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PubMed1975

Acute and subacute inhalation toxicities of phosphine, phenylphosphine and triphenylphosphine.

The four-hour LC50 values for ChR-CD male rats for phosphine, phenylphosphine and triphenylphosphine have been determined to be 0.44 micromoles per liter (muM/liter), 1.56 muM/liter and 47.8 muM/liter respectively. The dose-death curves are parallel. During exposure, all three caused clinical signs indicative of mild respiratory irritation. Triphenylphosphine also caused severe weight loss immediately after exposure, followed by normal rate of weight gain. No histopathologic effects due to exposure were seen in any of the tissues examined after single exposures to any of the three compounds. Phosphine and triphenylphosphine caused mild weight loss during a 10-day exposure period followed by normal rate of weight gain during a 14-day recovery period. The phenylphosphine exposures caused a decreased rate of weight gain during the exposure period which returned to normal during the recovery period. Silver nitrate paper was found to be unsuitable for field analysis of phenylphosphine.

Air Pollutants↗
PubMed2003

The protective effects of Aspergillus candidus metabolites against hydrogen peroxide-induced oxidative damage to Int 407 cells.

The protective effects of 3,3"-di-OH-terphenyllin (3,3"-DHT) and 3-OH-terphenyllin (3-HT), two secondary metabolites produced by Aspergillus candidus (CCRC31543), against hydrogen peroxide-induced oxidative damage to Int 407 cells, were evaluated. The results showed that H2O2 caused an increase in lactate dehydrogenase (LDH) leakage and DNA damage in Int 407 cells; however, the addition of 3,3"-DHT and 3-HT significantly reduced this effect (P<0.05). Intracellular reactive oxygen species (ROS) formation in Int 407 cells pre-incubated with 3,3"-DHT and 3-HT was decreased by 30 and 35%, respectively. The activity of glutathione peroxidase and catalase in Int 407 cells pre-incubated with 3,3"-DHT was increased 25 and 33%, respectively; however, the activity of catalase was increased 30% in Int 407 cells pre-incubated with 3-HT. The activity of glutathione reductase in Int 407 cells pre-incubated with 3,3"-DHT and 3-HT was decreased 36 and 21%, respectively. The intracellular glutathione level did not vary (P>0.05), but oxidized glutathione levels increased when Int 407 cells were pre-incubated with these two compounds. These findings suggest that 3,3"-DHT and 3-HT have the ability to protect against oxidative damage to Int 407 cells and that this protective effect may be associated with the ability to reduce ROS formation and increase catalase activity.

Antioxidants↗
PubMed1975

Control of snail hosts of bilharziasis in Egypt. 2. Effect of triphenyltin hydroxide (Du-Ter) on carbohydrate metabolism of the snails Biomphalaria alexandria and Bulinus tuncatus.

Previous work has shown that the aerobic oxidation of certain intermediates of Krebs cycle by the snail B. alexandrina and B. truncatusis inhibited by TPT. This paper reports data on the effect of TPT on glucose utilization, glycolysis, glycogen content, and glucone ogenesis in snail tissue preparations. The compounds at its LC50 inhibited gluconeogenesis, stimulated glycolysis and markedly reduced the glycogen content and glucose utilization in both snails. However, the effects were more pronounced in B. truncatus than in B. alexandrina. Possible interpretations of these findings are discussed with reference to published arrangements for regulation of gluconeogenesis and glycolysis, coupling of electorn transport to ATP synthesis and also to our present knowledge of the chemical and biological specificity of TPT.

Animals↗
PubMed1989

Effect of triphenylacrylonitrile derivatives on estradiol-receptor binding and on human breast cancer cell growth.

In a study of a series of 26 triphenylacrylonitrile derivatives (TPEs), we investigated the influence of several possibly interrelated factors on the proliferation of human breast cancer cell lines. (1) Chemical substituents: the test compounds were for the most part para-hydroxylated with increasingly bulky hydrophobic and/or basic side chains [isopropyloxy or (diethylamino)ethoxy] or standard reference compounds. (2) Relative binding affinities (RBAs): they competed diversely for [3H]estradiol (E2) binding to calf uterus cytosol and little, if at all, for binding to the [3H]tamoxifen-labeled antiestrogen binding site (AEBS) in lower speed supernatant. A multiparametric comparison of RBAs recorded for calf, rat, and mouse uterus cytosol estrogen receptor (ER) revealed a possible influence of species-specific receptor conformation and/or environment on binding. (3) Estrogen/antiestrogen potency: their stimulation and inhibition of the proliferation of the ER-positive human breast cancer cell line (MCF7) was measured. Compounds with only hydroxy substituents stimulated proliferation more markedly than methylated derivatives and had a maximum effect at 10(-11)-10(-6) M. Stimulation was related to the RBA for ER. Compounds with isopropyloxy or (diethylamino)ethoxy side chains only weakly stimulated MCF7 cell growth and more powerfully antagonized E2-promoted growth. The extent of inhibition depended upon the bulk of the side chain and could be reversed by 10(-7) M E2. Within the same concentration ranges, the test compounds were without effect on the BT20 ER-negative cell line. (4) Cytostatic and/or cytolytic activity: most compounds could arrest the proliferation of both MCF7 and BT20 cells at concentrations above 3 x 10(-6) M. This activity was thus independent of ER. Nevertheless, those compounds with a charged hydrophobic side chain, which were the most powerful antagonists of E2-promoted cell growth, were also the most cytotoxic. The overall results for all molecules on all parameters were submitted to a multivariate analysis (correspondence analysis) which revealed the progressive influence of increasing substitution by hydroxy and more bulky groups on the generation of antagonist activity and cytotoxicity.

