SCENEDESMUS MORPHOLOGY AND FLOTATION1

Various flotation studies were conducted on several strains of Scenedesmus. Inverted microscope flotation experiments run on culture 614 with bristles, culture 614 centrifuged to remove bristles, and bristle-less strain 76 revealed that bristles aid in flotation. Cultures grown in NH₄NO₃-Bristol's compared to cultures grown in Bristol's medium exhibited a positive buoyancy as do cells transferred, to fresh media. Differential centrifugation procedures demonstrate that colonies with bristles and spines exhibit a greater buoyancy than spineless and bristle less colonies, and furthermore that unicells and newly released colonies exhibit greater buoyancy than older cultures and large, granular, dividing cells.     

Transcription of the chicken histone H5 gene is mediated by distinct tissue-specific elements within the promoter and the 3'' enhancer.

Molecular genetic analysis of a number of vertebrate erythroid cell-specific genes has identified at least two types of cis-acting regulatory sequences which control the complex developmental pattern of gene expression during erythroid cell maturation. Tissue-specific cellular enhancers have been identified 3' to three erythroid cell-specific genes, and additional regulatory elements have been identified in the promoters of many erythroid genes. We show that the histone H5 enhancer, like the adult beta-globin enhancer, is involved in mediating the developmental induction of histone H5 mRNA as erythroid cells mature. We also describe the preliminary characterization of a tissue-specific regulatory element within the 5' region of the H5 locus and describe investigations of the interaction between this element and the histone H5 enhancer in mediating histone H5 regulation.     

Analysis of Carnosine, Homocarnosine, and Other Histidyl Derivatives in Rat Brain

Isocratic reverse-phase analytical HPLC has been used to examine naturally occurring imidazoles of rat brain. Elution of brain extracts with a phosphate buffer mobile phase from columns packed with Hypersil ODS (5 microns) resulted in good separation of the well-documented brain imidazole-containing dipeptides carnosine and homocarnosine. Measured concentrations corresponded to published values. Several further peaks observed had properties consistent with those of N-acetyl derivatives of compounds related to carnosine and homocarnosine. N-Acetyl forms not commercially available were prepared and their identities verified by nuclear magnetic resonance spectroscopy. A number of these had chromatographic properties identical to those of compounds in brain extracts. Fractions corresponding to some of the peaks were examined using staining systems specific for certain chemical features and compared with results obtained for commercial or synthetic standards. The results of these tests supported the chromatographic data. Thus, chromatographic and microchemical evidence is presented for the existence of N-acetyl forms of histidine, 1-methylhistidine, carnosine, anserine, and homocarnosine in rat brain.     

Thiazolo[4,5-d]pyrimidine thiones and -ones as corticotropin-releasing hormone (CRH-R1) receptor antagonists.

A series of thiazolo[4,5-d]pyrimidine thiones and -ones was prepared and discovered to have good binding affinity to the CRH-R1 receptor, thus showing promise as a new class of potential anxiolytics and/or antidepressants.     

Synthesis and evaluation of indenopyrazoles as cyclin-dependent kinase inhibitors. Part 4: Heterocycles at C3

New indeno[1,2-c]pyrazol-4-one cyclin dependent kinase inhibitors have been disclosed. The most promising compounds are nanomolar enzyme inhibitors with excellent activity against tumor cells. The most advanced compound retains cell culture activity even in the presence of human serum proteins. The most advanced compound did not kill the normal fibroblast line AG1523.     

SCENEDESMUS MORPHOGENESIS. TRACE ELEMENTS AND SPINE FORMATION1

When Scenedesmus culture 16, a soil organism with numerous long spines, was grown in axenic culture in a dilute laboratory medium (with approximately 30 mg/liter total salts), spines were not formed. In this medium the organism resembled S. bijugatus, whereas S. longus and S. abundans colonies were typically formed in more concentrated media. Spines were formed on daughter colonies upon transfer to the dilute medium plus additional Fe EDTA or Ca EDTA. No other individual components of the medium did this. Spineless colonies were healthy and green with a well-defined chloroplast, provided the culture was transferred often. In addition to the absence of spines, cultures in the dilute medium had a linear arrangement of cells within a colony, along with terminal cells 20% shorter than median cells. With 4-celled spiny colonies all cells were the same length and were alternately arranged.     

Identification and optimization of small molecule antagonists of vasoactive intestinal peptide receptor-1 (VIPR1)

Identification, synthesis and structure-activity relationship of small-molecule VIPR1 antagonists encompassing two chemical series are described.     

Individual differences in estrogen receptor alpha in select brain nuclei are associated with individual differences in aggression

Steroid hormones play an important role in modulating social behavior in many species. Estrogens are thought to act on an interconnected network of hypothalamic and limbic brain areas to affect aggressive behavior, although the specific nuclei unknown remain unspecified. We show that individual variation in estrogen receptor alpha (ERalpha) immunoreactivity in the lateral septum (LS), ventral bed nucleus of the stria terminalis (vBNST), and anterior hypothalamus (AHA) of CD-1 mice is positively correlated with aggressive behavior. When males were treated with fadrozole (an aromatase inhibitor), aggressive behavior was reduced, although castration did not reduce aggression. These results suggest that estrogens modulate aggressive behavior by acting on a circuit that includes the LS, vBNST, and AHA and that the source of estrogens is non-gonadal. Fadrozole also decreased c-fos expression in the lateral septum following aggressive encounters. Although the effects of estrogen on aggression appear to involve regulation of neuronal activity in the LS, additional processes are likely involved. These results suggest that estrogen acts in a specific subset of a complex network of nuclei to affect aggressive behavior.