155 ORAL Treatment of colorectal tumors with apoptosis inducing TRAIL receptor antibodies HGS-ETR1 and HGS-ETR2 in combination with radiotherapy: additive effects in vitro and dose dependent growth delay in vivo

ABSTRACT The effect of oestrogen on the release and synthesis of LH and FSH was studied in rat adenohypophyses incubated for a period of 4 h in flasks containing 1 ml Eagle's medium. One hemipituitary was used as the experimental gland and the other half served as a control. The spontaneous release of LH and FSH by glands from ovarectomized rats was not affected by oestradiol-17β added to the incubation medium in doses of 55, 166, 500 and 1500 ng/ml. The amount of hormones released by pituitaries from spayed rats injected with oestradiol benzoate (2.5, 5.0 and 10.0 μg/rat) 2 h or 24 h before killing the animals too was not different from that of oil-injected rats. Neither was there any effect of oestrogen when added to the incubation medium of glands from oestrogen-pre-treated rats. However, the concentration of LH and FSH in the gland increased when oestrogen was added to the incubation medium, indicating enhanced synthesis. The effect was dose-dependent up to the dose of 500 ng/ml oestradiol but a dose of 1500 ng/ml was less effective. Increased synthesis of LH but not of FSH was also observed in incubated glands from rats injected with oestrogen 24 h before death, but no changes were seen in those of rats killed 2 h after treatment. Additive effects occurred with the in vivo and in vitro steroid treatment. These results indicate that oestrogen favours synthesis of LH and FSH in cultured pituitaries, without affecting gonadotrophin secretion and that the changes induced in the in situ gland by oestrogen treatment are reflected by their in vitro activity.

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Dose-Dependent Sorafenib-Induced Immunosuppression Is Associated with Aberrant NFAT Activation and Expression of PD-1 in T Cells

Cancers ◽

10.3390/cancers11050681 ◽

2019 ◽

Vol 11 (5) ◽

pp. 681 ◽

Cited By ~ 9

Author(s):

Renuka V. Iyer ◽

Orla Maguire ◽

Minhyung Kim ◽

Leslie I. Curtin ◽

Sandra Sexton ◽

...

Keyword(s):

T Cells ◽

Low Dose ◽

Growth Delay ◽

High Dose ◽

Dependent Manner ◽

Sorafenib Treatment ◽

Baseline Activity ◽

Dose Dependent

The multikinase inhibitor sorafenib is the only standard first-line therapy for hepatocellular carcinoma (HCC). Here, we report the dose-dependent effects of sorafenib on the immune response, which is related to nuclear factor of activated T cells 1 (NFAT1) activity. In vitro and in vivo experiments were performed with low and high doses of sorafenib using human T cells and spontaneous developed woodchuck HCC models. In vitro studies demonstrated that following exposure to a high dose of sorafenib the baseline activity of NFAT1 in T cells was significantly increased. In a parallel event, high dose sorafenib resulted in a significant decrease in T cell proliferation and increased the proportion of PD-1 expressing CD8+ T cells with NFAT1 activation. In the in vivo model, smaller tumors were detected in the low-dose sorafenib treated group compared to the placebo and high-dose treated groups. The low-dose sorafenib group showed a significant tumor growth delay with significantly more CD3+ cells in tumor. This study demonstrates that sorafenib has immunomodulatory effects in a dose- and time-dependent manner. Higher dose of sorafenib treatment was associated with immunosuppressive action. This observed effect of sorafenib should be taken into consideration in the selection of optimum starting dose for future trials.

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Immunization of male rabbits with sheep luteal receptor to LH results in production of antibodies exhibiting hormone-agonistic and -antagonistic activities

Journal of Endocrinology ◽

10.1677/joe.0.1500431 ◽

1996 ◽

Vol 150 (3) ◽

pp. 431-443 ◽

Cited By ~ 6

Author(s):

M Jeyakumar ◽

N R Moudgal

Keyword(s):