Animals↗
PubMed1985

Acetoxy-substituted 1,1,2-triphenylbut-1-enes with antiestrogenic and mammary tumor inhibiting properties.

1,1,2-Triphenylbut-1-enes (E- and Z-10-12), which are substituted with one p- and one m-acetoxy group in two different aromatic rings, were synthesized. The E and Z isomers were isolated, and their identity was established by 1H NMR spectroscopy. A study of the structure-activity relationship was carried out with regard to estradiol receptor affinity in vitro, estrogenic and antiestrogenic properties (mouse), inhibition of the hormone-dependent human MCF7 breast cancer cell line in vitro, and the hormone-dependent MXT mammary tumor of the mouse in vivo. Among the tested compounds, (E)- and (Z)-1-(3-acetoxyphenyl)-1-(4-acetoxyphenyl)-2-phenylbut-1-enes+ ++ (E-10 and Z-10) and (Z)-1-(3-acetoxyphenyl)-1-phenyl-2-(4-acetoxyphenyl)-but-1-ene (Z-12) proved to be partial antiestrogens, which lead to an inhibition of the MCF7 cell line. They exert a growth-inhibiting activity on the hormone-dependent MXT mammary carcinoma of the mouse. In the case of E-10 and Z-10, this effect is only slightly weaker than that of 1,1-bis(4-acetoxyphenyl)-2-phenylbut-1-ene (13) and tamoxifen. Under the applied experimental conditions, there were no significant changes of uterine weight as an indicator of estrogenic side effects.

Alkenes↗
PubMed2006

Helical stacking tuned by alkoxy side chains in pi-conjugated triphenylbenzene discotic derivatives.

We report on the synthesis and self-assembly of a new series of discotic molecules containing triphenylbenzene as the core and alkoxy side chain with varying length. It was found that compounds 3 a-c, 4 b and 5 b could form stable gels in several apolar solvents. Transmission electron microscopy (TEM) images revealed that their morphologies were very different for the different alkoxy-substituted organogels. In toluene or hexane, 3 b and 3 c resulted in both left- and right-handed helical fibers, whereas 3 a resulted in straight rigid fibers; 4 b and 5 b resulted in most straight fibers with a few twisted fibers. The results from FT-IR and UV/Vis absorption spectroscopy indicated that the hydrogen bonding and pi-pi interactions were the main driving forces for the formation of the self-assembled gels. Further detailed analysis of their aggregation modes were conducted by UV-visible absorption spectra and X-ray diffraction (XRD) measurements. Based on these findings, the influence of these peripheral alkoxy substituents on the gel formation and the aggregation mode were discussed. The special enhanced fluorescent emissions, which resulted from aggregation, were also found in the gel phase.

Alcohols↗
PubMed2006

High intensity solid-state UV source for time-gated luminescence microscopy.

BACKGROUND: The unique discriminative ability of immunofluorescent probes can be severely compromised when probe emission competes against naturally occurring, intrinsically fluorescent substances (autofluorophores). Luminescence microscopes that operate in the time-domain can selectively resolve probes with long fluorescence lifetimes (tau > 100 micros) against short-lived fluorescence to deliver greatly improved signal-to-noise ratio (SNR). A novel time-gated luminescence microscope design is reported that employs an ultraviolet (UV) light emitting diode (LED) to excite fluorescence from a europium chelate immunoconjugate with a long fluorescence lifetime. METHODS: A commercial Zeiss epifluorescence microscope was adapted for TGL operation by fitting with a time-gated image-intensified CCD camera and a high-power (100 mW) UV LED. Capture of the luminescence was delayed for a precise interval following excitation so that autofluorescence was suppressed. Giardia cysts were labeled in situ with antibody conjugated to a europium chelate (BHHST) with a fluorescence lifetime >500 micros. RESULTS: BHHST-labeled Giardia cysts emit at 617 nm when excited in the UV and were difficult to locate within the matrix of fluorescent algae using conventional fluorescence microscopy, and the SNR of probe to autofluorescent background was 0.51:1. However in time-gated luminescence mode with a gate-delay of 5 mus, the SNR was improved to 12.8:1, a 25-fold improvement. CONCLUSION: In comparison to xenon flashlamps, UV LEDs are inexpensive, easily powered, and extinguish quickly. Furthermore, the spiked emission of the LED enabled removal of spectral filters from the microscope to significantly improve efficiency of fluorescence excitation and capture.

