[Evaluation and fate of the organic chlorine pesticides at the waters in Jiulong River Estuary]

18 Organochlorine Pesticides at the water(surface water and porewater) in Jiulong River Estuary were determined. The range of organochlorine pesticides at surface water was 51.3-2479 ng/L, and the concentration in porewater was 266-33,355 ng/L. The results showed that the organochlorine pesticides were removed in the estuary and the sediments were the reservior of the organochlorine pesticides. Compared with the results of other harbor and estuaries, it showed that the contamination for organic chlorine pollutants in Jiulong River Estuary was similar to those of others. At the same time, the risk of organochlorine pesticides in the estuary was evaluated.

X-ray studies of phonon softening in tise2

The charge-density-wave transition in TiSe (2), which results in a commensurate (2x2x2) superlattice at temperatures below approximately 200 K, presumably involves softening of a zone-boundary phonon mode. For the first time, this phonon-softening behavior has been examined over a wide temperature range by synchrotron x-ray thermal diffuse scattering.

[Effect of recombinant epidermal growth factor on corneal epithelial cells after excision of pterygium]

OBJECTIVE

To investigate the effects of recombinant epidermal growth factor on the wounded corneal healing after excision of pterygium.

METHODS

Simple and unrecurrent pterygium was selected, excised and sewed up conjunctival flap under local anaesthesia and microscope. After operation two drops of EGF eyedrop were used, and five minutes later 0.3% Tarivid Eye Oint was used again, and then the operated eye was enswathed. Everyday the wound cornea was observed and the EGF eyedrop was used.

RESULTS

The wound cornea healing time of control group was seven days and that of the EGF group was five days and gave a remarkable difference (P < 0.05). The same results were obtained after comparing the effective group and ineffective group, P < 0.05.

CONCLUSIONS

EGF eyedrop can accelerate proliferation and recovery of wound corneal epithelial cells. In the clinical trial, every body felt well and no side-effect was observed.

Identification and analysis of a gene from Calendula officinalis encoding a fatty acid conjugase

Two homologous cDNAs, CoFad2 and CoFac2, were isolated from a Calendula officinalis developing seed by a polymerase chain reaction-based cloning strategy. Both sequences share similarity to FAD2 desaturases and FAD2-related enzymes. In C. officinalis plants CoFad2 was expressed in all tissues tested, whereas CoFac2 expression was specific to developing seeds. Expression of CoFad2 cDNA in yeast (Saccharomyces cerevisiae) indicated it encodes a Delta12 desaturase that introduces a double bond at the 12 position of 16:1(9Z) and 18:1(9Z). Expression of CoFac2 in yeast revealed that the encoded enzyme acts as a fatty acid conjugase converting 18:2(9Z, 12Z) to calendic acid 18:3(8E, 10E, 12Z). The enzyme also has weak activity on the mono-unsaturates 16:1(9Z) and 18:1(9Z) producing compounds with the properties of 8,10 conjugated dienes.

Molecular oxygen spin-lattice relaxation in solutions measured by proton magnetic relaxation dispersion

Proton spin-lattice relaxation rate constants have been measured as a function of magnetic field strength for water, water-glycerol solution, cyclohexane, methanol, benzene, acetone, acetonitrile, and dimethyl sulfoxide. The magnetic relaxation dispersion is well approximated by a Lorentzian shape. The origin of the relaxation dispersion is identified with the paramagnetic contribution from molecular oxygen. In the small molecule cases studied here, the effective correlation time for the electron-nuclear coupling may include contributions from both translational diffusion and the electron T(1). The electron T(1) for molecular oxygen dissolved in several solvents was found to be approximately 7.5 ps and nearly independent of solvent or viscosity.

Phase synchronization and noise-induced resonance in systems of coupled oscillators

We study synchronization and noise-induced resonance phenomena in systems of globally coupled oscillators, each possessing finite inertia. The behavior of the order parameter, which measures the collective synchronization of the system, is investigated as the noise level and the coupling strength are varied, and hysteretic behavior is manifested. The power spectrum of the phase velocity is also examined and the quality factor as well as the response function is obtained to reveal noise-induced resonance behavior.

Association of SPARC (osteonectin, BM-40) with extracellular and intracellular components of the ciliated surface ectoderm of Xenopus embryos

SPARC (Secreted Protein, Acidic, Rich in Cysteine) was detected by immunohistochemistry in the sensorial layer of the bilayered embryonic epidermis of Xenopus laevis during neurulation, when a subset of the sensorial cells are selected to differentiate into ciliated cell precursors. After the ciliated cells had intercalated into the outer layer and had undergone ciliogenesis, intense SPARC immunostaining was associated with the cilia and remained associated with the cilia throughout their persistence on the epidermis. Circumferential SPARC immunostaining was also detected at the interface between surface epithelial cells. Animal cap explants indicated that the embryonic activation of SPARC expression in the dorsal ectoderm does not require signaling from factors secreted by the underlying mesoderm. Immunoelectron microscopy revealed that SPARC is intimately associated with the 9 + 2 microtubule arrays of cilia. Our data indicate that SPARC plays a role in the development and function of the surface ciliated epidermis of Xenopus embryos. We propose that the counter-adhesive activity of SPARC facilitates the intercalation of ciliary cell precursors to the surface epithelial layer, where its Ca(2+)-binding abilities promote cell-cell adhesion. Based on its association with ciliary microtubule arrays, we also propose that intracellular SPARC may play a role in regulating ciliary beat frequency and polarity.

NMR studies on novel antitumor drug candidates, deoxoartemisinin and carboxypropyldeoxoartemisinin

Artemisinin and its derivatives, which have been known as antimalarial drugs, have also demonstrated their cytotoxicity against tumor cells. It has been proposed that antitumor activity depends on the lipophilicity of functional group on artemisinin derivatives. Solution structures of two artemisinin derivatives as antitumor drug candidates, deoxoartemisinin and carboxypropyldeoxoartemisinin, were determined by NMR spectroscopy to elucidate structure-activity relationship. According to biological assay, antitumor efficiencies are not dependent upon lipophilicity. Instead, these compounds demonstrated their distinctive structural features of boat/chair conformation and capability to interact with receptors, as they have different efficiencies on antitumor activity. Especially, carboxypropyl moiety or carbonyl moiety in artemisinin derivatives influences the conformation and stability of ring structure. Although the detailed mechanism of antitumor activity by artemisinin derivatives has not been addressed, we suggest that antitumor activity is not determined only with lipophilicity and that artemisinin derivatives have specific target proteins in each type of cancer.

