Comparative kinase and cancer cell panel profiling of kinase inhibitors approved for clinical use from 2018 to 2020.

During the last two decades, kinase inhibitors have become the major drug class for targeted cancer therapy. Although the number of approved kinase inhibitors increases rapidly, comprehensive in vitro profiling and comparison of inhibitor activities is often lacking in the public domain. Here we report the extensive profiling and comparison of 21 kinase inhibitors approved by the FDA for oncology indications since June 2018 and 13 previously approved comparators on panels of 255 biochemical kinase assays and 134 cancer cell line viability assays. Comparison of the cellular inhibition profiles of the EGFR inhibitors gefitinib, dacomitinib, and osimertinib identified the uncommon EGFR p.G719S mutation as a common response marker for EGFR inhibitors. Additionally, the FGFR inhibitors erdafitinib, infigratinib, and pemigatinib potently inhibited the viability of cell lines which harbored oncogenic alterations in FGFR1-3, irrespective of the specific clinical indications of the FGFR inhibitors. These results underscore the utility of in vitro kinase inhibitor profiling in cells for identifying new potential stratification markers for patient selection. Furthermore, comparison of the in vitro inhibition profiles of the RET inhibitors pralsetinib and selpercatinib revealed they had very similar biochemical and cellular selectivity. As an exception, an NTRK3 fusion-positive cell line was potently inhibited by pralsetinib but not by selpercatinib, which could be explained by the targeting of TRK kinases in biochemical assays by pralsetinib but not selpercatinib. This illustrates that unexpected differences in cellular activities between inhibitors that act through the same primary target can be explained by subtle differences in biochemical targeting. Lastly, FLT3-mutant cell lines were responsive to both FLT3 inhibitors gilteritinib and midostaurin, and the PI3K inhibitor duvelisib. Biochemical profiling revealed that the FLT3 and PI3K inhibitors targeted distinct kinases, indicating that unique dependencies can be identified by combined biochemical and cellular profiling of kinase inhibitors. This study provides the first large scale kinase assay or cell panel profiling study for newly approved kinase inhibitors, and shows that comprehensive in vitro profiling of kinase inhibitors can provide rationales for therapy selection and indication expansion of approved kinase inhibitors.

Pharmacological validation of TDO as a target for Parkinson's disease.

Parkinson's disease patients suffer from both motor and nonmotor impairments. There is currently no cure for Parkinson's disease, and the most commonly used treatment, levodopa, only functions as a temporary relief of motor symptoms. Inhibition of the expression of the L-tryptophan-catabolizing enzyme tryptophan 2,3-dioxygenase (TDO) has been shown to inhibit aging-related α-synuclein toxicity in Caenorhabditis elegans. To evaluate TDO inhibition as a potential therapeutic strategy for Parkinson's disease, a brain-penetrable, small molecule TDO inhibitor was developed, referred to as NTRC 3531-0. This compound potently inhibits human and mouse TDO in biochemical and cell-based assays and is selective over IDO1, an evolutionary unrelated enzyme that catalyzes the same reaction. In mice, NTRC 3531-0 increased plasma and brain L-tryptophan levels after oral administration, demonstrating inhibition of TDO activity in vivo. The effect on Parkinson's disease symptoms was evaluated in a rotenone-induced Parkinson's disease mouse model. A structurally dissimilar TDO inhibitor, LM10, was evaluated in parallel. Both inhibitors had beneficial effects on rotenone-induced motor and cognitive dysfunction as well as rotenone-induced dopaminergic cell loss and neuroinflammation in the substantia nigra. Moreover, both inhibitors improved intestinal transit and enhanced colon length, which indicates a reduction of the rotenone-induced intestinal dysfunction. Consistent with this, mice treated with TDO inhibitor showed decreased expression of rotenone-induced glial fibrillary acidic protein, which is a marker of enteric glial cells, and decreased α-synuclein accumulation in the enteric plexus. Our data support TDO inhibition as a potential therapeutic strategy to decrease motor, cognitive, and gastrointestinal symptoms in Parkinson's disease.

Chemotherapy sensitivity testing on ovarian cancer cells isolated from malignant ascites.

