review committee; secondary endpoints included duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety. RESULTS: FIGHT-202 enrolled 147 patients (cohort A, 108; cohort B, 20; cohort C, 17; unconfirmed FGF/FGFR alterations, 2). By final analysis, 145 (98.6%) had discontinued treatment due to progressive disease (71.4%), withdrawal by patient (8.2%), or adverse events (AEs; 6.8%). Median follow-up was 45.4 months. The ORR in cohort A was 37.0% (95% confidence interval 27.9% to 46.9%); complete and partial responses were observed in 3 and 37 patients, respectively. Median DOR was 9.1 (6.0-14.5) months; median PFS and OS were 7.0 (6.1-10.5) months and 17.5 (14.4-22.9) months, respectively. The most common treatment-emergent AEs (TEAEs) were hyperphosphatemia (58.5%), alopecia (49.7%), and diarrhea (47.6%). Overall, 15 (10.2%) patients experienced TEAEs leading to pemigatinib discontinuation; intestinal obstruction and acute kidney injury (n = 2 each) occurred most frequently. CONCLUSIONS: Pemigatinib demonstrated durable response and prolonged OS with manageable AEs in patients with previously treated, advanced/metastatic CCA with FGFR2 alterations in the extended follow-up period of FIGHT-202.


Subject(s)
Bile Duct Neoplasms , Cholangiocarcinoma , Pyrimidines , Humans , Cholangiocarcinoma/drug therapy , Male , Female , Middle Aged , Aged , Adult , Bile Duct Neoplasms/drug therapy , Pyrimidines/therapeutic use , Pyrimidines/pharmacology , Receptor, Fibroblast Growth Factor, Type 2 , Aged, 80 and over , Morpholines , Pyrroles
2.
Lancet ; 402(10409): 1272-1281, 2023 10 07.
Article in English | MEDLINE | ID: mdl-37708904

ABSTRACT

BACKGROUND: Pancreatic ductal adenocarcinoma remains one of the most lethal malignancies, with few treatment options. NAPOLI 3 aimed to compare the efficacy and safety of NALIRIFOX versus nab-paclitaxel and gemcitabine as first-line therapy for metastatic pancreatic ductal adenocarcinoma (mPDAC). METHODS: NAPOLI 3 was a randomised, open-label, phase 3 study conducted at 187 community and academic sites in 18 countries worldwide across Europe, North America, South America, Asia, and Australia. Patients with mPDAC and Eastern Cooperative Oncology Group performance status score 0 or 1 were randomly assigned (1:1) to receive NALIRIFOX (liposomal irinotecan 50 mg/m2, oxaliplatin 60 mg/m2, leucovorin 400 mg/m2, and fluorouracil 2400 mg/m2, administered sequentially as a continuous intravenous infusion over 46 h) on days 1 and 15 of a 28-day cycle or nab-paclitaxel 125 mg/m2 and gemcitabine 1000 mg/m2, administered intravenously, on days 1, 8, and 15 of a 28-day cycle. Balanced block randomisation was stratified by geographical region, performance status, and liver metastases, managed through an interactive web response system. The primary endpoint was overall survival in the intention-to-treat population, evaluated when at least 543 events were observed across the two treatment groups. Safety was evaluated in all patients who received at least one dose of study treatment. This completed trial is registered with ClinicalTrials.gov, NCT04083235. FINDINGS: Between Feb 19, 2020 and Aug 17, 2021, 770 patients were randomly assigned (NALIRIFOX, 383; nab-paclitaxel-gemcitabine, 387; median follow-up 16·1 months [IQR 13·4-19·1]). Median overall survival was 11·1 months (95% CI 10·0-12·1) with NALIRIFOX versus 9·2 months (8·3-10·6) with nab-paclitaxel-gemcitabine (hazard ratio 0·83; 95% CI 0·70-0·99; p=0·036). Grade 3 or higher treatment-emergent adverse events occurred in 322 (87%) of 370 patients receiving NALIRIFOX and 326 (86%) of 379 patients receiving nab-paclitaxel-gemcitabine; treatment-related deaths occurred in six (2%) patients in the NALIRIFOX group and eight (2%) patients in the nab-paclitaxel-gemcitabine group. INTERPRETATION: Our findings support use of the NALIRIFOX regimen as a possible reference regimen for first-line treatment of mPDAC. FUNDING: Ipsen. TRANSLATION: For the plain language summary see Supplementary Materials section.