Protective effect of etomidate on kainic acid-induced neurotoxicity in rat hippocampus

The goal of this study was to determine whether etomidate has protective effect against kainic acid (KA)-induced neurotoxicity. Administration of etomidate (20 mg/kg i.p.) was performed in sequence, first being just 1 h after KA (10 mg/kg i.p.) injection, then three times at 1-h intervals. Neuronal damages in hippocampus were evaluated by using the acid fuchsin stain to detect cell death and the heat shock protein-70 (HSP-70) induction as an index of cell injury at 24 h after the administration of KA. HSP-70 induction and acid fuchsin positive neurons were increased in CA1 and CA3 regions of hippocampus after KA injection but significantly decreased by etomidate-injection. These results suggest that the etomidate hold potential effect on the protection of neurons against KA-induced neurotoxicity.

Interaction of the tau2 transcriptional activation domain of glucocorticoid receptor with a novel steroid receptor coactivator, Hic-5, which localizes to both focal adhesions and the nuclear matrix

Hic-5 (hydrogen peroxide-inducible clone-5) is a focal adhesion protein that is involved in cellular senescence. In the present study, a yeast two-hybrid screen identified Hic-5 as a protein that interacts with a region of the glucocorticoid receptor that includes a nuclear matrix-targeting signal and the tau2 transcriptional activation domain. In transiently transfected mammalian cells, overexpression of Hic-5 potentiated the activation of reporter genes by all steroid receptors, excluding the estrogen receptor. The activity of the estrogen receptor and the thyroid hormone receptor was stimulated by Hic-5 in the presence but not in the absence of coexpressed coactivator GRIP1. In biochemical fractionations and indirect immunofluorescence assays, a fraction of endogenous Hic-5 in REF-52 cells and transiently expressed Hic-5 in Cos-1 cells was associated with the nuclear matrix. The C-terminal region of Hic-5, which contains seven zinc fingers arranged in four LIM domains, was required for interaction with focal adhesions, the nuclear matrix, steroid receptors, and the tau2 domain of glucocorticoid receptor. The N-terminal region of Hic-5 possesses a transcriptional activation domain and was essential for the coactivator activity of Hic-5. Given the coexisting cytoplasmic and nuclear distributions of Hic-5 and its role in steroid receptor-mediated transcriptional activation, it is proposed that Hic-5 might transmit signals that emanate at cell attachment sites and regulate transcription factors, such as steroid receptors.

Intraerythrocytic development of species of Hepatozoon infecting ranid frogs: evidence for convergence of life cycle characteristics among apicomplexans

Intraerythrocytic development of the adeleorin apicomplexans Hepatozoon clamatae and Hepatozoon catesbianae were investigated in the bullfrog, Rana catesbeiana, the green frog, Rana clamitans melanota, and the Northern leopard frog, Rana pipiens. Merozoites emerging from hepatic meronts penetrated erythrocytes and underwent 1-3 rounds of binary fission to produce 2-8 merozoites. Following their release from infected erythrocytes, individual merozoites entered new cells and transformed into gamonts. Although this is the first report of intraerythrocytic development for a fully described species of Hepatozoon, a phylogenetic reanalysis of 11 species of Hepatozoon, 6 species representative of the 5 other hemogregarine taxa, 2 species of dactylosomatids, and 2 species of piroplasms, indicates that asexual reproduction of parasites within blood cells of vertebrates has arisen at least 3 times in the apicomplexan lineage that includes adeleorins and piroplasms. This method of asexual development, which is also observed in species of hemospororin genera such as Plasmodium, is discussed in the context of the evolution of apicomplexan life cycles. In addition to supporting the paraphyly of the genus Hepatozoon determined in an earlier study, this phylogenetic analysis featured a monophyletic group, consisting of the sister taxa Hemolivia and Karyolysus, that was the sister group to a clade consisting of the more derived hemogregarines, the dactylosomatids, and the piroplasms.

The formation of PHF-1 and SMI-31 positive dystrophic neurites in rat hippocampus following acute injection of okadaic acid

Within neurofibrillary tangles and dystrophic neurites of Alzheimer's disease (AD), tau protein is hyperphosphorylated. In the present study, we provide evidence that acute injection of okadaic acid (1 mM, 0.5 microliter) into the dorsal hippocampus induces the formation of paired helical filament (PHF)-1, sternberger monoclonals incorporated (SMI)-31, and amyloid precursor protein (APP) positive dystrophic neurites in the lacunosum-molecular layer of CA1 and molecular layer of dentate gyrus. Okadaic acid evoked a marked loss of microtubule associated protein (MAP)-2 immunoreactivity. PHF-1 immunoreactive terminals were fine, and SMI-31 immunoreactive terminals appeared at granular terminals and at the ring-like or elongated dystrophic neurites. APP positive dystrophic neurites exhibited large bulb-like globular terminals. Interestingly, APP dystrophic neurites were co-localized with SMI-31 immunoreactivity in the core. APP immunoreactivity became stronger over 24 h even in vehicle injected area. These results may provide the morphological evidence for the animal model to study dystrophic neurites formation of AD.

[3D models for diagnosis and treatment planning in cardiology]

Due to the development new of imaging devices which produce a large number of tomographic slices, advanced techniques for the evaluation of the large amount of data are required. Computer supported extraction of dynamic 3D-models of the patients anatomy from temporal series thus is highly desirable. Since the diagnostician should be able to quickly make sensible decisions based on the models, high accuracy is required within a minimum of time. We present modeling and visualization techniques that are realized within the Cardiac Station. Results for the application of these techniques to cardiac image data demonstrate their usability. Besides giving information about the patients morphology functional parameters can be derived from the data and visualized together with the model. In order to verify the model with the original image data and for the planning of real intervention interaction techniques are presented.

