HDAC6 selective inhibition of melanoma patient T-cells augments anti-tumor characteristics.

BACKGROUND: Therapies targeting anti-tumor T-cell responses have proven successful in the treatment of a variety of malignancies. However, as most patients still fail to respond, approaches to augment immunotherapeutic efficacy are needed. Here, we investigated the ability of histone deacetylase 6 (HDAC6)-selective inhibitors to decrease immunosuppression and enhance immune function of melanoma patient T-cells in ex vivo cultures. METHODS: T-cells were harvested from peripheral blood or tumor biopsies of metastatic melanoma patients and cultured in the presence of pan-, class-specific or class-selective histone deacetylase (HDAC) inhibitors. Changes in cytokine production were evaluated by Luminex and intracellular flow cytometry staining. Expression of surface markers, transcription factors, protein phosphorylation, and cell viability were assessed by flow cytometry. Changes in chromatin structure were determined by ATAC-seq. RESULTS: T-cell viability was impaired with low doses of pan-HDAC inhibitors but not with specific or selective HDAC inhibitors. The HDAC6-selective inhibitors ACY-1215 (ricolinostat) and ACY-241 (citarinostat) decreased Th2 cytokine production (i.e. IL-4, IL-5, IL-6, IL-10 and IL-13). Expansion of peripheral blood T-cells from melanoma patients in the presence of these inhibitors resulted in downregulation of the Th2 transcription factor GATA3, upregulation of the Th1 transcription factor T-BET, accumulation of central memory phenotype T-cells (CD45RA-CD45RO + CD62L + CCR7+), reduced exhaustion-associated phenotypes (i.e. TIM3 + LAG3 + PD1+ and EOMES+PD1+), and enhanced killing in mixed lymphocyte reactions. The frequency, FOXP3 expression, and suppressive function of T regulatory cells (Tregs) were decreased after exposure to ACY-1215 or ACY-241. Higher frequencies of T-cells expressing CD107a + IFNγ+ and central memory markers were observed in melanoma tumor-infiltrating lymphocytes (TIL), which persisted after drug removal and further expansion. After ACY-1215 treatment, increased chromatin accessibility was observed in regions associated with T-cell effector function and memory phenotypes, while condensed chromatin was found in regions encoding the mTOR downstream molecules AKT, SGK1 and S6K. Decreased phosphorylation of these proteins was observed in ACY-1215 and ACY-241-treated T-cells. AKT- and SGK1-specific inhibition recapitulated the increase in central memory frequency and decrease in IL-4 production, respectively, similar to the observed effects of HDAC6-selective inhibition. CONCLUSIONS: HDAC6-selective inhibitors augmented melanoma patient T-cell immune properties, providing a rationale for translational investigation assessing their potential clinical efficacy.

HDAC1,2 inhibition and doxorubicin impair Mre11-dependent DNA repair and DISC to override BCR-ABL1-driven DSB repair in Philadelphia chromosome-positive B-cell precursor acute lymphoblastic leukemia.

Philadelphia chromosome-positive (Ph+) B-cell precursor acute lymphoblastic leukemia (ALL) expressing BCR-ABL1 oncoprotein is a major subclass of ALL with poor prognosis. BCR-ABL1-expressing leukemic cells are highly dependent on double-strand break (DSB) repair signals for their survival. Here we report that a first-in-class HDAC1,2 selective inhibitor and doxorubicin (a hyper-CVAD chemotherapy regimen component) impair DSB repair networks in Ph+ B-cell precursor ALL cells using common as well as distinct mechanisms. The HDAC1,2 inhibitor but not doxorubicin alters nucleosomal occupancy to impact chromatin structure, as revealed by MNase-Seq. Quantitative mass spectrometry of the chromatin proteome along with functional assays showed that the HDAC1,2 inhibitor and doxorubicin either alone or in combination impair the central hub of DNA repair, the Mre11-Rad51-DNA ligase 1 axis, involved in BCR-ABL1-specific DSB repair signaling in Ph+ B-cell precursor ALL cells. HDAC1,2 inhibitor and doxorubicin interfere with DISC (DNA damage-induced transcriptional silencing in cis)) or transcriptional silencing program in cis around DSB sites via chromatin remodeler-dependent and -independent mechanisms, respectively, to further impair DSB repair. HDAC1,2 inhibitor either alone or when combined with doxorubicin decreases leukemia burden in vivo in refractory Ph+ B-cell precursor ALL patient-derived xenograft mouse models. Overall, our novel mechanistic and preclinical studies together demonstrate that HDAC1,2 selective inhibition can overcome DSB repair 'addiction' and provide an effective therapeutic option for Ph+ B-cell precursor ALL.