Subject(s)
Adenocarcinoma , Pancreatic Neoplasms , Humans , Gemcitabine , Paclitaxel , Pancreatic Neoplasms/drug therapy , Pancreatic Neoplasms/pathology , Albumins , Adenocarcinoma/drug therapy , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Pancreatic Neoplasms
3.
Addict Behav ; 113: 106664, 2021 02.
Article in English | MEDLINE | ID: mdl-33038677

ABSTRACT

INTRODUCTION: E-cigarettes are now the most common form of tobacco use among adolescents, and use is associated with increased risk of initiation of cigarette smoking. This project used a community-engaged research process to develop and pilot a risk communication campaign to prevent youth vaping. METHOD: The research team worked with a 36-member Teen Advisory Council and a 19-member Expert Panel. Together, the team employed survey (N = 674) and focus group (N = 82) methodologies, and hired a marketing company to partner on development of the campaign. Campaign concepts were developed, eliminated, and/or modified through an iterative process of feedback and refinement. The final campaign included video ads (https://bit.ly/2QMR8gH) a microsite (rethinkvape.org), and social media sites (@rethinkvape). The campaign communicated three messages to teens: what's in the vapor, health risks, and connections to big tobacco. Prior to launch of the campaign, a randomized controlled 2 (time) × 2 (group) online experiment was conducted to evaluate the campaign (N = 268). RESULTS: Repeated measures mixed analyses of variance indicated that vaping knowledge, perceptions of risk, and anti-vape intentions significantly increased among teens viewing the Rethink Vape Materials compared to their own baseline, while control participants did not change. Following evaluation, the team launched a 6-week online media campaign with a teen-targeted geo-fence radius to deliver 3,838,465 impressions, 770,443 completed video views, and 18,316 clicks in mobile app, Snapchat, YouTube, and Spotify platforms. The majority of placements exceeded industry standards, with mobile pre-roll and Snapchat as top performers. CONCLUSIONS: The e-cigarette campaign showed promising signs of effectiveness and scalability.


Subject(s)
Cigarette Smoking , Electronic Nicotine Delivery Systems , Vaping , Adolescent , Communication , Humans , Marketing
4.
Gastric Cancer ; 21(5): 831-844, 2018 09.
Article in English | MEDLINE | ID: mdl-29397460

ABSTRACT

BACKGROUND: Limited real-world research has investigated ramucirumab for the treatment of patients with gastric or gastroesophageal junction (GEJ) cancer. This study was designed to describe ramucirumab monotherapy or combination therapy use in a community oncology practice setting. METHODS: This was a retrospective observational cohort study to describe the treatment of adult patients with gastric or GEJ cancer who initiated ramucirumab treatment between 4/21/14 and 6/30/16 within the US Oncology Network. Kaplan-Meier method and Cox proportional hazards regression analyses were used to assess clinical outcomes. Multivariable logistic regression models were used to assess patient-level predictors of ramucirumab monotherapy or combination therapy. RESULTS: A total of 505 patients (mean age 64.4 years; 75.1% male) were included in the analysis; subgroups included: monotherapy (22.8%; n = 115), combination therapy (77.2%; n = 390). Monotherapy patients were significantly older (67.7 vs. 63.4 years; P = 0.0006), received ramucirumab approximately 3 months later after diagnosis (16.9 vs. 14.1 months; P = 0.0318) and more frequently initiated ramucirumab in the third or later lines of treatment (38.3 vs. 8.2%; P<0.0001) than patients receiving combination therapy. Median overall survival (OS) for monotherapy and combination therapy from the start of second-line therapy was 5.5 months (confidence interval [CI] 4.3, 7.8) and 7.4 months (CI 6.6, 8.8), respectively. CONCLUSIONS: The results showed that patients who received ramucirumab monotherapy started ramucirumab therapy later after diagnosis and were older than those who received ramucirumab in combination. Additionally, survival data suggest that outcomes observed in community oncology practices are similar to data from phase 3 clinical trials.


Subject(s)
Antibodies, Monoclonal/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Esophageal Neoplasms/drug therapy , Stomach Neoplasms/drug therapy , Adenocarcinoma/drug therapy , Adenocarcinoma/mortality , Aged , Antibodies, Monoclonal/administration & dosage , Antibodies, Monoclonal, Humanized , Esophageal Neoplasms/mortality , Esophageal Neoplasms/pathology , Female , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Retrospective Studies , Stomach Neoplasms/mortality , Stomach Neoplasms/pathology , Treatment Outcome , Ramucirumab
5.
Pancreas ; 47(2): 173-182, 2018 02.
Article in English | MEDLINE | ID: mdl-29206668