Synchronization in a system of globally coupled oscillators with time delay

We study the synchronization phenomena in a system of globally coupled oscillators with time delay in the coupling. The self-consistency equations for the order parameter are derived, which depend explicitly on the amount of delay. Analysis of these equations reveals that the system in general exhibits discontinuous transitions in addition to the usual continuous transition, between the incoherent state and a multitude of coherent states with different synchronization frequencies. In particular, the phase diagram is obtained on the plane of the coupling strength and the delay time, and ubiquity of multistability as well as suppression of the synchronization frequency is manifested. Numerical simulations are also performed to give consistent results.

Constitutive activation of transcription and binding of coactivator by estrogen-related receptors 1 and 2

In this report, we demonstrate that, in contrast to most previously characterized nuclear receptors, hERR1 and hERR2 (human estrogen receptor-related protein 1 and -2) are constitutive activators of the classic estrogen response element (ERE) as well as the palindromic thyroid hormone response element (TRE(pal)) but not the glucocorticoid response element (GRE). This intrinsically activated state of hERR1 and hERR2 resides in the ligand-binding domains of the two genes and is transferable to a heterologous receptor. In addition, we show that members of the p160 family of nuclear receptor coactivators, ACTR (activator of thyroid and retinoic acid receptors), GRIP1 (glucocorticoid receptor interacting protein 1), and SRC-1 (steroid receptor coactivator 1), potentiate the transcriptional activity by hERR1 and hERR2 in mammalian cells, and that both orphan receptors bind the coactivators in a ligand-independent manner. Together, these results suggest that hERR1 and hERR2 activate gene transcription through a mechanism different from most of the previously characterized steroid hormone receptors.

Synchronization and resonance in a driven system of coupled oscillators

We study the noise effects in a driven system of globally coupled oscillators, with particular attention to the interplay between driving and noise. The self-consistency equation for the order parameter, which measures the collective synchronization of the system, is derived; it is found that the total order parameter decreases monotonically with noise, indicating overall suppression of synchronization. Still, for large coupling strengths, there exists an optimal noise level at which the periodic (ac) component of the order parameter reaches its maximum. The response of the phase velocity is also examined and found to display resonance behavior.

Multiple signal input and output domains of the 160-kilodalton nuclear receptor coactivator proteins

Members of the 160-kDa nuclear receptor coactivator family (p160 coactivators) bind to the conserved AF-2 activation function found in the hormone binding domains of nuclear receptors (NR) and are potent transcriptional coactivators for NRs. Here we report that the C-terminal region of p160 coactivators glucocorticoid receptor interacting protein 1 (GRIP1), steroid receptor coactivator 1 (SRC-1a), and SRC-1e binds the N-terminal AF-1 activation function of the androgen receptor (AR), and p160 coactivators can thereby enhance transcriptional activation by AR. While they all interact efficiently with AR AF-1, these same coactivators have vastly different binding strengths with and coactivator effects on AR AF-2. p160 activation domain AD1, which binds secondary coactivators CREB binding protein (CBP) and p300, was previously implicated as the principal domain for transmitting the activating signal to the transcription machinery. We identified a new highly conserved motif in the AD1 region which is important for CBP/p300 binding. Deletion of AD1 only partially reduced p160 coactivator function, due to signaling through AD2, another activation domain located at the C-terminal end of p160 coactivators. C-terminal coactivator fragments lacking AD1 but containing AD2 and the AR AF-1 binding site served as efficient coactivators for full-length AR and AR AF-1. The two signal input domains (one that binds NR AF-2 domains and one that binds AF-1 domains of some but not all NRs) and the two signal output domains (AD1 and AD2) of p160 coactivators played different relative roles for two different NRs: AR and thyroid hormone receptor.

Hormone-independent transcriptional activation and coactivator binding by novel orphan nuclear receptor ERR3

Orphan nuclear receptors share sequence homology with members of the nuclear receptor superfamily, but ligands are unknown or unnecessary. A novel orphan receptor, estrogen receptor-related protein 3 (ERR3), was identified by yeast two-hybrid screening, using the transcriptional coactivator glucocorticoid receptor interacting protein 1 (GRIP1) as bait. The putative full-length mouse ERR3 contains 458 amino acids and is closely related to two known orphan receptors ERR1 and ERR2. All the ERR family members share an almost identical DNA-binding domain, which has 68% amino acid identity with that of estrogen receptor. ERR3 bound specifically to an estrogen response element and activated reporter genes controlled by estrogen response elements, both in yeast and in mammalian cells, in the absence of any added ligand. A conserved AF-2 activation domain located in the hormone-binding domain of ERR3 was primarily responsible for transcriptional activation. The ERR3 AF-2 domain bound GRIP1 in a ligand-independent manner both in vitro and in vivo, through the LXXLL motifs of GRIP1, and GRIP1 functioned as a transcriptional coactivator for ERR3 in both yeast and mammalian cells. Expression of ERR3 in adult mouse was restricted; highest expression was observed in heart, kidney, and brain. In the mouse embryo no expression was observed at day 7, and highest expression occurred around the 11-15 day stages. Although ERR3 is much more closely related to ERR2 than to ERR1, the expression pattern for ERR3 was similar to that of ERR1 and distinct from that for ERR2, suggesting a unique role for ERR3 in development.

Detection of breast lesions by holographic interferometry

The holographic interferometry (HI) technique commonly used for nondestructive testing of laminate materials was applied to create fringe contour distortion near the site of indwelling breast lesions. For this medical imaging application, the HI technique was successful in demonstrating abnormal mechanical properties of living tissue. Adequate density and contrast of fringes, crucial factors necessary for analysis of surface deformation of an object, can be made only with an appropriate stressing method. We have applied vibration and mild pressure to the surface of female breasts for the purpose of detecting localized densities and mass alterations of the tissue, which may be indicative of an abnormality of that tissue. Even though each stressing method had both positive and negative aspects, pneumatic pressure was adopted for the present study because it was more suitable for a noninvasive and noncontact breast examination. We also developed a computer based holographic imaging system to precisely control the stressing phase for the pressure and laser triggering so the resultant holograms had manageable fringe density and repeatability. © 1999 Society of Photo-Optical Instrumentation Engineers.