Stunting of Onion in the Columbia Basin of Oregon and Washington Caused by Rhizoctonia spp.

During 2009 and 2010, 45 isolates of Rhizoctonia spp. were recovered from onion bulb crops in the semiarid Columbia Basin of Oregon and Washington, in which patches of severely stunted onion plants developed following rotation with winter cereal cover crops. Characterization of isolates recovered from naturally infested soil and roots was performed by sequence analysis of the ribosomal DNA (rDNA) internal transcribed spacer region, with the majority of isolates (64%) identified as Rhizoctonia solani. In steam-pasteurized field soil, stunting of onion was caused by isolates of R. solani anastamosis groups (AGs) 2-1, 3, 4, and 8, as well as Waitea circinata var. circinata and binucleate Rhizoctonia AG E evaluated at 13 and 8 or 15 and 15°C day and night temperatures, respectively, typical of spring planting conditions in the Columbia Basin. Isolates of R. solani AG 5 as well as binucleate AG A and I were nonpathogenic. The most virulent isolates belonged to AG 8, although an AG 3 and an AG E isolate were also highly virulent. Isolates of AG 2-1 and 3 caused moderate levels of disease, while isolates of AG 4 and W. circinata var. circinata caused low levels of disease. Emergence was reduced by isolates of AG 2-1, 3, and E. When the various AGs were grown at temperatures of 5 to 30°C, the relative growth rate of the Rhizoctonia isolates was not positively correlated with virulence on onion within an AG.

NMR analysis of metabolic responses to extreme conditions of the temperature-dependent coral pathogen Vibrio coralliilyticus.

AIMS: To identify and understand the presence of metabolites responsible for the variation in the metabolic profile of Vibrio coralliilyticus under extreme conditions. METHODS AND RESULTS: Multiple batches of V. coralliilyticus were grown under normal conditions. Four samples in one batch were subjected to extreme conditions via a freeze-thaw cycle during lyophilization. Polar metabolites were extracted using a combination of methanol, water and heat. Nuclear magnetic resonance (NMR)-based metabolic profiles indicated significant differences between the normal and stressed samples. Three compounds identified in the stressed metabolome were maltose, ethanolamine, and the bioplastic-type compound (BTC) 2-butenoic acid, 2-carboxy-1-methylethyl ester. This is the first report of the production of this BTC by V. coralliilyticus. CONCLUSIONS: The presence of maltose and ethanolamine indicates a state of acute nutrient limitation; therefore, we hypothesize that the cell's metabolism turned to its own cell wall, or perhaps neighbouring cells, for sources of carbon and nitrogen. The presence of the BTC also supports the acute nutrient limitation idea because of the parallels with polyhydroxyalkanoate (PHA) production in other gram-negative bacteria, including other Vibrio species. SIGNIFICANCE AND IMPACT OF THE STUDY: Recent metabolomics research on the temperature-dependent coral pathogen V. coralliilyticus has led to the discovery of several compounds produced by the organism as a response to high density, low nutrient conditions. The three metabolites, along with (1) H NMR metabolic fingerprints of the nutrient limited samples, are proposed to serve as metabolic markers for extremely stressful conditions of V. coralliilyticus.

Control of Common Bunt in Organic Wheat.

Common bunt, caused by the seedborne and soilborne pathogens Tilletia caries and T. laevis, has re-emerged as a major disease in organic wheat. In conventional agriculture, common bunt is routinely managed with the use of synthetic chemical seed treatments. For this reason, common bunt is a relatively unimportant disease in conventional agriculture. However, since synthetic chemical inputs are prohibited in organic agriculture, common bunt is a major threat once more in organic wheat and seed production. The challenge today is to manage the disease without the use of chemical seed treatments. This review reports on the management of common bunt under organic farming systems, mainly through host resistance and organic seed treatments. We report the history of screening wheat germplasm for bunt resistance, the search for new sources of resistance, and identification and mapping of bunt resistance genes. Since the pathogen has a gene-for-gene relationship with the host, this review also includes a summary of work on pathogen race identification and virulence patterns of field isolates. Also included are studies on the physiological and molecular basis of host resistance. Alternative seed treatments are discussed, including physical seed treatments, and microbial-based and plant-based treatments acceptable in organic systems. The article concludes with a brief discussion on the current gaps in research on the management of common bunt in organic wheat.