BACKGROUND: In epithelial ovarian cancer (EOC), 15-20% of the tumors do not respond to first-line chemotherapy (paclitaxel with platinum-based therapy), and in recurrences this number increases. Our aim is to determine the feasibility of cell proliferation assays of tumor cells isolated from malignant ascites to predict in vitro chemotherapy sensitivity, and to correlate these results with clinical outcome. MATERIALS AND METHODS: Ascites was collected from twenty women with advanced EOC. Cell samples were enriched for tumor cells and EOC origin was confirmed by intracellular staining of CK7, surface staining of CA125 and EpCAM, and HE4 gene expression. In vitro sensitivity to chemotherapy was determined in cell proliferation assays using intracellular ATP content as an indirect measure of cell number. In vitro drug response was quantified by calculation of the drug concentration at which cell growth was inhibited with 50%. Clinical outcome was determined using post-treatment CA125 level. RESULTS: Cell samples of twenty patients were collected, of which three samples that failed to proliferate were excluded in the analysis (15%). Three other samples were excluded, because clinical outcome could not be determined correctly. In twelve of the fourteen remaining cases (86%) in vitro drug sensitivity and clinical outcome corresponded, while in two samples (14%) there was no correspondence. CONCLUSIONS: Our study demonstrates the feasibility of drug sensitivity tests using tumor cells isolated from ascites of advanced EOC patients. Larger observational studies are required to confirm the correlation between the in vitro sensitivity and clinical outcome.

Targeting Indoleamine 2,3-Dioxygenase in Cancer Models Using the Novel Small Molecule Inhibitor NTRC 3883-0.

Indoleamine 2,3-dioxygenase (IDO1) is a key regulator of immune suppression by catalyzing the oxidation of L-tryptophan. IDO1 expression has been related to poor prognosis in several cancers and to resistance to checkpoint immunotherapies. We describe the characterization of a novel small molecule IDO1 inhibitor, NTRC 3883-0, in a panel of biochemical and cell-based assays, and various cancer models. NTRC 3883-0 released the inhibitory effect of IDO1 on CD8-positive T cell proliferation in co-cultures of IDO1-overexpressing cells with healthy donor lymphocytes, demonstrating its immune modulatory activity. In a syngeneic mouse model using IDO1-overexpressing B16F10 melanoma cells, NTRC 3883-0 effectively counteracted the IDO1-induced modulation of L-tryptophan and L-kynurenine levels, demonstrating its in vivo target modulation. Finally, we studied the expression and activity of IDO1 in primary cell cultures established from the malignant ascites of ovarian cancer patients. In these cultures, IDO1 expression was induced upon stimulation with IFNγ, and its activity could be inhibited by NTRC 3883-0. Based on these results, we propose the use of ascites cell-based functional assays for future patient stratification. Our results are discussed in light of the recent discontinuation of clinical trials of more advanced IDO1 inhibitors and the reconsideration of IDO1 as a valid drug target.

Cell Panel Profiling Reveals Conserved Therapeutic Clusters and Differentiates the Mechanism of Action of Different PI3K/mTOR, Aurora Kinase and EZH2 Inhibitors.

Cancer cell line panels are important tools to characterize the in vitro activity of new investigational drugs. Here, we present the inhibition profiles of 122 anticancer agents in proliferation assays with 44 or 66 genetically characterized cancer cell lines from diverse tumor tissues (Oncolines). The library includes 29 cytotoxics, 68 kinase inhibitors, and 11 epigenetic modulators. For 38 compounds this is the first comparative profiling in a cell line panel. By strictly maintaining optimized assay protocols, biological variation was kept to a minimum. Replicate profiles of 16 agents over three years show a high average Pearson correlation of 0.8 using IC50 values and 0.9 using GI50 values. Good correlations were observed with other panels. Curve fitting appears a large source of variation. Hierarchical clustering revealed 44 basic clusters, of which 26 contain compounds with common mechanisms of action, of which 9 were not reported before, including TTK, BET and two clusters of EZH2 inhibitors. To investigate unexpected clusterings, sets of BTK, Aurora and PI3K inhibitors were profiled in biochemical enzyme activity assays and surface plasmon resonance binding assays. The BTK inhibitor ibrutinib clusters with EGFR inhibitors, because it cross-reacts with EGFR. Aurora kinase inhibitors separate into two clusters, related to Aurora A or pan-Aurora selectivity. Similarly, 12 inhibitors in the PI3K/AKT/mTOR pathway separated into different clusters, reflecting biochemical selectivity (pan-PI3K, PI3Kßγδ-isoform selective or mTOR-selective). Of these, only allosteric mTOR inhibitors preferentially targeted PTEN-mutated cell lines. This shows that cell line profiling is an excellent tool for the unbiased classification of antiproliferative compounds. Mol Cancer Ther; 15(12); 3097-109. ©2016 AACR.