Leydig Cells ◽

Serum Testosterone ◽

Fold Increase ◽

Dependent Manner ◽

Primary Immunization ◽

Testosterone Production ◽

Dose Dependent ◽

Receptor Antibodies

Abstract Antibodies to LH/chorionic gonadotrophin receptor (LH/CG-R; molecular weight 67 000), isolated in a homogenous state (established by SDS-PAGE and ligand blotting) from sheep luteal membrane using human CG (hCG)–Sepharose affinity chromatography, were raised in three adult male rabbits (R-I, R-II and R-III). Each of the rabbits received 20–30 μg of the purified receptor in Freund's complete adjuvant at a time. Primary immunization was followed by booster injection at intervals. Production of receptor antibodies was monitored by (1) determining the dilution of the serum (IgG fraction) that could specifically bind 50% of 125I-LH/CG-R added and (2) analysing sera for any change in testosterone levels. Following primary immunization and the first booster, all three rabbits exhibited a 2·5- to 6·0-fold increase in serum testosterone over basal levels and this effect was spread over a period of time (∼40 days) coinciding with the rise and fall of receptor antibodies. The maximal antibody titre (ED50) produced at this time ranged from 1:350 to 1:100 to below detectable limits for R-I, R-II and R-III respectively. Subsequent immunizations followed by the second booster resulted in a substantial increase in anti-body titre (ED50 of 1:5000) in R-I, but this was not accompanied by any change in serum testosterone over preimmune levels, suggesting that with the progress of immunization the character of the antibody produced had also changed. Two pools of antisera from R-I collected 10 days following the booster (at day 70 (bleed I) and day 290 (bleed II)) were used in further experiments. IgG isolated from bleed I but not from bleed II antiserum showed a dose-dependent stimulation of testosterone production by mouse Leydig cells in vitro, thus confirming the in vivo hormone-mimicking activity of antibodies generated during the early immunization phase. The IgG fractions from both bleeds were, however, capable of inhibiting (1) 125I-hCG binding to crude sheep luteal membrane (EC50 of 1:70 and 1:350 for bleed I and II antisera respectively) and (2) ovine LH-stimulated testosterone production by mouse Leydig cells in vitro, indicating the presence of antagonistic antibodies irrespective of the period of time during which the rabbits were immunized. The fact that bleed I-stimulated testosterone production could be inhibited in a dose-dependent manner by the addition of IgG from bleed II to the mouse Leydig cell in vitro assay system showed that the agonistic activity is intrinsic to the bleed I antibody. The receptor antibody (bleed II) was also capable of blocking LH action in vivo, as rabbits passively (for 24 h with LH/CG-R antiserum) as well as actively (for 430 days) immunized against LH/CG-R failed to respond to a bolus injection of LH (50 μg). At no time, however, was the serum testosterone reduced below the basal level. This study clearly shows that, unlike with LH antibody, attempts to achieve an LH deficiency effect in vivo by resorting to immunization with holo LH receptor is difficult, as receptor antibodies exhibit both hormone-mimicking (agonistic) as well as hormone-blocking (antagonistic) activities. Journal of Endocrinology (1996) 150, 431–443

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Soluble Thrombomodulin Purified from Human Urine Exhibits a Potent Anticoagulant Effect In Vitro and In Vivo

Thrombosis and Haemostasis ◽

10.1055/s-0038-1653872 ◽

1995 ◽

Vol 73 (05) ◽

pp. 805-811 ◽

Cited By ~ 12

Author(s):

Yasuo Takahashi ◽

Yoshitaka Hosaka ◽

Hiromi Niina ◽

Katsuaki Nagasawa ◽

Masaaki Naotsuka ◽

...

Keyword(s):

Human Urine ◽

Specific Activity ◽

Anticoagulant Activity ◽

Rabbit Lung ◽

Soluble Thrombomodulin ◽

Molecular Weights ◽

Dose Dependent Fashion ◽

Dose Dependent

SummaryWe examined the anticoagulant activity of two major molecules of soluble thrombomodulin purified from human urine. The apparent molecular weights of these urinary thrombomodulins (UTMs) were 72,000 and 79,000, respectively. Both UTMs showed more potent cofactor activity for protein C activation [specific activity >5,000 thrombomodulin units (TMU)/mg] than human placental thrombomodulin (2,180 TMU/mg) and rabbit lung thrombomodulin (1,980 TMU/mg). The UTMs prolonged thrombin-induced fibrinogen clotting time (>1 TMU/ml), APTT (>5 TMU/ml), TT (>5 TMU/ml) and PT (>40 TMU/ml) in a dose-dependent fashion. These effects appeared in the concentration range of soluble thrombomodulins present in human plasma and urine. In the rat DIC model induced by thromboplastin, administration of UTMs by infusion (300-3,000 TMU/kg) restored the hematological abnormalities derived from DIC in a dose-dependent fashion. These results demonstrate that UTMs exhibit potent anticoagulant and antithrombotic activities, and could play a physiologically important role in microcirculation.