ABSTRACT

OBJECTIVE: This study was conducted to understand treatment patterns and clinical outcomes in metastatic gastroenteropancreatic neuroendocrine tumor patients treated in a large community oncology network. METHODS: This retrospective study used the McKesson Specialty Health/US Oncology Network iKnowMed electronic health record database with supplemental chart review. Eligibility criteria included a metastatic neuroendocrine tumor diagnosis between January 1, 2008, and to December 31, 2012; at least 2 US Oncology Network visits; and age at least 18 years. Follow-up was through October 31, 2014. RESULTS: Among the 229 patients identified, median age was 64.0 years, 52.4% were male, 69.4% were white, and 62.9% were overweight/obese. Primary tumor sites included small bowel (47.6%), pancreas (31.4%), and stomach/colorectum (21.0%). There were 16.2% under observation without treatment, 52.4% received only somatostatin analogs (SSAs), and 31.4% received chemotherapy/targeted therapy during treatment. In the first-line setting (n = 192), 77% received SSAs, 12% received chemotherapy, and 10.9% received targeted therapy. Fifty percent of patients receiving octreotide had a relative dose intensity of less than 85%, and 16.7% received above-label dose. Toxicities of SSAs included diarrhea (18.2%), abdominal pain (16.9%), and fatigue (13.5%). Median overall survival from diagnosis was 68.0 months (95% confidence interval, 57.1 to not reached). CONCLUSIONS: Most metastatic gastroenteropancreatic neuroendocrine tumor patients received systemic treatment with SSAs. Patient treatment used an individualized dosing approach. Overall survival and toxicity were consistent with the published literature.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Intestinal Neoplasms/drug therapy , Neuroendocrine Tumors/drug therapy , Pancreatic Neoplasms/drug therapy , Stomach Neoplasms/drug therapy , Adult , Aged , Aged, 80 and over , Female , Humans , Intestinal Neoplasms/pathology , Longitudinal Studies , Male , Middle Aged , Neoplasm Metastasis , Neuroendocrine Tumors/pathology , Pancreatic Neoplasms/pathology , Retrospective Studies , Somatostatin/administration & dosage , Somatostatin/analogs & derivatives , Stomach Neoplasms/pathology , Survival Analysis , United States
6.
Insect Mol Biol ; 25(5): 604-16, 2016 10.
Article in English | MEDLINE | ID: mdl-27286234

ABSTRACT

One of the most striking host range transitions is the evolution of plant parasitism from animal parasitism. Parasitoid wasps that have secondarily evolved to attack plants (ie gall wasps and seed-feeders) demonstrate intimate associations with their hosts, yet the mechanism of plant-host manipulation is currently not known. There is, however, emerging evidence suggesting that ovipositional secretions play a role in plant manipulation. To investigate whether parasites have modified pre-existing adaptations to facilitate dramatic host shifts we aimed to characterize the expression of venom proteins in a plant parasite using a collection of parasitoid venom sequences as a guide. The transcriptome of a seed-feeding wasp, Megastigmus spermotrophus, was assembled de novo and three putative venoms were found to be highly expressed in adult females. One of these putative venoms, aspartylglucosaminidase, has been previously identified as a major venom component in two distantly related parasitoid wasps (Asobara tabida and Leptopilina heterotoma) and may have originated via gene duplication within the Hymenoptera. Our study shows that M. spermotrophus, a specialized plant parasite, expresses putative venom transcripts that share homology to venoms identified in Nasonia vitripennis (both superfamily Chalcidoidea), which suggests that M. spermotrophus may have co-opted pre-existing machinery to develop as a plant parasite.


Subject(s)
Biological Evolution , Transcriptome , Wasp Venoms/genetics , Wasps/physiology , Animals , Gene Expression Profiling , Host Specificity , Phylogeny , Seeds
7.
Oncogene ; 34(6): 671-80, 2015 Feb 05.
Article in English | MEDLINE | ID: mdl-24531711

ABSTRACT

Somatic mutations or deletions of TP53 and PTEN in ductal carcinoma in situ lesions have been implicated in progression to invasive ductal carcinomas. A recent molecular and mutational analysis of breast cancers revealed that inactivation of tumor suppressors, p53 and PTEN, are strongly associated with triple negative breast cancer. In addition, these tumor suppressors have important roles in regulating self-renewal in normal and malignant stem cells. To investigate their role in breast carcinogenesis, we knocked down these genes in human mammary cells and in non-transformed MCF10A cells. p53 and PTEN knockdown synergized to activate pro-inflammatory interleukin-6 (IL6)/Stat3/nuclear factor κB signaling. This resulted in generation of highly metastatic epithelial-to-mesenchymal transition-like cancer stem cells resulting in tumors whose gene expression profile mimicked that found in basal/claudin-low molecular subtype within the triple negative breast tumors. Constitutive activation of this loop in transformed cells was dependent on proteolytic degradation of suppressor of cytokine signaling 3 (SOCS3) resulting in low levels of this protein in basal/claudin-low cell lines and primary tumors. In non-transformed cells, transient activation of the IL6 inflammatory loop induced SOCS3 expression leading to pathway inactivation. In transformed cells, enforced expression of SOCS3 or interfering with IL6 pathway via IL6R blockade inhibited tumor growth and metastasis in mouse xenograft models. Furthermore, circulating tumor cells were significantly reduced in tumor-bearing animals when treated with anti-IL6R antibodies. These studies uncover important connections between inflammation and carcinogenesis and suggest that blocking pro-inflammatory cytokines may be utilized as an attractive strategy to target triple negative breast tumors, which currently lacks molecularly targeted therapies.


