The genus Cryptotendipes Beck et Beck in Florida, with the description of a new species (Diptera: Chironomidae: Chironominae).

Species of the genus Cryptotendipes Beck et Beck in Florida are reviewed. Previous Florida records of C. casuarius (Townes) are shown to be misidentifications of C. emorsus (Townes). One species new for the state, C. pseudotener (Goetghebuer), is recorded and a new species, C. rutteri Epler, is described from pharate pupae and associated larval exuviae. Thus, a total of three species are known from the state. Keys are provided for adult males, pupae and larvae of these three species.

Phase I study of the checkpoint kinase 1 inhibitor GDC-0575 in combination with gemcitabine in patients with refractory solid tumors.

BACKGROUND: Checkpoint kinase 1 (Chk1) inhibition following chemotherapy-elicited DNA damage overrides cell cycle arrest and induces mitotic catastrophe and cell death. GDC-0575 is a highly-selective oral small-molecule Chk1 inhibitor that results in tumor shrinkage and growth delay in xenograft models. We evaluated the safety, tolerability, and pharmacokinetic properties of GDC-0575 alone and in combination with gemcitabine. Antitumor activity and Chk1 pathway modulation were assessed. PATIENTS AND METHODS: In this phase I open-label study, in the dose escalation stage, patients were enrolled in a GDC-0575 monotherapy Arm (1) or GDC-0575 combination with gemcitabine Arm (2) to determine the maximum tolerated dose. Patients in arm 2 received either i.v. gemcitabine 1000 mg/m2 (arm 2a) or 500 mg/m2 (arm 2b), followed by GDC-0575 (45 or 80 mg, respectively, as RP2D). Stage II enrolled disease-specific cohorts. RESULTS: Of 102 patients treated, 70% were female, the median age was 59 years (range 27-85), and 47% were Eastern Cooperative Oncology Group PS 0. The most common tumor type was breast (37%). The most frequent adverse events (all grades) related to GDC-0575 and/or gemcitabine were neutropenia (68%), anemia (48%), nausea (43%), fatigue (42%), and thrombocytopenia (35%). Maximum concentrations of GDC-0575 were achieved within 2 hours of dosing, and half-life was ∼23 hours. No pharmacokinetic drug-drug interaction was observed between GDC-0575 and gemcitabine. Among patients treated with GDC-0575 and gemcitabine, there were four confirmed partial responses, three occurring in patients with tumors harboring TP53 mutation. Pharmacodynamic data were consistent with GDC-0575 inhibition of gemcitabine-induced expression of pCDK1/2. CONCLUSION: GDC-0575 can be safely administered as a monotherapy and in combination with gemcitabine; however, overall tolerability with gemcitabine was modest. Hematological toxicities were frequent but manageable. Preliminary antitumor activity was observed but limited to a small number of patients with a variety of refractory solid tumors treated with GDC-0575 and gemcitabine. CLINICAL TRIAL NUMBER: NCT01564251.

Remarkable fly (Diptera) diversity in a patch of Costa Rican cloud forest: Why inventory is a vital science.

Study of all flies (Diptera) collected for one year from a four-hectare (150 x 266 meter) patch of cloud forest at 1,600 meters above sea level at Zurquí de Moravia, San José Province, Costa Rica (hereafter referred to as Zurquí), revealed an astounding 4,332 species. This amounts to more than half the number of named species of flies for all of Central America. Specimens were collected with two Malaise traps running continuously and with a wide array of supplementary collecting methods for three days of each month. All morphospecies from all 73 families recorded were fully curated by technicians before submission to an international team of 59 taxonomic experts for identification.        Overall, a Malaise trap on the forest edge captured 1,988 species or 51% of all collected dipteran taxa (other than of Phoridae, subsampled only from this and one other Malaise trap). A Malaise trap in the forest sampled 906 species. Of other sampling methods, the combination of four other Malaise traps and an intercept trap, aerial/hand collecting, 10 emergence traps, and four CDC light traps added the greatest number of species to our inventory. This complement of sampling methods was an effective combination for retrieving substantial numbers of species of Diptera. Comparison of select sampling methods (considering 3,487 species of non-phorid Diptera) provided further details regarding how many species were sampled by various methods.        Comparison of species numbers from each of two permanent Malaise traps from Zurquí with those of single Malaise traps at each of Tapantí and Las Alturas, 40 and 180 km distant from Zurquí respectively, suggested significant species turnover. Comparison of the greater number of species collected in all traps from Zurquí did not markedly change the degree of similarity between the three sites, although the actual number of species shared did increase.        Comparisons of the total number of named and unnamed species of Diptera from four hectares at Zurquí is equivalent to 51% of all flies named from Central America, greater than all the named fly fauna of Colombia, equivalent to 14% of named Neotropical species and equal to about 2.7% of all named Diptera worldwide. Clearly the number of species of Diptera in tropical regions has been severely underestimated and the actual number may surpass the number of species of Coleoptera.        Various published extrapolations from limited data to estimate total numbers of species of larger taxonomic categories (e.g., Hexapoda, Arthropoda, Eukaryota, etc.) are highly questionable, and certainly will remain uncertain until we have more exhaustive surveys of all and diverse taxa (like Diptera) from multiple tropical sites.        Morphological characterization of species in inventories provides identifications placed in the context of taxonomy, phylogeny, form, and ecology. DNA barcoding species is a valuable tool to estimate species numbers but used alone fails to provide a broader context for the species identified.