International Multicenter Study on the Impact of Extracapsular Lymph Node Involvement in Primary Surgery Adenocarcinoma of the Esophagus on Overall Survival and Staging Systems.

OBJECTIVE: The current pathological lymph node (pN) staging is based on the number of positive lymph nodes but does not take into consideration characteristics of the involved lymph nodes itself. The current study aims to examine the prognostic value of extracapsular lymph node involvement (EC-LNI) and intracapsular lymph node involvement (IC-LNI) for esophageal adenocarcinoma treated by primary surgery. METHODS: From the databases of five European high volume centers, 1639 adenocarcinoma patients with primary R0-resection were withheld after excluding 90-day mortality. Oncologic variables, including number of resected lymph nodes, number of resected positive lymph nodes, and EC-LNI/IC-LNI were examined. The Union Internationale contre le Cancer (UICC) 7th edition prognostic staging was used as baseline staging system. Statistical analysis was performed by Cox proportional hazards modeling and verified using the Random Survival Forest technique. RESULTS: EC-LNI showed significantly worse overall 5-year survival compared with IC-LNI overall (13.4% vs 37.2%, P < 0.0001), including in each pN-category [16.4% vs 45.6% in pN1 (P < 0.0001), 16.1% vs 23.8% (P = 0.047) in pN2 (P = 0.065), and 8.7% vs 26.3% in pN3 categories, respectively]. pN1 IC-LNI patients show a 5-year overall survival comparable (P = 0.92) with stage IIB (ie, pT3N0). Reclassifying the UICC prognostic stages according to these findings into an adapted staging model showed a significant (P < 0.0001) increase in homogeneity, discriminatory ability, and monotonicity compared with the original UICC TNM 7th edition prognostic staging. CONCLUSIONS: These data suggest that lymph node capsular status is an important prognostic factor and should be considered for the future edition of the TNM staging system for esophageal cancer.

Selective Targeting of CTNBB1-, KRAS- or MYC-Driven Cell Growth by Combinations of Existing Drugs.

The aim of combination drug treatment in cancer therapy is to improve response rate and to decrease the probability of the development of drug resistance. Preferably, drug combinations are synergistic rather than additive, and, ideally, drug combinations work synergistically only in cancer cells and not in non-malignant cells. We have developed a workflow to identify such targeted synergies, and applied this approach to selectively inhibit the proliferation of cell lines with mutations in genes that are difficult to modulate with small molecules. The approach is based on curve shift analysis, which we demonstrate is a more robust method of determining synergy than combination matrix screening with Bliss-scoring. We show that the MEK inhibitor trametinib is more synergistic in combination with the BRAF inhibitor dabrafenib than with vemurafenib, another BRAF inhibitor. In addition, we show that the combination of MEK and BRAF inhibitors is synergistic in BRAF-mutant melanoma cells, and additive or antagonistic in, respectively, BRAF-wild type melanoma cells and non-malignant fibroblasts. This combination exemplifies that synergistic action of drugs can depend on cancer genotype. Next, we used curve shift analysis to identify new drug combinations that specifically inhibit cancer cell proliferation driven by difficult-to-drug cancer genes. Combination studies were performed with compounds that as single agents showed preference for inhibition of cancer cells with mutations in either the CTNNB1 gene (coding for ß-catenin), KRAS, or cancer cells expressing increased copy numbers of MYC. We demonstrate that the Wnt-pathway inhibitor ICG-001 and trametinib acted synergistically in Wnt-pathway-mutant cell lines. The ERBB2 inhibitor TAK-165 was synergistic with trametinib in KRAS-mutant cell lines. The EGFR/ERBB2 inhibitor neratinib acted synergistically with the spindle poison docetaxel and with the Aurora kinase inhibitor GSK-1070916 in cell lines with MYC amplification. Our approach can therefore efficiently discover novel drug combinations that selectively target cancer genes.

High-throughput fluorescence-based screening assays for tryptophan-catabolizing enzymes.