Regulation of transcription by a protein methyltransferase

The p160 family of coactivators, SRC-1, GRIP1/TIF2, and p/CIP, mediate transcriptional activation by nuclear hormone receptors. Coactivator-associated arginine methyltransferase 1 (CARM1), a previously unidentified protein that binds to the carboxyl-terminal region of p160 coactivators, enhanced transcriptional activation by nuclear receptors, but only when GRIP1 or SRC-1a was coexpressed. Thus, CARM1 functions as a secondary coactivator through its association with p160 coactivators. CARM1 can methylate histone H3 in vitro, and a mutation in the putative S-adenosylmethionine binding domain of CARM1 substantially reduced both methyltransferase and coactivator activities. Thus, coactivator-mediated methylation of proteins in the transcription machinery may contribute to transcriptional regulation.

Prenatal fragile X detection using cytoplasmic and nuclear-specific monoclonal antibodies

We have been carrying out studies aimed at improving prenatal detection of the fragile X chromosome/mutation. Our current protocol requires a turnaround time (TAT) of several days. In an attempt to reduce the TAT, we have turned to the use of monoclonal antibodies (mAbs). Monoclonal antibody 1A1 (provided by Dr. Mandel of INSERM) immunostaining was performed according to a modified three-step immunocytochemical procedure. We found that cytoplasmic staining intensities, using mAb 1A1/avidin biotinylated complex/diaminobenzidine, varied from light to heavy within each sample, with controls exhibiting a majority of heavily stained cells in both chorionic villus (CV) sample and amniotic fluid cultured cells. Using mAb 1A1 and a new nuclear-specific antibody, mAb 3F11, we found that CV cultured cells harboring the FMR1 full mutation could be distinguished from controls as early as 10 weeks of gestation in both male and female specimens. Western blot analysis showed that the antibodies have similar staining patterns but that mAb 3F11 has fewer background/nonspecific bands. Our results demonstrate that it is feasible to detect fragile X full mutations within one day after obtaining cells from CV specimens taken as early as 10 weeks of gestation.

An additional region of coactivator GRIP1 required for interaction with the hormone-binding domains of a subset of nuclear receptors

Transcriptional coactivators of the p160 family (SRC-1, GRIP1, and p/CIP) associate with DNA-bound nuclear receptors (NRs) and help the NRs to recruit an active transcription initiation complex to the promoters of target genes. Previous studies have demonstrated the importance of the NR interaction domain (NID) of p160 proteins containing three NR box motifs (LXXLL) for the interaction with the hormone-binding domains of NRs. Here we report that, in addition to NID, another region of coactivator GRIP1 (amino acids 1011-1121), called the auxiliary NID (NIDaux), is required in vitro and in vivo for efficient interaction with a subset of NRs, including the glucocorticoid receptor (GR), androgen receptor, and retinoic acid receptor alpha. A second group of NRs, which includes the progesterone receptor, retinoid X receptor alpha, thyroid hormone receptor beta1, and vitamin D receptor, required only NID for efficient interaction. For binding to GR, the NID and NIDaux of GRIP1 must act in cis, but deletion of up to 144 amino acids between the two regions did not reduce binding efficiency. Amino acids 1011-1121 of GRIP1 also contain a p300 interaction domain, but mutational analysis indicated that the p300 interaction function within this region is separable from the ability to contribute to GR hormone-binding domain binding. SRC-1 lacks an NIDaux activity equivalent to that in GRIP1.

Dynamic equilibrium unfolding pathway of human tumor necrosis factor-alpha induced by guanidine hydrochloride

The dynamic equilibrium unfolding pathway of human tumor necrosis factor-alpha (TNF-alpha) during denaturation at different guanidine hydrochloride (GdnHCl) concentrations (0-4.2 M) was investigated by steady-state fluorescence spectroscopy, potassium iodide (KI) fluorescence quenching, far-UV circular dichroism (CD), picosecond time-resolved fluorescence lifetime, and anisotropy decay measurements. We utilized the intrinsic fluorescence of Trp-28 and Trp-114 to characterize the conformational changes involved in the equilibrium unfolding pathway. The detailed unfolding pathway under equilibrium conditions was discussed with respect to motional dynamics and partially folded structures. At 0-0.9 M [GdnHCl], the rotational correlation times of 22-25 ns were obtained from fluorescence anisotropy decay measurements and assigned to those of trimeric states by hydrodynamic calculation. In this range, the solvent accessibility of Trp residues increased with increasing [GdnHCl], suggesting the slight expansion of the trimeric structure. At 1.2-2.1 M [GdnHCl], the enhanced solvent accessibility and the rotational degree of freedom of Trp residues were observed, implying the loosening of the internal structure. In this [GdnHCl] region, TNF-alpha was thought to be in soluble aggregates having distinct conformational characteristics from a native (N) or fully unfolded state (U). At 4.2 M [GdnHCl], TNF-alpha unfolded to a U-state. From these results, the equilibrium unfolding pathway of TNF-alpha, trimeric and all beta-sheet protein, could not be viewed from the simple two state model (N-->U).

Identification of HIV-1 integrase inhibitors based on a four-point pharmacophore

The rapid emergence of human immunodeficiency virus (HIV) strains resistant to available drugs implies that effective treatment modalities will require the use of a combination of drugs targeting different sites of the HIV life cycle. Because the virus cannot replicate without integration into a host chromosome, HIV-1 integrase (IN) is an attractive therapeutic target. Thus, an effective IN inhibitor should provide additional benefit in combination chemotherapy. A four-point pharmacophore has been identified based on the structures of quinalizarin and purpurin, which were found to be potent IN inhibitors using both a preintegration complex assay and a purified enzyme assay in vitro. Searching with this four-point pharmacophore in the 'open' part of the National Cancer Institute three-dimensional structure database produced 234 compounds containing the pharmacophore. Sixty of these compounds were tested for their inhibitory activity against IN using the purified enzyme; 19 were found to be active against IN with IC50 values of less than 100 microM, among which 10 had IC50 values of less than 10 microM. These inhibitors can further serve as leads, and studies are in progress to design novel inhibitors based on the results presented in this study.