A new species of Dicrotendipes (Diptera: Chironomidae) from Florida.

A new species of Dicrotendipes is described in all life stages from Florida. Adults of this new species are nearly identical to D. modestus (Say); pupae are similar to D. modestus, D. neomodestus (Malloch) and D. tritomus (Kieffer); while the larvae are unique and were keyed by Epler (1992, 1995, 2001) as Dicrotendipes sp. A. The taxonomic status of D. modestus and D. pulsus (Walker) is discussed.

A rapid method of species identification of wild chironomids (Diptera: Chironomidae) via electrophoresis of hemoglobin proteins in sodium dodecyl sulfate polyacrylamide gel (SDS-PAGE).

Studying aquatic benthic macroinvertebrates (BMIs) in the field requires accurate taxonomic identification, which can be difficult and time consuming. Conventionally, head capsule morphology has been used to identify wild larvae of Chironomidae. However, due to the number of species and possible damage and/or deformity of their head capsules, another supporting approach for identification is needed. Here, we provide hemoglobin (Hb) protein in hemolymph of chironomids as a new biomarker that may help resolve some of the ambiguities and difficulties encountered during taxonomic identification. Chironomids collected from two locations in Maine and New Jersey, USA were identified to the genus level and in some cases to the species-level using head capsule and body morphologies. The head capsule for a particular individual was then associated with a corresponding Hb protein profile generated from sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Distinct Hb profiles were observed from one group (Thienemannimyia) and four genera (Chironomus, Cricotopus, Dicrotendipes, and Glyptotendipes) of chironomids. Several species were polymorphic, having more than one Hb profile and/or having bands of the same size as those of other species. However, major bands and the combination of bands could distinguish individuals at the genus and sometimes species-level. Overall, this study showed that Hb profiles can be used in combination with head capsule morphology to identify wild chironomids.

From the ECM to the cytoskeleton and back: how integrins orchestrate T cell action.

T lymphocytes constitute a highly dynamic tissue type. During the course of their lives, they travel through a variety of physiological environments and experience a multitude of interactions with extracellular matrix components and other cells. In order to do this, they must receive many environmental cues, and translate these signals into the appropriate biological actions. Particularly dramatic are the cytoskeletal shape changes a T cell must undergo during the processes of leaving the bloodstream, migrating through tissues, and encountering antigen. In this review, we highlight the role of integrins in providing a link between the extracellular environment and cytoskeletal regulation and how these receptors help to orchestrate T cell migration and antigen recognition.

Regulation of beta 1 integrin-mediated adhesion by T cell receptor signaling involves ZAP-70 but differs from signaling events that regulate transcriptional activity.

Stimulation of the CD3/TCR results within minutes in an increase in T cell adhesion mediated by beta(1) integrins. The biochemical pathways that control CD3-mediated increases in beta(1) integrin-mediated adhesion remain poorly characterized. In this study, the role of the tyrosine kinase ZAP-70 in the regulation of beta(1) integrin activity by the CD3/TCR was investigated. CD3 stimulation did not increase beta(1) integrin-mediated adhesion of the ZAP-70-deficient Jurkat T cell line, P116, to the beta(1) integrin ligand fibronectin. Reintroduction of wild-type ZAP-70, but not a kinase-inactive variant, K369R, corrected the adhesive defect observed in P116 T cells. In addition, the kinase-inactive ZAP-70 mutant inhibited CD3-induced adhesion of primary human T cell blasts. Interestingly, a ZAP-70 mutant with a tyrosine to phenylalanine substitution at position 319 (Y319F) restored the adhesive defect in P116 T cells, even though Y319F ZAP-70 failed to fully reconstitute CD3-initiated NF-AT-dependent transcription and tyrosine phosphorylation of the LAT adapter protein. Finally, expression of mutants of LAT and the SLP-76 adapter protein that modulate CD3-mediated activation of an NF-AT reporter gene failed to block CD3-induced increases in beta(1) integrin-mediated adhesion. These observations support a model in which the tyrosine kinase activity of ZAP-70 kinase is critical for regulation of beta(1) integrin activity by CD3/TCR. However, the signaling events downstream of ZAP-70 that regulate CD3/TCR-mediated activation of beta(1) integrin function exhibit key differences when compared with the signaling pathways that regulate transcriptional events initiated by CD3/TCR stimulation.