Cellulitis incidence in a defined population.

A population-based insurance claims database was used to examine cellulitis incidence, anatomical sites of infection, complicating diagnoses, source of health service, and recurrence rates. Insurance claim files were searched for cellulitis ICD-9-CM codes 681.0-682.9. Complications of cellulitis including erysipelas, lymphadenitis, lymphangitis, and necrotizing fasciitis were also identified by ICD-9-CM codes. We found a cellulitis incidence rate of 24.6/1000 person-years, with a higher incidence among males and individuals aged 45-64 years. The most common site of infection was the lower extremity (39.9%). The majority of patients were seen in an outpatient setting (73.8%), and most (82.0%) had only one episode of cellulitis during the 5-year period studied. There was a very low incidence of cellulitis complications, including necrotizing fasciitis. Cellulitis is fairly common, usually treated in outpatient settings, and is infrequently complicated by erysipelas, lymphadenitis, lymphangitis, or necrotizing fasciitis.

Resistance to eyespot of wheat, caused by Tapesia yallundae, derived from Thinopyrum intermedium homoeologous group 4 chromosome.

Thinopyrum intermedium was identified previously as resistant to Tapesia yallundae, cause of eyespot of wheat. Using GUS-transformed isolates of T. yallundae as inoculum, we determined that wheat lines carrying Th. intermedium chromosome 4 Ai#2 or the short arm of chromosome 4 Ai#2 were as resistant to the pathogen as the eyespot-resistant wheat- Th. ponticum chromosome substitution line SS 767 (PI 611939) and winter wheat cultivar Madsen, which carries gene Pch 1 for eyespot resistance. Chromosome 4 E from Th. elongatum and chromosome 4 J from Th. bessarabicum did not confer resistance to T. yallundae. Genome-specific PCR primers confirmed the presence of Thinopyrum chromatin in these wheat- Thinopyrum lines. Genomic in situ hybridization using an St genomic probe from Pseudoroegneria strigosa demonstrated that chromosome 4 Ai#2 belongs to the J(s) genome of Thinopyrum. The eyespot resistance in the wheat- Th. intermedium lines is thus controlled by the short arm of this J(s) chromosome. This is the first report of resistance to T. yallundae controlled by a J(s) genome chromosome of Th. intermedium.

A New Source of Resistance to Tapesia yallundae Associated with a Homoeologous Group 4 Chromosome in Thinopyrum ponticum.

ABSTRACT Wheat (Thinopyrum ponticum line SS767; PI 611939) with 42 chromosomes previously was identified as a new source of eyespot resistance. Individual plants of SS767 were tested for reaction to Tapesia yallundae, the major pathogen of eyespot in the Pacific Northwest region of the United States. Resistance of this line was similar to the resistant winter wheat cv. Madsen (carrying gene Pch1 for eyespot resistance). Polymerase chain reaction analysis with primers specific for the J or E genomes revealed that SS767 contains Thinopyrum chromatin. Cytological and Cbanding analyses demonstrated that SS767 is a chromosome substitution line in which wheat chromosome 4D is replaced by a homoeologous group 4 chromosome of Thinopyrum ponticum. Genomic in situ hybridization using St genomic DNA from Pseudoroegneria strigosa as a probe, which can differentiate chromosomes from different genomes of Thinopyrum, indicated that this chromosome belongs to the J genome. Molecular analysis of an F(2) population segregating for chromosome 4J and resistance to eyespot confirmed that eyespot resistance in line SS767 is associated with chromosome 4J of Thinopyrum ponticum. This is the first report of genetic control of resistance to eyespot derived from Thinopyrum ponticum. This source of resistance provides a new opportunity to improve wheat resistance to eyespot by adding to the diversity of resistance sources available.

Perennial Wheat Germ Plasm Lines Resistant to Eyespot, Cephalosporium Stripe, and Wheat Streak Mosaic.