Salicylhydrazine-containing inhibitors of HIV-1 integrase: implication for a selective chelation in the integrase active site

In previous studies we identified N,N'-bis(salicylhydrazine) (1) as a lead compound against purified recombinant HIV-1 integrase. We have now expanded upon these earlier observations and tested 45 novel hydrazides. Among the compounds tested, 11 derivatives exhibited 50% inhibitory concentrations (IC50) of less than 3 microM. A common feature for activity among these inhibitors is the hydroxyl group of the salicyl moiety. Although the active inhibitors must contain this hydroxyl group, other structural modifications can also influence potency. Removal of this hydroxyl group or replacement with an amino, bromo, fluoro, carboxylic acid, or ethyl ether totally abolished potency against integrase. Several asymmetric structures exhibited similar potency to the symmetric lead inhibitor 1. The superimposition of the lowest-energy conformations upon one another revealed three sites whose properties appear important for ligand binding. Site A is composed of the 2-hydroxyphenyl, the alpha-keto, and the hydrazine moieties in a planar conformation. We propose that this site could interact with HIV-1 integrase by chelation of the metal in the integrase active site as inhibition of HIV-1 integrase catalytic activity and DNA binding were strictly Mn2+-dependent. The hydrophobic sites B and C are probably responsible for complementarity of molecular shape between ligand and receptor. Our data indicate that only those compounds which possessed sites A, B, and C in a linear orientation were potent inhibitors of HIV-1 integrase. Although all the active inhibitors possessed considerable cytotoxicity and no apparent antiviral activity in CEM cells, the study presents useful information regarding ligand interaction with HIV-1 integrase protein.

Study on acupuncture and moxibustion therapy for female urethral syndrome

Among 180 patients with female urethral syndrome, 128 were treated by acupuncture and moxibustion and 52 by western medicine as controls. The short-term effective rate in the acupuncture and moxibustion group was 90.6% and the long-term effective rate, 80.4%; whereas the short-term effective rate of the control group was 26.9% (P < 0.01). The maximal uroflow rate increased by an average of 4.6 ml/s, after acupuncture and moxibustion treatment (P < 0.001) and the mean uroflow rate increased by an average of 3.1 ml/s (P < 0.001); on the contrary, no changes were found in the control group (P > 0.05). Sixty-nine cases from the acupuncture and moxibustion group and 39 from the control group were subjected before and after treatment to determinations of the maximal bladder pressure, maximal abdominal pressure, bladder-neck pressure, and maximal urethral closure pressure during urination. All these indexes were decreased remarkably in the acupuncture and moxibustion group, while no changes were observed in the control group.

Identification of a nucleotide binding site in HIV-1 integrase

HIV-1 integrase is essential for viral replication and can be inhibited by antiviral nucleotides. Photoaffinity labeling with the 3'-azido-3'-deoxythymidine (AZT) analog 3',5-diazido-2', 3'-dideoxyuridine 5'-monophosphate (5N3-AZTMP) and proteolytic mapping identified the amino acid 153-167 region of integrase as the site of photocrosslinking. Docking of 5N3-AZTMP revealed the possibility for strong hydrogen bonds between the inhibitor and lysines 156, 159, and 160 of the enzyme. Mutation of these residues reduced photocrosslinking selectively. This report elucidates the binding site of a nucleotide inhibitor of HIV-1 integrase, and possibly a component of the enzyme polynucleotide binding site.

Nuclear receptor-binding sites of coactivators glucocorticoid receptor interacting protein 1 (GRIP1) and steroid receptor coactivator 1 (SRC-1): multiple motifs with different binding specificities

The activity of the AF-2 transcriptional activation function of nuclear receptors (NR) is mediated by the partially homologous transcriptional coactivators, glucocorticoid receptor interacting protein 1 (GRIP1)/transcriptional intermediary factor 2 (TIF2) and steroid receptor coactivator 1 (SRC-1). GRIP1 and SRC-1 bound nine different NRs and exhibited similar, but not identical, NR binding preferences. The most striking difference was seen with the androgen receptor, which bound well to GRIP1 but poorly to SRC-1. GRIP1 and SRC-1 contain three copies of the NR binding motif LXXLL (called an NR Box) in their central regions. Mutation of both NR Box II and NR Box III in GRIP1 almost completely eliminated functional and binding interactions with NRs, indicating that these two sites are crucial for most of GRIP1's NR binding activity. Interactions of GRIP1 with the estrogen receptor were more strongly affected by mutations in NR Box II, whereas interactions with the androgen receptor and glucocorticoid receptor were more strongly affected by NR Box III mutations. One isoform of SRC-1 has an additional NR Box (NR Box IV) at its extreme C terminus with an NR-binding preference somewhat different from that of the central NR-binding domain of SRC-1. GRIP1 has no NR Box in its C-terminal region and therefore no C-terminal NR-binding function. In summary, GRIP1 and SRC-1 have overlapping NR-binding preferences, but specific NRs display both coactivator and NR Box preferences that may contribute to the specificity of hormonal responses.

Magnesium modulates ouabain action on angiotensin II-induced aldosterone synthesis in vitro

Ouabain can block the action of angiotensin II (AII on aldosterone secretion in both rat and human adrenal tissue although its action is much more potent on human zona glomerulosa cells (ZG). Since magnesium can antagonize digitalis action in vivo, we have examined the interaction of both agents on aldosterone secretion in both rat and human adrenal cells. Ouabain itself at high concentration (10(-5) M) in Mg++ buffer blocks AII action on aldosterone secretion on rat ZG cells and at 1000-fold lower concentrations inhibits AII-action in human cells as previously reported by us. When buffer Mg++ is higher (4mM) than normal (0.7 mM) in cultured human adrenal cells it decreases both basal aldosterone secretion (8.6 +/- 0.4 vs. 6.8 +/- 0.2, p < 0.001) and AII action on aldosterone (13.9 +/- 0.6 vs. 9.7 +/- 0.7 ng/10(6) cells/h, p < 0.01). High Mg++ buffer had this effect at both 10(-8) and 10(-7) M concentrations of ouabain (control 8.6 +/- 0.4, AII [10(-9) M] 13.9 +/- 0.7, AII + Ouabain [5 x 10(-8) M] 10.9 +/- 0.6, AII + ouabain [10(-7) M] 7.8 +/- 0.3 ng/10(6) cells/h, both p < 0.01 vs. AII). In contrast, a low Mg++ buffer stimulated both basal (6.9 +/- 0.2 vs. 8.3 +/- 0.4 ng/10(6) cells/h, p < 0.01) and AII stimulation of aldosterone secretion (8.4 +/- 0.2 vs. 9.8 +/- 0.4 ng/10(6) cells/h, p < 0.01). When ouabain was added to low Mg++ buffer there was further inhibition of AII induced aldosterone secretion than with normal Mg++ buffer. However, the effect of ACTH on aldosterone was not altered by changes in Mg++. We conclude that ouabain actions and the effect of angiotensin II on aldosterone is inhibited by an increased level of Mg++ while low levels of Mg++ are stimulatory to both basal and AII action on aldosterone.