The distribution of dermal tumorigens in coal liquids: relationship of tumorigenicity and microbial mutagenicity.

Polycyclic aromatic hydrocarbons and/or their pyrolle derivatives were found to be the primary contributors to the skin tumorigenicity of the neutral fractions of two coal oils. Mutagenicity of the neutral fraction in Salmonella test strains was found to be due primarily to polycyclic aromatics containing polar substituents. Thus, the chemical classes responsible for skin tumorigenicity differ from those responsible for mutagenicity.

Effects of genotype and age on mixed-function oxidase activities in adult Drosophila melanogaster.

The mixed-function oxidases that metabolize dimethylnitrosamine, aminopyrine, benzphetamine, 7-ethoxycoumarin and benzo[alpha]pyrene were measured in adults of the Canton-S, Oregon-R and Hikone-R strains of Drosophila melanogaster. The expression of these activities is both genotype and age dependent.

Studies on the relationship between dimethylnitrosamine-demethylase activity and dimethylnitrosamine-dependent mutagenesis in Drosophila melanogaster.

The relationship between dimethylnitrosamine (DMN) demethylase activity and DMN-induced mutagenesis was investigated in Drosophila melanogaster. The activity of DMN-demethylase was at least 10-fold greater in the Hikone-R strain than in three other Drosophila strains. However, the sex-linked recessive lethal (SLRL) mutations induced by DMN in the four strains differed by less than 2-fold. Several possibilities to explain the lack of correlation between DMN-demethylase activity and DMN-induced mutations were tested and eliminated. They include: (i) the presence of inhibitors of DMN-demethylase in extracts of low-activity strains, (ii) a sex bias in the Hikone-R strain in which the enzyme activity is confined to the females, (iii) the possibility that DMN treatment induces DMN-demethylase activity in the low-activity strains and (iv) the possibility that Hikone-R has a much more efficient DNA repair system than the other strains. The results are discussed in terms of what is known about the role of DMN-demethylase in the metabolic activation of DMN in other systems.

Preparation of oils for bacterial mutagenicity testing.

4 procedures used to prepare fossil-derived oils for bacterial mutagenicity testing have been examined. These are, (a) dewaxing by partitioning the oil between dimethyl sulfoxide (DMSO) and cyclohexane, (b) incorporating a surfactant to increase compatibility of the oil with the bioassay media, (c) directly slurrying the oil in DMSO, and (d) computing the mutagenicity of the oil by summing the contributions of individual chemical class fractions. DMSO slurries generally exhibit higher mutagenicities than computed by summing the contributions of chemical class fractions. Results of testing DMSO-slurries correlate (r = 0.87) well, however, with those obtained by summation. Mutagenicity results agree within a factor of two for the samples tested by 4 sample preparation procedures.

Enhancement of mutagenic activity in Salmonella by contraceptive steroids.

Two oral contraceptive steroids, mestranol and norethynodrel, were evaluated for mutagenicity in the Salmonella histidine reversion assay. The pure forms of the hormones were not mutagenic when tested with either missense (TA1535, TA100) or frameshift (TA98, TA1538, TA1537) strains. In vitro activation of the hormones with liver homogenates from rats induced either with phenobarbital or Aroclor did not influence these results. However, mestranol was capable of enhancing the mutation yield obtained by an ineffective subthreshold dose of 2-acetylaminofluorene. Dimethyl sulfoxide extracts of two contraceptive pills, Ovulen-21 (containing mestranol) or Enovid-E (containing mestranol or norethynodrel), also were nonmutagenic. But again, both these extracts were capable of enhancing the mutation yield induced with an ineffective dosage of 2-acetylaminofluorene and N-nitrosopiperidine. These studies point to the possible promotional effect and subsequent potential hazard to the female consumers who use these hormones as a means of pregnancy control.

Mutagenicity of 4,4'-methylenedianiline derivatives in the Salmonella histidine reversion assay.

4,4'-Methylenedianiline and its derivatives were assayed for mutagenicity in the Salmonella/microsomal mutagenicity assay develop by Ames. A specificity to revert strain TA98 suggests a mechanism of frameshift mutagenesis. Liver microsomal preparations (S-9) from rats induced with phenobarbital were most effective for metabolic activation. Alkyl substitution of 4,4'-methylenedianiline did not alter its mutagenic activity; however, substitution of both positions ortho to the amino group eliminated mutagenic activity. Substitution with alkoxy-carbonyl groups eliminated mutagenic activity, whereas halogen substitution (chlorine, fluorine) enhanced the mutagenic activity. The results presented here show the use of structure-activity studies as predictive tools for the assessment of genotoxic properties of industrial chemicals.