Animals↗
PubMed2004

Time-resolved fluorescence microscopy using an improved europium chelate BHHST for the in situ detection of Cryptosporidium and Giardia.

Fluorescent immunoconjugates prepared with the europium chelate BHHCT (4,4'-bis(1'',1'',1'',2'',2'',3'',3''-heptafluoro-4'',6''-hexanedion-6''-yl)-chlorosulfo-o-terphenyl) have previously been reported as suitable labels for time-resolved fluorescence applications. BHHCT is limited by a tendency to destabilize immunoglobulins when covalently bound to the protein at moderate to high fluorophore to protein ratios (F/P). We report a new derivative of BHHCT prepared by appending a short hydrophylic tether to the chlorosulfonate activating group on BHHCT. The new derivative, BHHST (4,4'-bis-(1'',1'',1'',2'',2'',3'',3''-heptafluoro-4'',6''-hexanedion-6''-yl)sulfonylamino-propyl-ester-N-succinimide-ester-o-terphenyl), was activated to bind at the tether terminus with a succinimide leaving group that displayed less aggressive coupling activity and improved storage stability. BHHST has been used to prepare a stable and useful immunoconjugate with the anti-Cryptosporidium monoclonal antibody CRY104. The BHHST immunoconjugate provides more than a 10-fold enhancement in the signal to noise ratio (SNR) of labeled oocyst fluorescence over background when observed using TRFM techniques. An immunoconjugate was also prepared with BHHST and (goat) anti-mouse that effectively labeled Giardia cysts in situ. Detection of cysts with the TRFM was achieved with an 11-fold increase in SNR when a gate-delay of 60 micros was employed. The storage half-life of both immunoconjugates is extended more than 20-fold when compared to immunoconjugates prepared with BHHCT.

Animals↗
PubMed1997

Highly sensitive time-resolved fluoroimmunoassay of human immunoglobulin E by using a new europium fluorescent chelate as a label.

A new europium fluorescent chelate, 4,4'-bis(1",1",1",2",2",3",3"-heptafluoro-4",6"-hexanedione-6"-yl) - chlorosulfo-o-terphenyl (BHHCT)-Eu3+, was used as a label for highly sensitive time-resolved fluoroimmunoassay of human IgE. Two assay formats were employed in the analysis. In the first format, an immunoconjugate of rabbit anti-human IgE antibody-human IgE-biotinylated goat anti-human IgE antibody-BHHCT-Eu(3+)-labeled SA (or BHHCT-Eu(3+)-labeled BSA-SA; BSA, bovine serum albumin; SA, streptavidin) was used for measurement. The method gives the detection limits of 3.6 x 10(-2) IU/ml (labeled SA) and 1.1 x 10(-2) IU/ml (labeled SA-BSA). In the second format, an immunoconjugate of goat anti-human IgE antibody-human IgE-rabbit anti-human IgE antibody-biotinylated goat anti-rabbit IgG antibody-BHHCT-Eu(3+)-labeled SA (or BHHCT-Eu(3+)-labeled BSA-SA) was used for measurement. The detection limits of these methods are 3.0 x 10(-3) IU/ml (labeled SA) and 1.5 x 10(-3) IU/ml (labeled BSA-SA). The above detection limits are one to two orders of magnitude lower than those of the conventional radioimmunoassay and enzyme immunoassay. The CV of the present method is less than 7%, and the recovery is in the range of 85-105% for serum samples.

Animals↗
PubMed1999

Simultaneous determination of alpha-fetoprotein and carcinoembryonic antigen in human serum by time-resolved fluoroimmunoassay.