Subject(s)
Carcinoma, Intraductal, Noninfiltrating/genetics , PTEN Phosphohydrolase/genetics , Suppressor of Cytokine Signaling Proteins/genetics , Triple Negative Breast Neoplasms/genetics , Tumor Suppressor Protein p53/genetics , Animals , Carcinogenesis , Carcinoma, Intraductal, Noninfiltrating/pathology , Female , Gene Expression Regulation, Neoplastic , Humans , Inflammation/genetics , Inflammation/pathology , Interleukin-6/metabolism , Mice , Receptors, Interleukin-6/metabolism , Suppressor of Cytokine Signaling 3 Protein , Suppressor of Cytokine Signaling Proteins/metabolism , Triple Negative Breast Neoplasms/pathology , Xenograft Model Antitumor Assays
8.
J Natl Compr Canc Netw ; 10(6): 785-93, 2012 Jun 01.
Article in English | MEDLINE | ID: mdl-22679120

ABSTRACT

Carcinoid tumors are relatively indolent, but the treatment of advanced disease remains a challenge. Liver-directed therapies are a consideration in patients with liver-dominant disease. Somatostatin analogs (SSTa) are routinely used to control hormone-mediated symptoms (carcinoid syndrome), but the identification of systemic agents with antitumor efficacy has proven difficult. Aside from octreotide for small bowel carcinoid (which is associated with delayed progression), no treatment has proven antitumor activity. Chemotherapy seems to be of limited value. The role of interferon is also controversial; it is typically used after failure of octreotide. Peptide receptor radionuclide therapy may have activity in patients with SST receptor-expressing tumors, but randomized controlled trials are lacking. Advances in the understanding of the mechanisms underlying tumor progression have led to the identification of several potential therapeutic targets (including the vascular endothelial growth factor [VEGF] and mammalian target of rapamycin [mTOR] signaling pathways), but none has been definitively validated in carcinoid. Everolimus is associated with a trend toward improved progression-free survival in patients with progressive carcinoid, but is not approved for this indication. Therefore, a serious unmet need remains for additional therapeutic strategies for patients with advanced disease. Several avenues are under study, including the use of novel SSTa; VEGF and mTOR inhibitors; and agents that interfere with insulin growth factor 1 receptor and AKT signaling. Moving forward, optimizing patient selection based on clinical features or biomarkers holds promise for identifying individuals most likely to benefit from therapy.


Subject(s)
Carcinoid Tumor/drug therapy , Carcinoid Tumor/pathology , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Humans , Interferons/therapeutic use , Neoplasm Staging , Protein Kinase Inhibitors/therapeutic use , Somatostatin/analogs & derivatives , Somatostatin/therapeutic use , TOR Serine-Threonine Kinases/antagonists & inhibitors , Vascular Endothelial Growth Factor A/antagonists & inhibitors
9.
Food Microbiol ; 30(1): 213-8, 2012 May.
Article in English | MEDLINE | ID: mdl-22265303

ABSTRACT

The aim of this work was to determine the antimicrobial effect of allyl isothiocyanate (AIT) entrapped in alpha and beta cyclodextrin inclusion complexes (ICs). In model experiments, AIT formulations were applied to filter paper discs fixed inside the lid of Petri dishes, where the agar surface was inoculated with the target organism (Penicillium expansum, Escherichia coli or Listeria monocytogenes). Solid phase microextraction coupled with gas chromatography was used to determine static headspace concentrations of AIT formulations. The antimicrobial effect of beta IC was determined during aerobic storage of packaged fresh-cut onions at 5 °C for 20 days. AIT entrapped in beta IC exhibited a significantly (p < 0.05) better antimicrobial effect compared to unentrapped AIT. AIT vapour concentrations in the static system were highest for unentrapped AIT followed by beta IC and alpha IC. Application of beta IC (200 µl/l) to packaged fresh-cut onions effectively decreased numbers of L. monocytogenes, which were also decreased at slower rates to undetectable levels on untreated cut onion. After 10 days, total aerobic counts were ca. 4 log CFU/g lower on onions treated with beta IC (100 and 200 µl/l) compared to untreated controls. This work demonstrates the utility of beta IC as an antimicrobial treatment with potential applications in packaged fresh-cut vegetable products.