Structure activity studies with N-nitrosamines using Salmonella typhimurium and Escherichia coli.

Mutagenic activities of a large number of nitrosamines were determined using Salmonella histidine reversion and Escherichia coli arginine reversion assays. The cyclic nitrosamines exhibited a close correlation between their mutagenic and carcinogenic properties, while no such relationship was evident with the aliphatic nitrosamines. Substitution of cyclic nitrosamines with methyl, hydroxy and oxy groups did not alter the mutagenic activities. However, when positions alpha to the N-nitroso groups were substituted with methyl groups, the biological activity was eliminated. Substitution with halogens enhanced, whereas carboxyl substitution eliminated the biological activity. The E. coli assay not only substantiated the observations made with Salmonella, but also demonstrated mutagenic activity in the case of certain carcinogenic nitrosamines which were not mutagenic in the Salmonella assay.

Analytical and biological analysis of test materials from the synthetic fuel technologies.

Nitrogen-containing organic compounds from environmental sources are receiving increasing attention because of uniquely active mutagens which have been found in this class (Chrisp et al., 1978; Nagao and Sugimura, 1978: Guerin et al., 1980) Differences in mutagenic activities among the various organo-nitrogen compounds, i.e., pyrrole types, pyridine types and aniline types, have been noted consistently. Furthermore, differences among homologs of a particular compound type are often striking. Information in this paper engages the question of chemical structure/biological activity relationships. Activity data for several N-heterocyclic, nitro-, amino- (primary, secondary and tertiary), and amino-N-heterocyclic aromatic compounds are presented. The number of fused rings and the substituent type affect the mutagenic activities greatly. The trends observed are discussed generally with reference to molecular structural features.

Nitrosamine-induced mutagenesis in Escherichia coli K12 (343/113). 1. Mutagenic properties of certain aliphatic nitrosamines.

The Escherichia coli K12 (343/113) test system developed by G. Mohn was used to detect the mutagenic activity induced by a group of aliphatic nitrosamines. Metabolic activation was incorporated into the assay by the addition of liver homogenates induced in either Sprague-Dawley rats or C3H mice with the addition of 0.1% phenobarbital to the drinking water. Nitrosodiethylamine (NDEA) was mutagenic upon metabolic activation and exhibited a preference to revert the missense mutation at the arginine locus. NDEA was also capable of inducing the forward mutation, selected as an ability to utilize galactose. NDEA was converted effectively into a mutagen in a time period of 30 min to 2 h. Metabolic activation with the mouse and rat liver preparations did not result in quantitative differences. Aliphatic nitrosamines that gave unexpected results with the Salmonella assay [4-10] were examined in the E. coli system. Nitrosodipropylamine (NDPA) and nitrosodiallylamine (NDAA) were mutagenic in both E. coli and Salmonella. Nitrosomethylethylamine (NMEA) was not mutagenic in Salmonella but was mutagenic in E. coli, and a strong carcinogen, nitrosomethylneopentylamine (NMNA), was not mutagenic in either assay. These results indicate the use of multiple genetic assays for the detection of genotoxic chemicals in our environment.

Mutagenicity of N-nitrosopyrrolidine derivatives in Salmonella (Ames) and Escherichia coli K-12 (343/113) assays.

The mutagenicity of nitrosopyrrolidine (NPYR) and its derivatives was determined by use of the Ames Salmonella assay. A clear specificity to revert the missense stain of TA1535 and a requirement for the phenobarbital-induced rat-liver activation system (S9 mix) were noted. 3,4-Dichloronitrosopyrrolidine was more mutagenic than NPYR, whereas 3-hydroxynitrosopyrrolidine was weakly mutagenic. The carcinogenic nitroso-3-pyrrolidine was not mutagenic under the test conditions. The noncarcinogenic derivatives (2,5-dimethylnitrosopyrrolidine, nitrosoproline and 4-hydroxynitrosoproline) were not mutagenic. Liquid preincubation assays were not any more effective than the pour-plate assays. Selected derivatives of NPYR were tested in the Escherichia coli K-12 (343/113) assay A specificity to revert the missense mutation at the arg locus and a dependence on phenobarbital-induced rat-liver S9 mix were noted with NPYR and its derivatives. 3,4-Dibromonitrosopyrrolidine, which was not mutagenic in Salmonella, was effective in E. coli, and the weakly carcinogenic NPRL was a weak mutagen resulting in a 2-fold enhancement in the E. coli arginine reversion assay.