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Vasorelaxant and Antihypertensive Effects of Mentha pulegium L. in Rats: An in vitro and in vivo Approach

Endocrine Metabolic & Immune Disorders - Drug Targets ◽

10.2174/1871530320666200909093908 ◽

2020 ◽

Vol 20 ◽

Author(s):

Mohammed Ajebli ◽

Mohamed Eddouks

Keyword(s):

Blood Pressure ◽

Acute Experiment ◽

Antihypertensive Activity ◽

Mentha Pulegium ◽

In Vitro Experiment ◽

Arterial Blood ◽

Dose Dependent ◽

Ca2 Channels

Aims and objective: The aim of the study was to investigate the effect of aqueous aerial part extract of Mentha pulegium L. (Pennyrile) (MPAE) on arterial pressure parameters in rats. Background: Mentha pulegium is a medicinal plant used to treat hypertension in Morocco. Material and methods: In the current study, MPAE was prepared and its antihypertensive activity was pharmacologically investigated. L-NAME-hypertensive and normotensive rats have received orally MPAE (180 and 300 mg/kg) during six hours for the acute experiment and during seven days for the sub-chronic treatment. Thereafter, systolic, diastolic, mean arterial blood pressure and heart rate were evaluated. While, in the in vitro experiment, isolated denuded and intact thoracic aortic rings were suspended in a tissue bath system and the tension changes were recorded. Results: A fall in blood pressure was observed in L-NAME-induced hypertensive treated with MPAE. The extract also produced a dose-dependent relaxation of aorta pre-contracted with NE and KCl. The study showed that the vasorelaxant ability of MPAE seems to be exerted through the blockage of extracellular Ca2+ entry. Conclusion: The results demonstrate that the extract of pennyrile exhibits antihypertensive activity. In addition, the effect may be, at least in part, due to dilation of blood vessels via blockage of Ca2+ channels.

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Anti-tumor activity of a novel proteasome inhibitor D395 against multiple myeloma and its lower cardiotoxicity compared with carfilzomib

Cell Death and Disease ◽

10.1038/s41419-021-03701-z ◽

2021 ◽

Vol 12 (5) ◽

Author(s):

Xuxing Shen ◽

Chao Wu ◽

Meng Lei ◽

Qing Yan ◽

Haoyang Zhang ◽

...

Keyword(s):

Multiple Myeloma ◽

Proteasome Inhibitor ◽

Osteoclast Differentiation ◽

Dependent Manner ◽

Serum Enzyme ◽

Herg Channels ◽

Anti Tumor Activity ◽

Dose Dependent

AbstractCarfilzomib, a second-generation proteasome inhibitor, has significantly improved the survival rate of multiple myeloma (MM) patients, but its clinical application is still restricted by drug resistance and cardiotoxicity. Here, we identified a novel proteasome inhibitor, D395, and assessed its efficacy in treating MM as well as its cardiotoxicity at the preclinical level. The activities of purified and intracellular proteasomes were measured to determine the effect of D395 on the proteasome. CCK-8 and flow cytometry experiments were designed to evaluate the effects of D395 on cell growth and apoptosis. The effects of D395 and carfilzomib on serum enzyme activity, echocardiography features, cardiomyocyte morphology, and hERG channels were also compared. In our study, D395 was highly cytotoxic to MM cell lines and primary MM cells but not normal cells, and it was well tolerated in vivo. Similar to carfilzomib, D395 inhibited osteoclast differentiation in a dose-dependent manner. In particular, D395 exhibited lower cardiotoxicity than carfilzomib in all experiments. In conclusion, D395 is a novel irreversible proteasome inhibitor that has remarkable anti-MM activity and mild cardiotoxicity in vitro and in vivo.