A perennial wheat cropping system on the Palouse Prairie of eastern Washington may provide an alternative to the Federal Conservation Reserve Program and reduce soil erosion while providing a harvestable crop for growers. Twenty-four perennial wheat germ plasm lines resulting from crosses between wheat and wheatgrass were evaluated under controlled environment conditions for resistance to Wheat streak mosaic virus (WSMV), Cephalosporium gramineum, and Tapesia yallundae (anamorph Pseudocercosporella herpotrichoides var. herpotrichoides). Perennial wheat lines SS452, SS103, SS237, MT-2, and PI 550713 were resistant to all three pathogens. Eight lines (33%) were resistant to WSMV at 21°C and 25°C; AT3425 was resistant to WSMV at 21°C but not at 25°C. Thirteen lines (54%) were highly to moderately resistant to C. gramineum. Thirteen lines (54%) were resistant to T. yallundae in each experiment, but the reactions of four lines differed between experiments. The wheatgrasses Thinopyrum intermedium (PI 264770) and Thinopyrum ponticum (PI 206624) are reported as new sources of resistance to T. yallundae. Perennial wheat must have resistance to these diseases in order to be feasible as a crop in the Pacific Northwest.

Evaluation of the effectiveness of a Web-based graduate epidemiology course.

An online epidemiology course was developed, implemented, and evaluated for graduate nursing students through the collaborative efforts of nursing faculty and information, education, and instructional design staff of the library at a health sciences university. This epidemiology course is a core curriculum course for graduate nursing students. The course was piloted with 14 students (one student in Romania); the initial online offering ran concurrently with a traditional classroom section. Extensive evaluation data were collected and analyzed to compare the effectiveness of the classroom and distance-learning formats. Areas of evaluation included objective measures, such as midterm and final examination scores and content analysis comparisons, as well as subjective ratings by the students of time commitments, course objectives, technical aspects of the web-based course, areas of satisfaction or dissatisfaction, and self-confidence regarding epidemiology and computer skills. Recommendations for course development, implementation, and evaluation for similar distance-learning courses will be included.

Evaluation of Dasypyrum villosum Populations for Resistance to Cereal Eyespot and Stripe Rust Pathogens.

Resistance to Pseudocercosporella herpotrichoides (cause of eyespot) and Puccinia striiformis(cause of stripe rust) was evaluated in a germ plasm collection of Dasypyrum villosum (syn. Haynaldia villosa) and a set of disomic addition lines, a substitution, and a translocation line of D. villosum chromosomes in a wheat background. Three races of P. striiformis and a ß-glucuronidase-transformed strain of Pseudocercosporella herpotrichoides were used to inoculate plants and evaluate disease reactions. Of the 115 D. villosum accessions tested, 33 (28.6%) were resistant to one or more races of Puccinia striiformis and 8 accessions were resistant to all races. All 219 accessions of D. villosum tested were resistant to Pseudocercosporella herpotrichoides and 158 (72%) of the accessions had lower ß-glucuronidase activity than the resistant wheat line VPM-1. Most of the accessions of D. villosum resistant to the stripe rust pathogen originated from Greece; however, there was no distinction among origins for resistance to the eyespot pathogen. Chromosome 4V was confirmed to carry the gene for resistance to P. herpotrichoides. At least one gene for resistance to Puccinia striiformis was located on the short arm of chromosome 6V of D. villosum in the 6VS/6AL-translocation line; this gene was named Yr26.

The initiation of distance learning at Thomas Jefferson University: the library as integral partner.

In 1998 Thomas Jefferson University offered its first entirely online course. Librarians and library staff were integral in the development, support, evaluation, and refinement of this course. While staff members may have taken non-traditional roles in this effort, their roles generally fell within the broad guidelines of assisting University faculty with information and knowledge management. The development and support of distance course offerings will continue to be a focus at Scott Memorial Library.

Molecular cytogenetic characterization of Thinopyrum and wheat-Thinopyrum translocated chromosomes in a wheat-Thinopyrum amphiploid.

The wheat-Thinopyrum amphiploid 'Agrotriticum # 3425' (AT 3425), which is highly resistant to Cephalosporium stripe, was identified to carry seven pairs of Thinopyrum chromosomes, three pairs of wheat-Thinopyrum translocated chromosomes and 18 pairs of wheat chromosomes. Fluorescence genomic in situ hybridization (FGISH), C-banding, sequential C-banding and FGISH, and denaturing polyacrylamide gel electrophoresis (SDS-PAGE) were used to characterize and identify the chromosomes. The Thinopyrum chromosomes in AT 3425 were designated as T1 through T7 based on their C-banding patterns. The FGISH and C-banding patterns of mitotic chromosomes in AT 3425 and meiotic chromosomes in the hybrid between AT 3425 and wheat cultivar 'Chinese Spring' (CS) revealed that wheat chromosomes 1D, 2B and 3D were involved in the three wheat-Thinopyrum chromosome translocations designated as (W-T)1, (W-T)2, and (W-T)3 respectively. The analysis of high-molecular-weight glutenin subunits in single seeds of AT 3425 confirmed the involvement of wheat chromosome 1D in the translocation (W-T)1. The designations 1DSx1DL-1TL, 2BSx2BL-2TL and 3DSx3DL-3TL were suggested for the wheat-Thinopyrum translocated chromosomes (W-T)1, (W-T)2 and (W-T)3 in AT 3425 respectively.