Potent inhibitors of human immunodeficiency virus type 1 integrase: identification of a novel four-point pharmacophore and tetracyclines as novel inhibitors

A four-point pharmacophore was constructed from energy-minimized structures of chicoric acid and dicaffeoylquinic acid. The search of 206,876 structures in the National Cancer Institute 3D database yielded 179 compounds that contain this pharmacophore. Thirty-nine of these compounds were tested in an in vitro assay specific for human immunodeficiency virus type 1 integrase (IN). Each retrieved structure was fit to the pharmacophore, and the conformation that afforded the best fit was identified. Twenty of the 39 compounds tested exhibited IC50 values of < 20 microM. Among the most potent inhibitors, tetracyclines emerged as a new class of inhibitors. Although the parent tetracycline exhibited marginal potency against purified IN, all substituted tetracyclines tested showed 5-100-fold increased potency. Disintegration assays with truncated IN mutants indicated that tetracyclines inhibit the IN catalytic core domain. To investigate whether chelation of divalent metals is implicated in differential potency of tetracyclines, enzyme assays were performed in the presence of both Mn2+ or Mg2+; no significance difference in potency was observed. Rolitetracycline inhibited IN/DNA complex formation in the presence of EDTA, which suggests that inhibition was metal independent. Rolitetracycline reversed DNA binding of IN after the complex was allowed to form before the addition of drug. Selectivity of tetracyclines was also examined in an assay specific for topoisomerase I, and none of the tetracyclines tested induced topoisomerase I-mediated cleavable complex or inhibited camptothecin-induced cleavable complex. Remarkable potency against the IN in the absence of divalent metals and the core enzyme coupled with water solubility makes tetracyclines potential candidates for X-ray crystal structure determination with IN.

Identification of amino acids in the tau 2-region of the mouse glucocorticoid receptor that contribute to hormone binding and transcriptional activation

The tau 2-region of steroid hormone receptors is a highly conserved region located at the extreme N-terminal end of the hormone-binding domain. A protein fragment encoding tau 2 has been shown to function as an independent transcriptional activation domain; however, because this region is essential for hormone binding, it has been difficult to determine whether the tau 2-region also contributes to the transactivation function of intact steroid receptors. In this study a series of amino acid substitutions were engineered at conserved positions in the tau 2-region of the mouse glucocorticoid receptor (mGR, amino acids 533-562) to map specific amino acid residues that contribute to the hormone-binding function, transcriptional activation, or both. Substitution of alanine or glycine for some amino acids (mutations E546G, P547A, and D555A) reduced or eliminated hormone binding, but the transactivation function of the intact GR and/or the minimum tau 2-fragment was unaffected for each of these mutants. Substitution of alanine for amino acid S561 reduced transactivation activity in the intact GR and the minimum tau 2-fragment but had no effect on hormone binding. The single mutation L550A and the double amino acid substitution L541G+L542G affected both hormone binding and transactivation. The fact that the S561A and L550A substitutions each caused a loss of transactivation activity in the minimum tau 2-fragment and the full-length GR indicated that the tau 2-region does contribute to the overall transactivation function of the full-length GR. Overall, the N-terminal portion of the tau 2-region (mGR 541-547) was primarily involved in hormone binding, whereas the C-terminal portion of the tau 2-region (mGR 548-561) was primarily involved in transactivation.

Immunoreactivity of presenilin-1 in human, rat and mouse brain

Monoclonal antibodies (mAbs) D3G6 and C8A5, specific for amino acid residues 160-168 of S182 protein, immunolabeled neurons, ependymal and choroid plexus cells, and myocytes in brain sections from normal subjects and people with Alzheimer disease or Down syndrome and in rats and mice. Oligodendroglia, microglia, and the majority of astrocytes were negative. S182 protein or a fragment of the protein detected with these mAbs is not a constituent of amyloid-beta deposits or tangles.

GRIP1, a transcriptional coactivator for the AF-2 transactivation domain of steroid, thyroid, retinoid, and vitamin D receptors

After binding to enhancer elements, transcription factors require transcriptional coactivator proteins to mediate their stimulation of transcription initiation. A search for possible coactivators for steroid hormone receptors resulted in identification of glucocorticoid receptor interacting protein 1 (GRIP1). The complete coding sequence for GRIP1, isolated from a mouse brain cDNA library, contains an open reading frame of 1,462 codons. GRIP1 is the probable ortholog of the subsequently identified human protein transcription intermediary factor 2 (TIF2) and is also partially homologous to steroid receptor coactivator 1 (SRC-1). The full-length GRIP1 interacted with the hormone binding domains (HBDs) of all five steroid receptors in a hormone-dependent manner and also with HBDs of class II nuclear receptors, including thyroid receptor alpha, vitamin D receptor, retinoic acid receptor alpha, and retinoid X receptor alpha. In contrast to agonists, glucocorticoid antagonists did not promote interaction between the glucocorticoid receptor and GRIP1. In yeast cells, GRIP1 dramatically enhanced the transcriptional activation function of proteins containing the HBDs of any of the above-named receptors fused to the GAL4 DNA binding domain and thus served as a transcriptional coactivator for them. This finding contrasts with previous reports of TIF2 and SRC-1, which in mammalian cells enhanced the transactivation activities of only a subset of the steroid and nuclear receptors that they physically interacted with. GRIP1 also enhanced the hormone-dependent transactivation activity of intact glucocorticoid receptor, estrogen receptor, and mineralocorticoid receptor. Experiments with glucocorticoid receptor truncation and point mutants indicated that GRIP1 interacted with and enhanced the activity of the C-terminal AF-2 but not the N-terminal AF-1 transactivation domain of the glucocorticoid receptor. These results demonstrate directly that AF-1 and AF-2 domains accomplish their transactivation activities through different mechanisms: AF-2 requires GRIP1 as a coactivator, but AF-1 does not.