Indoleamine 2,3-dioxygenase (IDO1) and tryptophan 2,3-dioxygenase (TDO) are two structurally different enzymes that have a different tissue distribution and physiological roles, but both catalyze the conversion of tryptophan to N-formylkynurenine (NFK). IDO1 has been clinically validated as a small-molecule drug target for cancer, while preclinical studies indicate that TDO may be a target for cancer immunotherapy and neurodegenerative disease. We have developed a high-throughput screening assay for IDO1 and TDO based on a novel chemical probe, NFK Green, that reacts specifically with NFK to form a green fluorescent molecule with an excitation wavelength of 400 nm and an emission wavelength of 510 nm. We provide the first side-by-side comparison of a number of published inhibitors of IDO1 and TDO and reveal that the preclinical IDO1 inhibitor Compound 5l shows significant cross-reactivity with TDO, while the relative selectivity of other published inhibitors was confirmed. The suitability for high-throughput screening of the assays was demonstrated by screening a library of 87,000 chemical substances in 384- or 1536-well format. Finally, we demonstrate that the assay can also be used to measure the capacity of cells to metabolize tryptophan and to measure the cellular potency of IDO1 and TDO inhibitors.

Comparison of the cancer gene targeting and biochemical selectivities of all targeted kinase inhibitors approved for clinical use.

The anti-proliferative activities of all twenty-five targeted kinase inhibitor drugs that are in clinical use were measured in two large assay panels: (1) a panel of proliferation assays of forty-four human cancer cell lines from diverse tumour tissue origins; and (2) a panel of more than 300 kinase enzyme activity assays. This study provides a head-on comparison of all kinase inhibitor drugs in use (status Nov. 2013), and for six of these drugs, the first kinome profiling data in the public domain. Correlation of drug activities with cancer gene mutations revealed novel drug sensitivity markers, suggesting that cancers dependent on mutant CTNNB1 will respond to trametinib and other MEK inhibitors, and cancers dependent on SMAD4 to small molecule EGFR inhibitor drugs. Comparison of cellular targeting efficacies reveals the most targeted inhibitors for EGFR, ABL1 and BRAF(V600E)-driven cell growth, and demonstrates that the best targeted agents combine high biochemical potency with good selectivity. For ABL1 inhibitors, we computationally deduce optimized kinase profiles for use in a next generation of drugs. Our study shows the power of combining biochemical and cellular profiling data in the evaluation of kinase inhibitor drug action.

Residual aggregates in platelet products: what do we know?

BACKGROUND AND OBJECTIVES: Platelet (PLT) aggregates can occur during or after PLT component processing. However, very few reports investigating the phenomenon and its clinical significance have been published. In this review, currently available information about aggregates in PLT products is summarized and possible causal factors as well as preventive strategies are discussed. MATERIALS AND METHODS: A review of the MEDLINE® database for relevant publications from 1960 to May 2013 was conducted. RESULTS: It is well known that PLT aggregates may occur during or after the PLT product preparation process. These aggregates normally dissipate with rest and agitation. However, in some rare cases, the aggregates do not dissipate within 24 h and can persist up to the end of storage. Exposure to low temperature, low pH, short resting period after collection, different collection systems, presence of bubbles or foam inside the PLT bag, PLT-container interactions, proper product mixing and donor-dependent variables may have an impact on the formation of PLT aggregates. Although publications are rare, the presence of small numbers of PLT aggregates appears to have only limited impact on PLT in vitro quality. Furthermore, data on the clinical impact of PLT aggregates are lacking. CONCLUSION: Despite the fact that PLT aggregates occur in PLT products, published data on this topic remain scant. Considering the concern of clinicians about this phenomenon, more studies are needed which should focus on the possible clinical impact of such aggregates and precautions to avoid PLT aggregate formation in PLT products.

Multidimensional profiling of CSF1R screening hits and inhibitors: assessing cellular activity, target residence time, and selectivity in a higher throughput way.

Over the past years, improvements in high-throughput screening (HTS) technology and compound libraries have resulted in a dramatic increase in the amounts of good-quality screening hits, and there is a growing need for follow-on hit profiling assays with medium throughput to further triage hits. Here the authors present such assays for the colony-stimulating factor 1 receptor (CSF1R, Fms), including tests for cellular activity and a homogeneous assay to measure affinity for inactive CSF1R. They also present a high-throughput assay to measure target residence time, which is based on competitive binding kinetics. To better fit k(off) rates, they present a modified mathematical model for competitive kinetics. In all assays, they profiled eight reference inhibitors (imatinib, sorafenib, sunitinib, tandutinib, dasatinib, GW2580, Ki20227, and J&J's pyrido[2,3-d]pyrimidin-5-one). Using the known biochemical selectivities of these inhibitors, which can be quantified using metrics such as the selectivity entropy, the authors have determined which assay readout best predicts hit selectivity. Their profiling shows surprisingly that imatinib has a preference for the active form of CSF1R and that Ki20227 has an unusually slow target dissociation rate. This confirms that follow-on hit profiling is essential to ensure that the best hits are selected for lead optimization.