Effects of laser in situ keratomileusis (LASIK) on the corneal endothelium.

PURPOSE: To assess the effects of laser in situ keratomileusis (LASIK) on the corneal endothelium. METHODS: In a prospective study, the corneal endothelium of 98 eyes of 65 consecutive patients (mean age, 41 years; range, 22 to 66 years) was photographed before, 2 weeks after, and 12 weeks after LASIK for the correction of 2.75 to 14.5 diopters of myopia. Theoretical ablation depths were 200 to 330 microm below the corneal surface. Cell density, coefficient of variation, and percent of hexagonal cells were determined using 150 to 200 cells from each image. Eighty-eight eyes (91%) of 59 patients had a history of contact lens wear. RESULTS: The mean+/-SD preoperative endothelial cell density was 2,549+/-365 cells per mm2, and the mean coefficient of variation was 0.35+/-0.06. There was no statistically significant change in the mean endothelial cell density or mean coefficient of variation of cell size at the 2-week (2,561+/-360 cells per mm2 and 0.35+/-0.06) or 12-week (2,541+/-364 cells per mm2 and 0.35+/-0.05) postoperative examinations. The percent of hexagonal cells was not significantly changed 2 weeks postoperatively; however, 12 weeks postoperatively (P=.0413, two-tailed t test), the percent of hexagonal cells was decreased by 1%. CONCLUSIONS: Corneal endothelial cell density and morphology were unchanged 2 and 12 weeks after LASIK for the correction of up to 14.5 diopters of myopia. In this LASIK study, the correction of up to 14.5 diopters of myopia appears to cause no clinically significant effect on corneal endothelial cell density or morphology.

Partial characterization of glutathione S-transferases from wheat (Triticum spp.) and purification of a safener-induced glutathione S-transferase from Triticum tauschii.

Hexaploid wheat (Triticum aestivum L.) has very low constitutive glutathione S-transferase (GST) activity when assayed with the chloroacetamide herbicide dimethenamid as a substrate, which may account for its low tolerance to dimethenamid in the field. Treatment of seeds with the herbicide safener fluxofenim increased the total GST activity extracted from T. aestivum shoots 9-fold when assayed with dimethenamid as a substrate, but had no effect on glutathione levels. Total GST activity in crude protein extracts from T. aestivum, Triticum durum, and Triticum tauschii was separated into several component GST activities by anion-exchange fast-protein liquid chromatography. These activities (isozymes) differed with respect to their activities toward dimethenamid or 1-chloro-2,4-dinitrobenzene as substrates and in their levels of induction by safener treatment. A safener-induced GST isozyme was subsequently purified by anion-exchange and affinity chromatography from etiolated shoots of the diploid wheat species T. tauschii (a progenitor of hexaploid wheat) treated with the herbicide safener cloquintocet-mexyl. The isozyme bound to a dimethenamid-affinity column and had a subunit molecular mass of 26 kD based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified enzyme (designated GST TSI-1) was recognized by an antiserum raised against a mixture of maize (Zea mays) GSTs. Amino acid sequences obtained from protease-digested GST TSI-1 had significant homology with the safener-inducible maize GST V and two auxin-regulated tobacco (Nicotiana tabacum) GST isozymes.

Identification of an RFLP interval containing Pch2 on chromosome 7AL in wheat.

The gene Pch2 in 'Cappelle Desprez' is one of two genes found in hexaploid wheat known to confer resistance to eyespot disease. This study was conducted to develop an RFLP linkage map of the distal portion of wheat chromosome 7AL, and to locate and identify markers closely associated with Pch2 for use in marker-assisted selection. Ten loci in addition to Pch2 were mapped on chromosome 7AL, using segregation data from 102 homozygous chromosome 7A recombinant substitution lines derived from 'Chinese Spring' x 'Chinese Spring' ('Cappelle Desprez' 7A). The Pch2 locus was bracketed by two RFLP markers, one 11.0 cM distal to Xcdo347 and the other 18.8 cM proximal to Xwg380. The position of Pch2 on chromosome 7AL is similar to that of Pch1 on chromosome 7DL, suggesting that these resistance genes are homoeoloci. Although no single marker was closely linked to Pch2, simultaneous selection of the flanking RFLP markers Xcdo347 and Xwg380 could be used for selecting Pch2, since double recombination occurred in only 3% of the recombinant population. The use of the flanking RFLP markers to select for Pch2, in combination with previously identified Pch1-linked markers, would facilitate the development of cultivars carrying two genes for resistance to eyespot.

