scholarly journals Development of68Ga-Glycopeptide as an Imaging Probe for Tumor Angiogenesis

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Ning Tsao ◽  
Chau-Hui Wang ◽  
Li-Jane Her ◽  
Kai-Yuan Tzen ◽  
Jing-Yi Chen ◽  
...  
Keyword(s):  
New Zealand ◽  
Tumor Angiogenesis ◽  
Half Life ◽  
Tumor Imaging ◽  
In Vivo Studies ◽  
Blood Clearance ◽  
Tumor Uptake ◽  
Tumor Bearing ◽  
New Zealand White Rabbits

Objective. This study was aimed to study tissue distribution and tumor imaging potential of68Ga-glycopeptide (GP) in tumor-bearing rodents by PET.Methods. GP was synthesized by conjugating glutamate peptide and chitosan. GP was labeled with68Ga chloride for in vitro and in vivo studies. Computer outlined region of interest (counts per pixel) of the tumor and muscle (at the symmetric site) was used to determine tumor-to-muscle count density ratios. To ascertain the feasibility of68Ga-GP in tumor imaging in large animals, PET/CT imaging of68Ga-GP and18F-FDG were conducted in New Zealand white rabbits bearing VX2 tumors. Standard uptake value of tumors were determined by PET up to 45 min. To determine blood clearance and half-life of68Ga-GP, blood samples were collected from 10 seconds to 20 min.Results. Radiochemical purity of68Ga-GP determined by instant thin-layer chromatography was >95%. Tumor uptake values (SUV) for68Ga-GP and18F-FDG in New Zealand white rabbits bearing VX2 tumors were 3.25 versus 7.04. PET images in tumor-bearing rats and rabbits confirmed that68Ga-GP could assess tumor uptake. From blood clearance curve, the half-life of68Ga-GP was 1.84 hr.ConclusionOur data indicate that it is feasible to use68Ga-GP to assess tumor angiogenesis.

scholarly journals Design of PSMA ligands with modifications at the inhibitor part: an approach to reduce the salivary gland uptake of radiolabeled PSMA inhibitors?

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Veronika Barbara Felber ◽  
Manuel Amando Valentin ◽  
Hans-Jürgen Wester
Keyword(s):  
Salivary Gland ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
In Vivo Studies ◽  
Tumor Xenograft ◽  
Tumor Uptake ◽  
Lncap Cells ◽  
High Affinity

Abstract Aim To investigate whether modifications of prostate-specific membrane antigen (PSMA)-targeted radiolabeled urea-based inhibitors could reduce salivary gland uptake and thus improve tumor-to-salivary gland ratios, several analogs of a high affinity PSMA ligand were synthesized and evaluated in in vitro and in vivo studies. Methods Binding motifs were synthesized ‘on-resin’ or, when not practicable, in solution. Peptide chain elongations were performed according to optimized standard protocols via solid-phase peptide synthesis. In vitro experiments were performed using PSMA+ LNCaP cells. In vivo studies as well as μSPECT/CT scans were conducted with male LNCaP tumor xenograft-bearing CB17-SCID mice. Results PSMA ligands with A) modifications within the central Zn2+-binding unit, B) proinhibitor motifs and C) substituents & bioisosteres of the P1′-γ-carboxylic acid were synthesized and evaluated. Modifications within the central Zn2+-binding unit of PSMA-10 (Glu-urea-Glu) provided three compounds. Thereof, only natLu-carbamate I (natLu-3) exhibited high affinity (IC50 = 7.1 ± 0.7 nM), but low tumor uptake (5.31 ± 0.94% ID/g, 1 h p.i. and 1.20 ± 0.55% ID/g, 24 h p.i.). All proinhibitor motif-based ligands (three in total) exhibited low binding affinities (> 1 μM), no notable internalization and very low tumor uptake (< 0.50% ID/g). In addition, four compounds with P1′-ɣ-carboxylate substituents were developed and evaluated. Thereof, only tetrazole derivative natLu-11 revealed high affinity (IC50 = 16.4 ± 3.8 nM), but also this inhibitor showed low tumor uptake (3.40 ± 0.63% ID/g, 1 h p.i. and 0.68 ± 0.16% ID/g, 24 h p.i.). Salivary gland uptake in mice remained at an equally low level for all compounds (between 0.02 ± 0.00% ID/g and 0.09 ± 0.03% ID/g), wherefore apparent tumor-to-submandibular gland and tumor-to-parotid gland ratios for the modified peptides were distinctly lower (factor 8–45) than for [177Lu]Lu-PSMA-10 at 24 h p.i. Conclusions The investigated compounds could not compete with the in vivo characteristics of the EuE-based PSMA inhibitor [177Lu]Lu-PSMA-10. Although two derivatives (3 and 11) were found to exhibit high affinities towards LNCaP cells, tumor uptake at 24 h p.i. was considerably low, while uptake in salivary glands remained unaffected. Optimization of the established animal model should be envisaged to enable a clear identification of PSMA-targeting radioligands with improved tumor-to-salivary gland ratios in future studies.