Subject(s)
Cyclodextrins/pharmacology , Food Preservation/methods , Food Preservatives/pharmacology , Isothiocyanates/pharmacology , Onions/microbiology , Colony Count, Microbial , Consumer Product Safety , Escherichia coli O157/drug effects , Food Handling/methods , Food Microbiology , Food Packaging/methods , Listeria monocytogenes/drug effects , Vegetables/microbiology
10.
Oncogene ; 27(47): 6120-30, 2008 Oct 16.
Article in English | MEDLINE | ID: mdl-18591932

ABSTRACT

The cancer stem cell hypothesis proposes that cancers arise in stem/progenitor cells through disregulation of self-renewal pathways generating tumors, which are driven by a component of 'tumor-initiating cells' retaining stem cell properties. The HER2 gene is amplified in 20-30% of human breast cancers and has been implicated in mammary tumorigenesis as well as in mediating aggressive tumor growth and metastasis. We demonstrate that HER2 overexpression drives mammary carcinogenesis, tumor growth and invasion through its effects on normal and malignant mammary stem cells. HER2 overexpression in normal mammary epithelial cells (NMEC) increases the proportion of stem/progenitor cells as demonstrated by in vitro mammosphere assays and the expression of stem cell marker aldehyde dehydrogenase (ALDH) as well as by generation of hyperplastic lesions in humanized fat pads of NOD (nucleotide-binding oligomerization domain)/SCID (severe combined immunodeficient) mice. Overexpression of HER2 in a series of breast carcinoma cell lines increases the ALDH-expressing 'cancer stem cell' population which displays increased expression of stem cell regulatory genes, increased invasion in vitro and increased tumorigenesis in NOD/SCID mice. The effects of HER2 overexpression on breast cancer stem cells are blocked by trastuzumab in sensitive, but not resistant, cell lines, an effect mediated by the PI3-kinase/Akt pathway. These studies provide support for the cancer stem cell hypothesis by suggesting that the effects of HER2 amplification on carcinogenesis, tumorigenesis and invasion may be due to its effects on normal and malignant mammary stem/progenitor cells. Furthermore, the clinical efficacy of trastuzumab may relate to its ability to target the cancer stem cell population in HER2-amplified tumors.


Subject(s)
Breast Neoplasms/etiology , Breast/pathology , Neoplastic Stem Cells/cytology , Receptor, ErbB-2/physiology , Aldehyde Dehydrogenase/analysis , Animals , Antibodies, Monoclonal/pharmacology , Antibodies, Monoclonal, Humanized , Breast/cytology , Breast Neoplasms/drug therapy , Breast Neoplasms/pathology , Cell Line, Tumor , Cell Proliferation , Female , Humans , Mice , Mice, Inbred NOD , Mice, SCID , Neoplasm Invasiveness , Neoplastic Stem Cells/drug effects , Phosphatidylinositol 3-Kinases/physiology , Phosphoinositide-3 Kinase Inhibitors , Proto-Oncogene Proteins c-akt/antagonists & inhibitors , Proto-Oncogene Proteins c-akt/physiology , Signal Transduction , Trastuzumab
11.
J Food Sci ; 72(5): E315-9, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17995732

ABSTRACT

Changes to the viscoelastic storage and loss moduli were measured as a function of temperature and oscillatory frequency for 0.5% (w/w) gellan:80% (w/w) cosolute dispersions with added Na(+) (40 to 160 mM). Isothermal frequency (0.15 to 15 Hz) and thermal scans (at 0.15 Hz) were performed over a decreasing then increasing temperature range of 85 to 5 degrees C and 5 to 85 degrees C, respectively. Moduli were found to increase in magnitude with decreasing temperature and increasing levels of Na(+) during cooling, then remained relatively thermally irreversible upon heating. Isothermal frequency (ITF) data were described using the time-temperature superposition (TTS) principle and the modified Cole-Cole (MCC) analysis. Both TTS and the MCC analyses successfully described the behavior of samples containing 40 mM added Na(+) during cooling and heating, and at the 100-mM Na(+) level during cooling. TTS superposed ITF data over the entire temperature range, whereas successful superposition was restricted to lower temperatures in the MCC analysis, where the viscoelastic response was dominated by the long-range relaxation of gellan chains between junction zones. Failure of both analyses was attributed to the formation of junction zones composed of polymer-polymer associations. It is proposed that the addition of Na(+) promotes the formation of a weakly cross-linked gellan network.


Subject(s)
Gels/chemistry , Polysaccharides, Bacterial/chemistry , Sodium/chemistry , Dose-Response Relationship, Drug , Elasticity , Rheology , Sodium/pharmacology , Structure-Activity Relationship , Temperature , Viscosity
12.
Int J Biol Macromol ; 39(4-5): 298-302, 2006 Nov 15.
Article in English | MEDLINE | ID: mdl-16797690

ABSTRACT

The gelling properties (gel time (t(gel)) and gel strength) of a 10% (w/w) gelatin sol were investigated as a function of genipin (GP) concentration (0-15 mM) and temperature (25-55 degrees C) to discern mechanisms and optimal conditions for fixation. Gel time increased with increasing temperature, reached a maximum, and then declined as temperature was raised further. By contrast, network strength data followed the opposite trend. From the thermal behavior of t(gel) and network strength, it was inferred that gelation in the low-temperature regime was dominated by hydrogen bonding, while in the high-temperature regime it was dominated by covalent crosslinking. At higher temperatures, crosslinking was described by an Arrhenius rate law expression, with activation energies between 63.2 and 67.8 kJ/mol, depending on GP concentration. In the low temperature regime, an Arrhenius plot resulted in negative activation energies of -75.8 and -64.4 kJ/mol in the presence of 10 and 15 mM GP, respectively. With an increase in both GP concentration and temperature, the gelatin network gradually shifted from being dominated by hydrogen bonds (physical crosslinks) to covalent crosslinking (chemical crosslinks).