A novel cytosolic calcium-independent phospholipase A2 contains eight ankyrin motifs.

We report the purification, molecular cloning, and expression of a novel cytosolic calcium-independent phospholipase A2 (iPLA2) from Chinese hamster ovary cells, which lacks extended homology to other phospholipases. iPLA2 is an 85-kDa protein that exists as a multimeric complex of 270-350 kDa with a specific activity of 1 micromol/min/mg. The full-length cDNA clone encodes a 752-amino acid cytoplasmic protein with one lipase motif (GXS465XG) and eight ankyrin repeats. Expression of the cDNA in mammalian cells generates an active 85-kDa protein. Mutagenesis studies show that Ser465 and the ankyrin repeats are required for activity. We demonstrate that iPLA2 selectively hydrolyzes the sn-2 over sn-1 fatty acid by 5-fold for 1,2-dipalmitoyl phosphatidylcholine in a mixed micelle. Moreover, we found the fatty acid preference at the sn-2 position to be highly dependent upon substrate presentation. However, iPLA2 does have a marked preference for 1,2-dipalmitoyl phosphatidic acid presented in a vesicle, generating the lipid second messenger lysophosphatidic acid. Finally the enzyme is able to hydrolyze the acetyl moiety at the sn-2 position of platelet-activating factor.

Identity between the Ca2+-independent phospholipase A2 enzymes from P388D1 macrophages and Chinese hamster ovary cells.

A novel Ca2+-independent phospholipase A2 (iPLA2) has recently been purified and characterized from P388D1 macrophages (Ackermann, E. J., Kempner, E. S., and Dennis, E. A. (1994) J. Biol. Chem. 269, 9227-9233). This enzyme appears to play a key role in regulating basal phospholipid remodeling reactions. Also an iPLA2 from Chinese hamster ovary (CHO) cells has been purified, molecularly cloned, and expressed (Tang, J., Kriz, R., Wolfman, N., Shaffer, M., Seehra, J., and Jones, S. S. (1997) J. Biol. Chem. 272, 8567-8575). We report herein that the cloned CHO iPLA2 is equivalent to the mouse enzyme purified from P388D1 cells. Polymerase chain reaction amplification of cDNA fragments from P388D1 cells using primers based on the CHO iPLA2 sequence, revealed a high degree of homology between the mouse and hamster enzymes at both the nucleotide and amino acid levels (92 and 95%, respectively). Identity between the two proteins was further demonstrated by using immunochemical, pharmacological, and biochemical approaches. Thus, an antiserum generated against the CHO enzyme recognized the P388D1 cell enzyme and gave similar molecular masses (about 83 kDa) for the two enzymes under the same experimental conditions. Further, the CHO enzyme has exactly the same sensitivity to inhibition by a variety of compounds previously shown to inhibit the P388D1 enzyme, including bromoenol lactone, palmitoyl trifluoromethyl ketone, and methyl arachidonyl fluorophosphonate. Additionally, covalent modification of the CHO enzyme by [3H]bromoenol lactone is dependent on active enzyme as is the P388D1 iPLA2. Finally, both enzymes have the same specific activities under identical experimental conditions.

Imitation or exploration? Young infants' matching of adults' oral gestures.

The claim that very young infants can imitate rests largely on reports that infants match adult displays of mouth opening (MO) and tongue protrusion (TP). Recent reviews suggest that only tongue protruding is reliably matched by young infants. This study tests the proposal that infants' "imitation" of tongue protruding reflects a coincidental match between a sight that infants find interesting and a behavior by which infants express interest. In Study 1, 4-week-old infants who looked longer at a nonsocial light display also produced TPs at higher rates than infants showing less interest. In Study 2, 4-week-old infants showed more interest (looked longer at) a tongue-protruding adult face than a mouth-opening face. Study 3 tracked 2 infants' responses to interesting objects for several weeks before and after the onset of manual reaching. Both infants produced tongue protrusions in response to objects within reach before but not after reaching developed. Together, the results of the 3 studies suggest that infants' tongue protrusions in response to a tongue-protruding adult reflect very early attempts at oral exploration of interesting objects.