scholarly journals Zr-89 Immuno-PET Targeting Ectopic ATP Synthase Enables In-Vivo Imaging of Tumor Angiogenesis

2019 ◽  
Vol 20 (16) ◽  
pp. 3928
Author(s):  
Bok-Nam Park ◽  
Ga-Hee Kim ◽  
Seung-A Ko ◽  
Ga-Hee Shin ◽  
Su-Jin Lee ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Cellular Uptake ◽  
Tumor Angiogenesis ◽  
Breast Cancer Cells ◽  
Xenograft Model ◽  
Tumor Uptake ◽  
Positron Emission ◽  
Pc3 Cells

In this study, we synthesized a Zr-89-labeled anti-adenosine triphosphate synthase monoclonal antibody (ATPS mAb) for applications in immuno-positron emission tomography (PET) and evaluated its feasibility for angiogenesis imaging. The cellular uptake of Zr-89 ATPS mAb was measured after treatment of cancer cell lines in vitro, and its biodistribution was evaluated at 4, 24 and 48 h in vivo in mice bearing xenografts. PET images were acquired at 4, 24, 48, and 96 h after Zr-89 ATPS mAb administration. Tumor angiogenesis was analyzed using anti-CD31 immunofluorescence staining. The cellular uptake of Zr-89 ATPS mAb increased over time in MDA-MB-231 breast cancer cells but did not increase in PC3 prostate cancer cells. The tumor uptake of Zr-89 ATPS mAb at 24 h was 9.4 ± 0.9% ID/g for MDA-Mb-231 cells and was 3.8 ± 0.6% ID/g for PC3 cells (p = 0.004). Zr-89 ATPS mAb uptake in MDA-MB-231 xenografts was inhibited by the administration of cold ATPS mAb (4.4 ± 0.5% ID/g, p = 0.011). Zr-89 ATPS mAb uptake could be visualized by PET for up to 96 h in MDA-MB-231 tumors. In contrast, there was no distinct tumor uptake detected by PET in the PC3 xenograft model. CD31-positive tumor vessels were abundant in MDA-MB-231 tumors, whereas they were scarcely detected in PC3 tumors. In conclusion, ATPS mAb was successfully labeled with Zr-89, which could be used for immuno-PET imaging targeting tumor angiogenesis.

scholarly journals In Vitro Characterization of Rabbit Thrombin, Antithrombin III, and Thrombin-Antithrombin III Complex, and Determination of Their Survival Times in Vivo

1977 ◽  
Author(s):  
Christine N. Vogel ◽  
Kingdon S. Henry ◽  
Roger L. Lundblad
Keyword(s):  
Gel Electrophoresis ◽  
Half Life ◽  
Antithrombin Iii ◽  
Specific Activity ◽  
Sodium Dodecyl ◽  
In Vivo Studies ◽  
Survival Times ◽  
At Iii

Our intention is to study the interaction of rabbit thrombin with antithrombin III (AT-III) in vitro and in vivo. After activation of crude prothrombin with tissue thromboplastin and CaCl2, thrombin was purified and showed two species of thrombin with molecular weights of 36,000 and 39,000 daltons as determined by sodium dodecyl sulfate discontinuous gel electrophoresis. Rabbit AT-III was purified using a heparin agarose column and had a molecular weight of 55,000 daltons. The inhibition of thrombin by AT-III was followed by fibrinogen clotting assays and an AT-III-thrombin complex was observed on gel electrophoresis. For the in vivo studies both thrombin and AT-III were radiolabelled with Na125i using the solid state lactoperoxidase method and retained 99% of the pre-iodinated specific activity. Radiolabelled thrombin and a radiolabelled AT-III-thrombin complex were injected into different rabbits. The rate of removal of both was very similar with a half-life of approximately 9 hours. When radiolabelled AT-III was injected, the half-life was approximately 60 hours. Since the disappearance rate of thrombin more closely approximates that of the preformed AT-III-thrombin complex and is clearly shorter than the turnover rate of AT-III, the possibility is raised that thrombin combines in vivo with a native inhibitor such as AT-III and may in fact be removed from the circulation as a complex rather than as a native molecule.

scholarly journals Angiostatic activity of the antitumor cytokine interleukin-21

Blood ◽  
2008 ◽  
Vol 112 (13) ◽  
pp. 4940-4947 ◽  
Author(s):  
Karolien Castermans ◽  
Sebastien P. Tabruyn ◽  
Rong Zeng ◽  
Judy R. van Beijnum ◽  
Cheryl Eppolito ◽  
...  
Keyword(s):  
Immune Response ◽  
Tumor Angiogenesis ◽  
Chorioallantoic Membrane ◽  
Antitumor Immune Response ◽  
In Vivo Studies ◽  
Type I ◽  
Stat3 Phosphorylation ◽  
Interleukin 21