Subject(s)
Gelatin/chemistry , Iridoids/chemistry , Animals , Cross-Linking Reagents , Hydrogels/chemistry , In Vitro Techniques , Iridoid Glycosides , Kinetics , Swine , Thermodynamics
13.
Int J Biol Macromol ; 38(1): 40-4, 2006 Feb 28.
Article in English | MEDLINE | ID: mdl-16443267

ABSTRACT

The physical properties and microstructure of gelatin-maltodextrin hydrogels fixed with genipin (GP) were investigated as a function of pH (3-7), maltodextrin (MD) (0-9%, w/w) and GP (0-10 mM levels), at a constant gelatin (G) concentration (10%, w/w). Network strength (elastic modulus, E) and swelling behavior were characterized by large deformation testing and by swelling index (SI). In general, network strength increased and swelling decreased at higher pH, MD and GP levels, except at pH 3, where E was independent of the GP concentration until approximately 7.5 mM, above which it declined. Confocal scanning laser microscopy (CLSM) images showed phase separation to be suppressed at pH 3, whereas at pH 7, separation into a self-similar dispersed phase was apparent. Overall, the judicious use of GP to crosslink G was an appropriate means of kinetically trapping MD within the gelatin network.


Subject(s)
Gelatin/chemistry , Polysaccharides/chemistry , Pyrans/chemistry , Animals , Chemical Phenomena , Chemistry, Physical , Hydrogels , In Vitro Techniques , Iridoid Glycosides , Iridoids , Microscopy, Confocal , Molecular Structure , Swine
14.
Behav Res Ther ; 44(5): 667-77, 2006 May.
Article in English | MEDLINE | ID: mdl-16002042

ABSTRACT

The current study represents an initial investigation of the association between heroin use and anxiety sensitivity (AS). Within a sample of 172 inner-city treatment seeking drug users, AS was compared across past year (1) heroin users with no crack/cocaine use (n=12); (2) crack/cocaine users with no heroin use (n=66); (3) users of both heroin and crack/cocaine (n=45); and (4) individuals with no use of heroin or crack/cocaine (n=49). Consistent with expectations, primary heroin users evidenced higher levels of AS than all other groups, with these differences also evidenced for the physical and social subscales. Differences in AS total score and physical subscale score persisted after controlling for demographic variables, depressive symptoms, and primary use of drugs other than heroin and crack/cocaine including alcohol, nicotine, marijuana, and hallucinogens. Findings suggest a unique relationship between AS and heroin, and set the stage for future work explicating the direction of the observed association.


Subject(s)
Anxiety/etiology , Heroin Dependence/psychology , Adult , Cocaine-Related Disorders/psychology , Diagnosis, Dual (Psychiatry) , Female , Humans , Male , Middle Aged , Psychiatric Status Rating Scales , Residential Treatment , Urban Health/statistics & numerical data
15.
Cancer Invest ; 22(3): 360-7, 2004.
Article in English | MEDLINE | ID: mdl-15493356