Characteristics of a new system for monitoring the leakage factor during regional hyperthermic isolated limb perfusion.

RATIONALE: A new system is presented and evaluated for real-time monitoring of blood leakage during hyperthermic isolated limb perfusion (HILP) surgery, the Veenstra HILP system. This system incorporates two software models to determine blood leakage: a single-nuclide algorithm and a newly developed dual-nuclide algorithm. The latter algorithm has the advantage that, in principle, it is independent of system sensitivity and thus independent of changes in geometrical efficiency. A physical description of the system is given, together with the required hardware and software specifications. METHODS: In-vitro measurements, corresponding to the intended clinical use, are presented to investigate the relevant performance characteristics of the system: count rate linearity, measurement uncertainty, response time, and accuracy. As the Veenstra HILP system provides the opportunity to use different filter settings and averaging time, the influence of these settings on the time response and measurement uncertainty is described. RESULTS: Count rate linearity was better than 1% for the count rate domain typically observed during HILP procedures. The response time of the system degrades with increasing total averaging time. In contrast, measurement uncertainty in the blood leakage factor improves with increasing radiotracer count rates and increasing total averaging time. For both blood leakage algorithms, measurement accuracy is better than 1.0 and 1.5%, respectively. CONCLUSION: Measurements have shown that the system is well suited for the real-time monitoring of blood leakage during HILP surgery. Furthermore, a good agreement was observed between the theoretical and measured response time and measurement uncertainty.

Collection of hyperconcentrated platelets with Trima Accel.

BACKGROUND AND OBJECTIVES: Lowering the plasma content in single-donor platelet (PLT) concentrates well below 30% implies the need to collect platelets at very high concentrations. Trima Accel (TA) is validated for collection below 4000 x 10(3) PLTs/microl. We evaluated its performance at 5000 x 10(3) PLTs/microl. MATERIALS AND METHODS: Twenty blood donors underwent apheresis with TA twice collecting either a hyperconcentrated or a standard single-donor platelet concentrate with a target platelet concentration of 5000 or 1200 x 10(3) PLTs/microl, respectively. We analysed the collection efficiency, the collection rate and the quality of the collected by-plasma. RESULTS: We collected 20 hyperconcentrated and 20 standard units containing 2.56 +/- 0.5 and 3.39 +/- 0.4 x 10(11) PLTs at a concentration of 4518 +/- 978 and 1374 +/- 166 x 10(3) PLTs/microl in 45 +/- 8 and 39 +/- 6 min resulting in a collection efficiency of 47.5 +/- 10.0 and 70.7 +/- 7.9% and a collection rate of 5.9 +/- 1.4 and 8.8 +/- 1.5 x 10(9) PLTs/min, respectively (all results expressed as mean +/- standard deviation). The collected by-plasma showed a very high grade of cell purity and a satisfactory recovery of the clotting factors. CONCLUSION: Although TA is a suitable device for PLT collection at very high concentrations, improvements are desirable to further increase the productivity above its currently validated upper collect concentration limit.

First comparison of productivity and citrate donor load between the Trima version 4 (dual-stage filler) and the Trima Accel (single-stage filler) in the same donors.

BACKGROUND AND OBJECTIVES: Aside from new software the blood cell separator TRIMA (GambroBCT) also received a newly designed separation chamber offering a novel single stage separation technology, called Trima Accel. We evaluated this new system focusing on productivity and donor comfort by comparing it to the previous version (Trima version 4) in collecting single-donor platelet concentrates (SD-PCs) and plasma. MATERIALS AND METHODS: Each of 20 donors underwent platelet apheresis using both devices. We compared the collection efficiency (CE), the collections rate (CR), the volume of the collected plasma and the residual leukocytes. Furthermore we compared donor comfort in terms of duration of the donation, flow of citrate back to the donor and platelet and white blood cell (WBC) loss. RESULTS: While the number of collected platelets and the platelet concentration did not differ significantly between both techniques the time of the procedure was reduced by 15.6% with Trima Accel. This results in an increase of the CR and CE of 25% and 15% respectively when using Trima Accel. Log normal probability plotting of WBC counts showed that both techniques complied with the European and the US leukoreduction guidelines. The mean flow of ACDA to the donor per minute and per litre blood volume was also reduced by 20%. CONCLUSION: These data show that the Trima Accel represents a further improvement in apheresis platelet production with a better productivity and donor comfort, especially regarding the mean flow of ACDA to the donor.