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In vitro and in vivo applications of Euphorbia wallichii shoot extract-mediated gold nanospheres

Green Processing and Synthesis ◽

10.1515/gps-2021-0013 ◽

2021 ◽

Vol 10 (1) ◽

pp. 101-111

Author(s):

Rehman Ullah ◽

Sumaira Shah ◽

Zahir Muhammad ◽

Sajjad Ali Shah ◽

Shah Faisal ◽

...

Keyword(s):

Gold Nanoparticles ◽

Muscular Contraction ◽

Surface Plasmon Resonance Peak ◽

Plasmon Resonance Peak ◽

Optical Absorption Peak ◽

Visible Spectra ◽

Scattering Spectra ◽

Dose Dependent

Abstract The current study was designed to investigate the potential of Euphorbia wallichii shoot extract for reducting Au3+ and stabilizing gold nanoparticles. UV-visible spectra of gold nanoparticles showed obvious surface plasmon resonance peak at 548 nm. Microscopy (SEM and TEM) showed spherical dimensions, and the energy dispersive X-ray spectra displayed the strongest optical absorption peak for gold (Au) at 2.1 keV. Dynamic light scattering spectra represent polydispersed mixture with particulate diameter of 2.5–103.2 nm. The IR spectra confirm the potential functional groups of shoot extract responsible for the reduction of Au3+ to gold nanoparticles which exhibit tremendous antibacterial potential of 76.31%, 68.47%, 79.85%, 48.10%, and 65.53% against Escherichia coli, Staphylococcus aureus, Bacillus pumilus, Pseudomonas aeruginosa, and Klebsiella pneumoniae, respectively. Gold nanoparticles showed markedly elevated fungicidal potency compared to the shoot extract alone against the tested fungal strains. IC50 for 2,2-diphenyl-1-picrylhydrazyl scavenging was 31.52, 18.29, and 15.32 µg/mL at 30, 60, and 90 min of reaction time, respectively. Both shoot extract and nanoparticles revealed 71% mortality at 100 µg/mL, with LD90 values of 310.56 µg/mL. Experimental mice acquired dose-dependent analgesia of 54.21%, 82.60%, and 86.53% when treated with gold nanoparticles at 50, 100, and 200 mg/kg bw. Inhibition of gastrointestinal muscular contraction was 21.16%, 30.49%, and 40.19% in mice feed with 50, 100, and 200 mg/kg bw, respectively.

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The Use of an Opacitometer to Compare the In Vitro Cornea Opacifying Effects of Timolol With and Without Benzalkonium Chloride

Alternatives to Laboratory Animals ◽

10.1177/026119299101900220 ◽

1991 ◽

Vol 19 (2) ◽

pp. 263-270

Author(s):

Haruyoshi Igarashi ◽

Yasunaga Katsuta ◽

Yoshiharu Nakazato ◽

Tohru Kawasaki

Keyword(s):

Benzalkonium Chloride ◽

Additive Effects ◽

Timolol Maleate ◽

Epithelial Surface ◽

Endothelial Surface ◽

Draize Test ◽

Corneal Opacities

We have evaluated a new in vitro opacitometer method as an alternative to the in vivo Draize test for ocular irritancy. Several concentrations of timolol maleate (timolol) with or without 0.005% benzalkonium chloride were applied to porcine isolated corneas which were either intact or with the epithelium, endothelium, or both epithelium and endothelium removed. Corneal opacities were measured using an opacitometer. In general, timolol with benzalkonium chloride caused a greater degree of opacity to develop in the cornea than did timolol alone. At the lower concentrations of timolol, the increased opacity probably represented additive effects of the two compounds. However, at the highest concentration of timolol (5 x 10 2M), there was an enhanced opacification in the presence of benzalkonium chloride, which may have been due to an increase in penetration, particularly through the epithelium. Timolol caused a greater degree of opacity to develop in the isolated intact porcine corneas when the drug was applied to the endothelial surface, than when applied to the epithelial surface or to both the epithelial and endothelial surfaces. However, timolol with benzalkonium chloride caused a greater degree of opacity in the intact cornea, when the drug was applied to both surfaces than when it was applied only to the epithelial or the endothelial surface.

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