ABSTRACT

PURPOSE: To determine maximum tolerated dose (MTD) and evidence of antitumor activity of topotecan in combination with gemcitabine in refractory cancer patients. METHODS: This was a Phase I, prospective, dose-escalation trial that employed a novel-dosing schema to investigate clinical safety. Patients were treated in six cohorts with topotecan (T)+gemcitabine (G). The doses of T and G were administered by 30-minute IV infusion, T on days one through five (0.3 mg/m2 to 1 mg/m2) and G on days one and 15 of a 28-day cycle (1000 mg/m2 to 1500 mg/m2). Toxicity was monitored. RESULTS: Twenty-three cancer patients were enrolled (colorectal, n=5; lung, n=4; gastric, n=4; esophageal, n=2; other, n=8). Two of three patients developed grade 3 nonhematologic toxicity attributed to study regimen, thereby fulfilling dose limiting toxicity requirements at cohort 6 (T, 1 mg/m2, G, 1500 mg/m2). Maximum tolerated dose (MTD) was established at cohort 5 (T, 1 mg/m2, G, 1250 mg/m2). Ten patients were treated at cohort 5. Nonhematologic adverse effects (AEs) >grade 3 attributed to the study regimen were not observed. Hematologic toxicity was frequent. Twenty-five percent of patients in cohort 2 and 50% of patients in cohorts 4, 5, and 6 had a reduction of ANC to <500 mm3. All neutropenic episodes were less than one week in duration. Five of the patients in the last three cohorts required delay and/or dose-reduction of G. Nineteen of 23 enrolled patients were evaluable for response. Two patients achieved a minimal response. CONCLUSIONS: The MTD was observed at a T dose of 1 mg/m2 administered on days 1 through 15, and a G dose of 1250 mg/m2 administered on days 1 and 15 via 30 minute intravenous (IV) infusion.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Deoxycytidine/analogs & derivatives , Neoplasms/drug therapy , Adult , Aged , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Cohort Studies , Deoxycytidine/administration & dosage , Deoxycytidine/adverse effects , Dose-Response Relationship, Drug , Female , Hematologic Diseases/chemically induced , Humans , Male , Maximum Tolerated Dose , Middle Aged , Prospective Studies , Topotecan/administration & dosage , Topotecan/adverse effects , Treatment Outcome , Gemcitabine
16.
Cancer Gene Ther ; 10(5): 341-52, 2003 May.
Article in English | MEDLINE | ID: mdl-12719704

ABSTRACT

ONYX-015 is an adenovirus that selectively replicates in p53 dysfunctional or mutated malignant cells. We performed a pilot trial to determine the safety and feasibility of treatment with ONYX-015 delivered intravenously in patients with advanced malignancy. One cohort of five patients received ONYX-015 once a week for 6 weeks at a dose of 2 x 10(12) particles per infusion in combination with weekly infusions of irinotecan (CPT11, 125 mg per week) and 5-fluorouracil (5FU, 500 mg per week). A second cohort of five patients received the combination of ONYX-015 at a dose of 2 x 10(11) particles per week for 6 weeks in combination with interleukin 2 (IL 2, 1.1 x 10(6) units daily via subcutaneous injection for 5 days each week for 4 weeks). Toxicity attributable to ONYX-015 was limited to transient fever. All patients demonstrated elevations in neutralizing antibody titers within 4 weeks of the infusion of ONYX-015. Serum levels of IL-6, IL-10, tumor necrosis factor-alpha, and interferon-gamma increased within 6 hours of viral infusion, suggesting immune activation. This response was more pronounced in the cohort of patients who received 2 x 10(12) particles per infusion. Two patients demonstrated uptake of viral particles in malignant tissue by quantitative PCR. Electron microscopy confirmed selective cytoplasmic viral particles within malignant cells but not within adjacent normal tissue in a third patient. In conclusion ONYX-015 can be administered safely in combination with CPT11, 5FU or low-dose IL 2 and is able to access malignant tissue following intravenous infusion. Further investigation of ONYX-015, possibly with agents that may modulate replication activity, or duration of virus survival, is indicated.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Camptothecin/analogs & derivatives , Interleukin-2/therapeutic use , Neoplasms/therapy , Viral Vaccines/therapeutic use , Adenoviridae/genetics , Adenovirus E1B Proteins/genetics , Adenovirus E1B Proteins/metabolism , Adult , Aged , Aged, 80 and over , Camptothecin/administration & dosage , Combined Modality Therapy , Cytokines/blood , Female , Fluorouracil/administration & dosage , Genetic Therapy , Humans , Immunotherapy , Infusions, Intravenous , Irinotecan , Male , Middle Aged , Pilot Projects , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Virus Replication
17.
Med Biol Eng Comput ; 40(4): 380-7, 2002 Jul.
Article in English | MEDLINE | ID: mdl-12227623

ABSTRACT

The object of the paper is to present results that show that impedance spectroscopy is an accurate method of assessing the condition of muscle tissue. Specimens of muscle tissue were excised from 36 Atlantic salmon and subjected to impedance spectroscopy measurements made at intervals during an 8h period of ischaemia and necrosis. These measurements were conducted for three different temperatures and for both the longitudinal and the transverse orientations of the muscle fibres. The specimens were also subjected to ATP, pH and visco-elastic measurement and analysis to establish the degree of correlation between changes in these quantities and impedance spectroscopy parameters due to ischaemia. It was concluded that the mean relaxation time, tau(c) was the impedance spectroscopy parameter that best described the changes taking place in the muscle tissue during the post-mortem period, decreasing by 60-76% during the 8h. This was the case for all three temperatures and for both orientations. Furthermore, the muscle tissue changes due to ischaemia, as reflected in the decrease in the mean relaxation time tau(c), were highly correlated with changes in the tissue ATP, pH and dynamic shear storage modulus G'.