High-throughput screening with immobilized metal ion affinity-based fluorescence polarization detection, a homogeneous assay for protein kinases.

Protein kinases are one of the most important target classes in high-throughput screening today. The use of generic assay technologies facilitates assay development for new targets and decreases the time needed for implementation of assays in robotic screening. For tyrosine kinases, several generic assay technology platforms are available. These technologies make use of high-affinity antibodies that discriminate between phosphorylated tyrosines and non-phosphorylated tyrosines. Similar generic antibodies specific for phosphoserine or phosphothreonine are lacking. Recently, a non-antibody-based fluorescence polarization assay for protein kinases has become available, called IMAP (Molecular Devices, Sunnyvale, CA). In this assay, a fluorescently labeled peptide substrate that is phosphorylated by kinase is captured on metal-derivatized nanoparticles. We have evaluated IMAP in high-throughput screening, and compared this technology with a competition fluorescence polarization immunoassay based on an antibody specific for a phosphorylated peptide substrate. A random collection of >250000 compounds was screened with the two assays. Fluorescent library compounds were identified by calculation of fluorescence intensity values from the screening data, and by assaying in the absence of fluorescent reagents. Fluorescence polarization artifacts were filtered out further by testing in an ELISA-based kinase assay. Our data show that IMAP is a robust technology for high-throughput screening of kinase targets, and suggest that it is less susceptible to fluorescence polarization artifacts than the competition fluorescence polarization immunoassay.

A multicentre evaluation of a new filtration protocol for leucocyte depletion of high-haematocrit red blood cells collected by an automated blood collection system.

BACKGROUND AND OBJECTIVES: A multicentre trial was set up to evaluate the performance of a new leucodepletion protocol. MATERIALS AND METHODS: Filtration at high haematocrit was started during collection of red blood cell (RBC) products by apheresis with Trima. SAG-M was added after filtration through the filter. Haematocrits and haemoglobin of the filtered RBCs were measured. Residual leucocytes were determined by Nageotte counting. RESULTS: One-hundred and forty seven procedures were carried out. The haematocrit and haemoglobin contents were 57.3 +/- 3.0% and 55.1 +/- 4.3 g/unit, respectively. All products showed low residual leucocyte levels (< or = 0.75 x 106/unit; 99.31% < 1 x 106). CONCLUSION: Immediate, on-line, high-haematocrit filtration of red cells collected on Trima resulted in leucoreduced RBCs, which met the AABB and Council of Europe criteria.

A 4-year history of work redesign in two ICUs.

To understand caregiver activities and their associated costs, two intensive care units (ICUs) initiated a work redesign study. During 1 week each year, ICU employees recorded and summarized their activities in 5-minute blocks of time. Activities were analyzed; processes were evaluated and redesigned.

Reduction of exploratory behavior by intraperitoneal injection of interleukin-1 involves brain corticotropin-releasing factor.

The behavior of mice was scored in a multicompartment chamber one hour following intraperitoneal injection of recombinant human interleukin-1 (IL-1). Both IL-1 alpha and IL-1 beta dose-dependently reduced the mean duration for which mice were in contact with novel stimuli without altering measures of locomotor activity, such as movements between the compartments or rears. These behavioral changes resemble those previously observed with prior restraint or intracerebroventricular (ICV) injection of corticotropin-releasing factor (CRF). Effective doses were in the range 0.1-10 ng for IL-1 alpha, and 1-10 ng for IL-1 beta. The reduction in stimulus-contact times induced by 1 ng of IL-1 beta was reversed by prior ICV injection of the CRF antagonist, alpha-helical CRF9-41, suggesting that IL-1 causes secretion of brain CRF which in turn elicits the behavioral changes. These results indicate that peripheral administration of IL-1 alpha or IL-1 beta in low doses can alter behavior. They provide additional evidence that IL-1 administration stimulates brain CRF secretion, and that brain CRF can modulate exploratory behavior, and thus reinforces the concept that IL-1 administration can induce stress.

Recent applications of FT-IR spectroscopy to polymer systems.

Fourier transform infrared spectroscopy has recently become an important analytical method for investigation of many polymer systems. Several new methods, concerned primarily with digital subtraction of absorbance spectra, are presented. Applications of the method to synthetic polymer research include conformational and configurational analyses, elucidation of degradation mechanisms, and interactions with filler surfaces. Many researchers in the biopolymer and medical fields have utilized the sensitivity and digital data processing capabilities of FT-IR to obtain information inaccessible by other methods.