Yeast hormone response element assays detect and characterize GRIP1 coactivator-dependent activation of transcription by thyroid and retinoid nuclear receptors

The mouse glucocorticoid receptor-interacting protein (GRIP1) is a member of the ERAP160 family of nuclear receptor (NR) coactivators (including SRC-1 and TIF2) which function as bridging proteins between ligand-activated NRs bound to cognate hormone-response elements (HREs) and the transcription initiation apparatus (TIA). Although these coactivators bind to several NRs, studies overexpressing these coactivators with these NRs in mammalian cells have not uniformly observed a corresponding enhancement of ligand-dependent transactivation. Here, we show that GRIP1 interacts in vitro in a ligand-dependent manner with thyroid receptor, retinoic acid receptor, and retinoid X receptor. Additionally, in yeast (Saccharomyces cerevisiae) GRIP1 coactivator protein markedly increased the ability of these full-length class II NRs to transactivate beta-galactosidase reporter genes containing cognate HREs. The magnitude of GRIP1 enhancement of liganded NR homodimer was dependent upon NR subtype and HRE configuration. For most HRE configurations, thyroid receptor and retinoic acid receptor homodimers were essentially unresponsive or very weakly active in the absence of GRIP1, but GRIP1 dramatically restored the ligand-dependent function of these NRs. Although GRIP1 exerted no significant effect on NR homodimers in the absence of their cognate ligands, it increased the transactivation of unliganded NR heterodimers. Whether GRIP1 increased ligand-dependent transactivation of a heterodimer to levels greater than that of the cognate homodimer was determined by HRE configuration and copy number. Compared with the limitations of yeast two-hybrid and mammalian coexpression systems, the yeast HRE-assay systems described in this report facilitated both the detection of putative mammalian NR coactivator function and the elucidation of their mechanisms of transactivational enhancement.

Discovery of HIV-1 integrase inhibitors by pharmacophore searching

Based upon a class of known HIV-1 integrase inhibitors, several pharmacophore models were proposed from molecular modeling studies and validated using a 3D database of 152, compounds for which integrase assay data are known. Using the most probable pharmacophore model as the query, the NCI 3D database of 206,876 compounds was searched, and 340 compounds that contain the pharmacophore query were identified. Twenty-nine of these compounds were selected and tested in the HIV-1 integrase assay. This led to the discovery of 10 novel, structurally diverse HIV-1 integrase inhibitors, four of which have an IC50 value less than 30 microM and are promising lead compounds for further HIV-1 integrase inhibitor development.

HIV-1 integrase pharmacophore: discovery of inhibitors through three-dimensional database searching

Starting from a known inhibitor of human immunodeficiency virus type 1 (HIV-1) integrase (IN); caffeic acid phenethyl ester (CAPE), a putative three-point pharmacophore for binding of inhibitors to IN was derived. This pharmacophore was used to search the National Cancer Institute three-dimensional (3D) structural database. Out of the open, nonproprietary part of this database, comprising approximately 200000 compounds, 267 structures were found to match the pharmacophore in at least one conformation, and 60 of those were tested in an in vitro assay against HIV-1 IN. Out of these, 19 were found to inhibit both the 3'-processing and strand transfer of IN at micromolar concentrations. In order to test the validity of this pharmacophore, a small 3D database of 152 published IN inhibitors was built. A search in this database yielded a statistically significant correlation of the presence of this pharmacophore and the potency of the compounds. An automated pharmacophore identification procedure performed on this set of compounds provided additional support for the importance of this pharmacophore for binding of inhibitors to IN and hinted at a possible second pharmacophore. The role of aromatic moieties in the binding of ligands to HIV-1 IN through interactions with divalent metal cations, which are known to be necessary for activity of the enzyme, was explored in ab initio calculations.

Depsides and depsidones as inhibitors of HIV-1 integrase: discovery of novel inhibitors through 3D database searching

Seventeen lichen acids comprising despides, depsidones, and their synthetic derivatives have been examined for their inhibitory activity against HIV-1 integrase, and two pharmacophores associated with inhibition of this enzyme have been identified. A search of the NCI 3D database of approximately 200,000 structures yielded some 800 compounds which contain one or the other pharmacophore. Forty-two of these compounds were assayed for HIV-1 integrase inhibition, and of these, 27 had inhibitory IC50 values of less than 100 microM; 15 were below 50 microM. Several of these compounds were also examined for their activity against HIV-2 integrase and mammalian topoisomerase I.

Hydrazide-containing inhibitors of HIV-1 integrase

Inhibitors of HIV integrase are currently being sought as potential new therapeutics for the treatment of AIDS. A large number of inhibitors discovered to date contain the o-bis-hydroxy catechol structure. In an effort to discover structural leads for the development of new HIV integrase inhibitors which do not rely on this potentially cytotoxic catechol substructure, NSC 310217 was identified using a three-point pharmacophore search based on its assigned structure N-(2-hydroxybenzoyl)-N-(2-hydroxy-3-phenoxypropyl)hydrazine (1). When a sample of NSC 310217 was obtained from the NCI repository, it was shown to exhibit potent inhibition of HIV-1 integrase (3'-processing IC50 = 0.6 microgram/mL). In work reported herein, we demonstrate that NSC 310217, rather than containing 1, which has no inhibitory potency against HIV-1 integrase, is comprised of roughly a 1:1 mixture of N-(2-hydroxybenzoyl)-N'-(2-hydroxy-3-phenoxypropyl)hydrazine (6) and N,N'-bis-salicylhydrazine 7, with all inhibitory potency residing with compound 7(IC50 = 0.7 microM for strand transfer). In subsequent structure-activity studies on 7, it is shown that removing a single amide carbonyl (compound 14, IC50 = 5.2 microM) or replacing one aromatic ring system with a naphthyl ring (compound 19, IC50 = 1.1 microM) can be accomplished with little loss of inhibitory potency. Additionally, replacing a single hydroxyl with a sulfhydryl (compound 23, IC50 = 5.8 microM) results in only moderate loss of potency. All other modifications examined, including the replacement of a single hydroxyl with an amino group (compound 22), resulted in complete loss of potency. Being potent, structurally simple, and non-catechol-containing, compounds such as 7 and 14 may provide useful leads for the development of a new class of HIV integrase inhibitor.