A novel simultaneous measurement method for alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) in human sera by time-resolved fluoroimmunoassay (TR-FIA) is described. The proposed approach combines the use of europium-labeled anti-AFP antibody for AFP TR-FIA and biotinylated anti-CEA antibody complexed to samarium-labeled streptavidin for CEA TR-FIA. A 96-well microtiter plate coated with a mixture of anti-AFP and anti-CEA monoclonal antibodies was used for the assay. After it was reacted with a solution containing AFP and CEA, a mixture of anti-AFP antibody labeled with BHHCT-Eu(3+) and biotinylated anti-CEA antibody was added. The AFP concentration was determined by measuring the solid-phase fluorescence of the europium-labeled anti-AFP antibody at 615 nm. Then a BHHCT-Sm(3+)-labeled streptavidin-bovine serum albumin conjugate (SA-BSA) was added to react with the biotinylated anti-CEA antibody. After the reaction, the unreacted SA-BSA was washed out, and a 0.1 M NaOH solution containing 1.0 x 10(-5) M TOPO and 0.05% SDS was added to dissociate the samarium-labeled SA-BSA in the immune complex on the surface of the well into the solution. The CEA concentration was determined by measuring the solution fluorescence of 643 nm from the samarium-labeled SA-BSA. The present method gives detection limits of 0.07 ng/ml for AFP and 0.3 ng/ml for CEA. The coefficient variations of the method are less than 7%, and the recoveries are in the range of 90-110% for serum samples. The AFP and CEA concentrations in 27 human serum samples were determined by the present method as well as by single assay for comparison. A good correlation was obtained with the correlation coefficients of 0.990 for AFP and 0.973 for CEA.

Animals↗
PubMed1994

The effects of polybrominated biphenyls and perchlorinated terphenyls on in vitro fertilization in the mouse.

Polybrominated biphenyls (PBBs) and perchlorinated terphenyls (PCTs) are industrial chemicals that are long-lasting environmental contaminants. Although in vivo effects of PBBs on reproduction are documented, no information is available on the effects of these chemicals on sperm-egg interactions or fertilization. The present study was undertaken to determine the toxic potential of PBBs and PCTs on in vitro fertilization (IVF) in the mouse. 2-Bromobiphenyl, 4-bromobiphenyl, o-terphenyl, m-terphenyl, and p-terphenyl were added to the IVF medium at various concentrations. Oocytes collected from superovulated B6D2F1 mice were maintained in a medium containing the chemicals. Capacitated sperm were then added and the dishes cultured in a humidified atmosphere at 37 degrees C in 5% CO2 + 95% air. Oocytes were assessed for fertilization 20-24 h after insemination. polybrominated biphenyls and PCTs reduced the IVF rate at the higher dosages. Furthermore, an increased incidence of abnormal two-cell embryos and degenerative oocytes was observed at the 1 and 10 micrograms/ml concentrations of PBBs and PCTs. These results indicate that PBBs and PCTs adversely effect IVF and increase the incidence of abnormal embryos and oocyte degeneration in the mouse.

Animals↗
PubMed2004

Exploring QSAR with E-state index: selectivity requirements for COX-2 versus COX-1 binding of terphenyl methyl sulfones and sulfonamides.

An attempt has been made to explore selectivity requirements for cyclooxygenase-2 (COX-2) versus cyclooxygenase-1 (COX-1) binding of terphenyl methyl sulfones and sulfonamides using electrotopological state (E-state) index and suitable indicator parameters. Multiple linear regression analyses produced statistically acceptable equations: the best relation based on 'all-possible-subsets regression' for COX-1 binding (n=18) showed predicted variance and explained variance of 0.675 and 0.777, respectively, while in case of the best equation for COX-2 binding (n=38), these values rose to 0.842 and 0.874, respectively. For the selectivity relation (n=17), predicted variance and explained variance values were 0.601 and 0.687, respectively. Based on the results of the analyses, three important sites have been suggested: sites A (methylsulfonyl or aminosulfonyl moiety), B (central phenyl ring), and C (terminal phenyl ring containing different substituents). All three sites are important for COX-2 binding while sites B and C are important for COX-1 binding. For COX-2 selectivity, only site C plays an important role. The study shows the utility of E-state index in developing statistically acceptable model having direct physicochemical significance.

Binding Sites↗
PubMed2005

Orientational anisotropic studies by field rotation technique: near zero-field pulsed EPR experiments of pentacene doped in p-terphenyl.

We report a new technique to map the orientational anisotropy of paramagnetic systems without physically changing the crystal orientations in near zero-field (NZF) pulsed EPR experiments. By implementing three sets of orthogonal coils around the sample, we are ble to create a magnetic vector up to 2 mT in any three-dimensional orientation in space. In NZF region, the hyperfine tensor elements are comparable to the electronic Zeeman interaction energy, thus very rich spectral patterns can be obtained by "dialing" in a magnetic field vector without moving the sample. The technique further allows us to examine the site symmetry of organic crystals and powdered solids doped with chromophores which can be photo-excited to the triplet state by laser light. The technique is exemplified in the study of pentacene in p-terphenyl crystals.

Algorithms↗