Subject(s)
Electromyography/methods , Infarction/diagnosis , Ischemia/diagnosis , Muscle, Skeletal/blood supply , Animals , Electric Impedance , Salmo salar , Signal Processing, Computer-Assisted
18.
Anal Bioanal Chem ; 372(7-8): 776-85, 2002 Apr.
Article in English | MEDLINE | ID: mdl-12012188

ABSTRACT

The aragonite deposits within the ear bones (otoliths) of teleost fish retain a chemical signal reflecting the life history of fish (similar to rings of trees) and the nature of fish habitats. Otoliths dissolved in acid solutions contain high concentrations of calcium and a variety of proteins. Elimination of matrix salts and organic interferences during preconcentration is essential for accurate determination of trace elements in otolith solutions by inductively coupled plasma-quadrupole mass spectrometry. An iminodiacetate-based chelating resin (Toyopearl AF-Chelate 650 M) has been used for on-line preconcentration and matrix separation for the determination of 31 transition and rare elements. Successful preconcentration of the elements was achieved at pH 5 by on-line buffering, except Mn which required pH 8.8. Sample solutions were loaded on to the column for 1 min at 3.2 mL min(-1), and then eluted directly into the mass spectrometer with 4% v/v nitric acid. This procedure enabled up to 25-fold preconcentration with successful removal of the calcium matrix. The effect of heat-assisted oxidation with concentrated nitric acid was investigated to eliminate the organic matrix. It was found that heating to dryness after dissolution and further mineralization with the acid significantly improved the retention of the transition elements. The method was validated by analysis of a certified reference material produced from saggittal otoliths of emperor snapper ( Lutjanus sebae), and then applied to the determination of trace metal concentrations in juvenile bluefin tuna ( Thunnus thynnus) from the Western Pacific Ocean.


Subject(s)
Carbonates/analysis , Mass Spectrometry/methods , Otolithic Membrane/chemistry , Perciformes , Animals , Calibration , Hot Temperature , Isotopes , Mass Spectrometry/instrumentation , Nitric Acid , Reproducibility of Results , Sensitivity and Specificity , Software
19.
Biophys Chem ; 94(1-2): 47-58, 2001 Dec 11.
Article in English | MEDLINE | ID: mdl-11744190

ABSTRACT

This study examined the flocculation behavior of two Saccharomyces cerevisiae strains expressing either Flo1 (LCC1209) genotype or NewFlo (LCC125) phenotype in a laminar flow field by measurement of the fundamental flocculation parameter, the orthokinetic capture coefficient. This orthokinetic capture coefficient was measured as a function of shear rate (5.95-223 s(-1)) and temperature (5-45 degrees C). The capture coefficients of these suspensions were directly proportional to the inverse of shear rate, and exhibited an increase as the temperature was increased to 45 degrees C. The capture coefficient of pronase-treated cells was also measured over similar shear rate and temperature range. A theory, which predicts capture coefficient values due to zymolectin interactions, was simplified from that developed by Long et al. [Biophys. J. 76: (1999) 1112]. This new modified theory uses estimates of: (1) cell wall densities of zymolectins and carbohydrate ligands; (2) cell wall collision contact area; and (3) the forward rate coefficient of binding to predict theoretical capture coefficients. A second model that involves both zymolectin interactions and DLVO forces was used to describe the phenomenon of yeast flocculation at intermediate shear ranges, to explain yeast flocculation in laminar flow.


Subject(s)
Saccharomyces cerevisiae/physiology , Antigen-Antibody Reactions , Flocculation , Kinetics , Pronase/metabolism , Temperature
20.
Sci Total Environ ; 278(1-3): 31-44, 2001 Oct 20.
Article in English | MEDLINE | ID: mdl-11669275

ABSTRACT

The conservative biogeochemical behavior of dissolved Zn and Cd in a 17-km, free-flowing reach of the Coeur d'Alene River downstream of a mining district is typical of watersheds in which suspended matter concentrations are low. For watersheds impacted by acid-rock drainage (ARD), low suspended matter concentrations are more likely to be found when acid rock drainage travels through soils because much of the Fe and Al that could form adsorbing surfaces is retained within the soils. In the absence of additional sources of solid substrates, metals can be transported great distances downstream once this Fe- and Al-poor ARD seeps into surface waters. In a 46-km backwater reach of the Coeur d'Alene River, it appears that biological activity increased pH and provided the organic matter solid substrate which removed approximately 50% of the Zn and Cd. Zn removal was partially reversible as pH decreased. These observations reinforce the concept that both inorganic and organic carbon chemistry must be measured if significant. advances in our understanding of the attenuation of Zn and Cd from ARD sources are to be made.


Subject(s)
Cadmium/metabolism , Mining , Waste Disposal, Fluid/methods , Zinc/metabolism , Adsorption , Cadmium/analysis , Environmental Monitoring , Hydrogen-Ion Concentration , Soil Microbiology , Water Microbiology , Water Movements , Zinc/analysis
SELECTION OF CITATIONS
SEARCH DETAIL
...