A study of tolerance in a concordant xenograft model

Antibody-mediated rejection appears to constitute the major difference between concordant xenografts and allografts in nonhuman primates. Consistent with its known effect on antibody responses, 5-7 addition of DSG to the conditioning regimen has extended concordant primate xenograft survival for up to 6 months after discontinuation of conventional immunosuppression. In contrast to our observations in recipients of renal allografts, donor-specific skin graft rejection can occur and even in long-term recipients may induce rejection of a previously accepted renal xenograft.

Coumarin-based inhibitors of HIV integrase

The structures of a large number of HIV-1 integrase inhibitors have in common two aryl units separated by a central linker. Frequently at least one of these aryl moieties must contain 1,2-dihydroxy substituents in order to exhibit high inhibitory potency. The ability of o-dihydroxy-containing species to undergo in situ oxidation to reactive quinones presents a potential limitation to the utility of such compounds. The recent report of tetrameric 4-hydroxycoumarin-derived inhibitor 5 provided a lead example of an inhibitor which does not contain the catechol moiety. Compound 5 represents a large, highly complex yet symmetrical molecule. It was the purpose of the present study to determine the critical components of 5 and if possible to simplify its structure while maintaining potency. In the present study, dissection of tetrameric 5 (IC50 = 1.5 microM) into its constituent parts showed that the minimum active pharmacophore consisted of a coumarin dimer containing an aryl substituent on the central linker methylene. However, in the simplest case in which the central linker aryl unit consisted of a phenyl ring (compound 8, IC50 = 43 microM), a significant reduction in potency resulted by removing two of the original four coumarin units. Replacement of this central phenyl ring by more extended aromatic systems having higher lipophilicity improved potency, as did the addition of 7-hydroxy substituents to the coumarin rings. Combining these latter two modifications resulted in compounds such as 3,3'-(2-naphthalenomethylene)bis[4,7-dihydroxycoumarin] (34, IC50 = 4.2 microM) which exhibited nearly the full potency of the parent tetramer 5 yet were structurally much simpler.

Effect of methadone addiction on glucose metabolism in rats

Female albino rats were exposed to methadone over a 35-day period by addition of the drug in their drinking water. The final dose of the drug was 1.8 mg/kg body weight per day. After this period, the drug was withdrawn from some animals for 30 days (postexposure). Compared to unexposed controls, serum glucose levels rose during exposure and returned to control levels postexposure. Oral glucose tolerance tests showed impairment in 35-day drug-exposed animals compared to controls and postexposure. The activities of three key enzymes of glycolysis and three key enzymes of gluconeogenesis were measured in liver during and at the end of the exposure period, as well as postexposure. Compared to unexposed controls and postexposure, specific activities of two glycolytic enzymes in livers of exposed animals-hexokinase and phosphofructokinase 1-were significantly reduced, whereas the activity of a third glycolytic enzyme-pyruvate kinase-was unchanged. The specific activities of two gluconeogenic enzymes-glucose-6-phosphatase and fructose-1,6-biphosphatase-were significantly elevated in the drug-exposed animals compared to controls, whereas the activity of a third enzyme-phosphoenolpyruvate carboxykinase-was unchanged. These data indicate that methadone addiction produces a metabolic state similar to insulin-resistant diabetes.

Instability of Rts1 (drug-resistant factor) replicon: stabilization by DNA fragments derived from Rts1

Rts1 is a large naturally occurring plasmid which has a kanamycin resistance gene and exhibits various temperature-sensitive phenotypes. A smaller derivative of plasmid, pOK, contains the Rts1 replicon and the kanamycin resistance gene of Rts1. This plasmid, pOK, is much more unstable than Rts1 at 42.5 degrees C. A DNA fragment, G3, 1590 nucleotides long from Rts1 DNA, stabilized pOK completely at 42.5 degrees C but only in the cis configuration. G3 did not change the copy number of pOK. The pOK derivative containing G3 was destabilized by the presence of a compatible plasmid containing G3. G3 has four inverted repeats, two 14-base direct repeats, and three ORFs. Smaller fragment of G3 also had a stabilization effect and these studies showed that the ORF does not play any role in stabilization.

GRIP1, a novel mouse protein that serves as a transcriptional coactivator in yeast for the hormone binding domains of steroid receptors

The yeast two-hybrid system was used to isolate a clone from a 17-day-old mouse embryo cDNA library that codes for a novel 812-aa long protein fragment, glucocorticoid receptor-interacting protein 1 (GRIP1), that can interact with the hormone binding domain (HBD) of the glucocorticoid receptor. In the yeast two-hybrid system and in vitro, GRIP1 interacted with the HBDs of the glucocorticoid, estrogen, and androgen receptors in a hormone-regulated manner. When fused to the DNA binding domain of a heterologous protein, the GRIP1 fragment activated a reporter gene containing a suitable enhancer site in yeast cells and in mammalian cells, indicating that GRIP1 contains a transcriptional activation domain. Overexpression of the GRIP1 fragment in mammalian cells interfered with hormone-regulated expression of mouse mammary tumor virus-chloramphenicol acetyltransferase gene and constitutive expression of cytomegalovirus-beta-galactosidase reporter gene, but not constitutive expression from a tRNA gene promoter. This selective squelching activity suggests that GRIM can interact with an essential component of the RNA polymerase II transcription machinery. Finally, while a steroid receptor HBD fused with a GAL4 DNA binding domain did not, by itself, activate transcription of a reporter gene in yeast, coexpression of this fusion protein with GRIP1 strongly activated the reporter gene. Thus, in yeast, GRIP1 can serve as a coactivator, potentiating the transactivation functions in steroid receptor HBDs, possibly by acting as a bridge between HBDs of the receptors and the basal transcription machinery.