Abstract Interleukin-21 (IL-21) is a recently described immunoregulatory cytokine. It has been identified as a very potent immunotherapeutic agent in several cancer types in animal models, and clinical studies are ongoing. IL-21 belongs to the type I cytokine family of which other members, ie, IL-2, IL-15, and IL-4, have been shown to exert activities on vascular endothelial cells (ECs). We hypothesized that IL-21, in addition to inducing the antitumor immune response, also inhibits tumor angiogenesis. In vitro experiments showed a decrease of proliferation and sprouting of activated ECs after IL-21 treatment. We found that the IL-21 receptor is expressed on vascular ECs. Furthermore, in vivo studies in the chorioallantoic membrane of the chick embryo and in mouse tumors demonstrated that IL-21 treatment disturbs vessel architecture and negatively affects vessel outgrowth. Our results also confirm the earlier suggested angiostatic potential of IL-2 in vitro and in vivo. The angiostatic effect of IL-21 is confirmed by the decrease in expression of angiogenesis-related genes. Interestingly, IL-21 treatment of ECs leads to a decrease of Stat3 phosphorylation. Our research shows that IL-21 is a very powerful antitumor compound that combines the induction of an effective antitumor immune response with inhibition of tumor angiogenesis.

scholarly journals In vivo and in vitro suppression of primary B lymphocytopoiesis by tumor-derived and recombinant granulocyte colony-stimulating factor

Blood ◽  
1993 ◽  
Vol 82 (7) ◽  
pp. 2062-2068 ◽  
Author(s):  
MY Lee ◽  
KL Fevold ◽  
K Dorshkind ◽  
R Fukunaga ◽  
S Nagata ◽  
...  
Keyword(s):  
B Cell ◽  
Stromal Cell ◽  
In Vivo Studies ◽  
Granulocyte Colony Stimulating Factor ◽  
B Lymphopoiesis ◽  
Colony Stimulating Factor ◽  
Tumor Bearing ◽  
Stimulating Factor

Transplantation of a granulocytosis-inducing murine CE mammary carcinoma into mice suppresses primary B lymphopoiesis in the marrow. The mechanisms of this tumor-induced B-cell suppression were investigated using Whitlock-Witte-type lymphoid cultures. When seeded with normal marrow progenitors, stromal cells of tumor-bearing mice supported the production of B220+ cells as well as did either stomal cells derived from control mice or the stromal cell line S17. Cultured over normal stroma, marrow cells of tumor-bearing mice depleted of adherent cells and B220+ cells generated B220+ cells as effectively as a similar cell population from control mice. However, interleukin-7- responsive progenitors, were completely depleted from the marrow of tumor-bearing mice. When conditioned medium (CM) of cloned CE tumor cells known to produce granulocyte colony-stimulating factor (G-CSF) and macrophage-CSF, or recombinant murine G-CSF was added to the cultures established with S17 cells, B220+ cell production was significantly diminished. Antiserum to murine G-CSF blocked these effects. These in vitro observations were corroborated by the elimination of marrow B220+ cells in mice injected with G-CSF. These in vitro and in vivo studies suggest that G-CSF plays an inhibitory role in primary B lymphopoiesis by blocking stromal cell-mediated differentiation of early B-cell progenitors into phenotypically recognizable B220+ pre-B cells.

Polymorphonuclear leukocyte cytoplasts mediate acute lung injury

1988 ◽  
Vol 65 (2) ◽  
pp. 706-713 ◽  
Author(s):  
V. B. Antony ◽  
C. L. Owen ◽  
D. English
Keyword(s):  
Acute Lung Injury ◽  
New Zealand ◽  
Lung Injury ◽  
Polymorphonuclear Leukocyte ◽  
Lung Lavage ◽  
Lung Weight ◽  
Endothelial Monolayers ◽  
New Zealand White Rabbits

Injection of phorbol 12-myristate 13-acetate (PMA) into polymorphonuclear leukocyte (PMN)-depleted, PMN cytoplast-repleted New Zealand White rabbits caused the development of acute lung injury in vivo. PMN cytoplasts are nucleus- and granule-free vesicles of cytoplasm capable of releasing toxic O2 radicals but incapable of releasing granule enzymes. PMN cytoplasts when activated by PMA reduced 66 +/- 12.7 nmol of cytochrome c compared with 2.6 +/- 0.7 nmol in their resting state and did not release a significant quantity of granule enzymes (P greater than 0.05). Injection of PMA into New Zealand White rabbits caused a significant decrease (P less than 0.05) in the number of circulating cytoplasts. Increases in lung weight-to-body weight ratios in PMA-treated rabbits (9.8 +/- 0.5 X 10(-3] compared with saline-treated rabbits (5.3 +/- 0.2 X 10(-3] were also noted. Levels of angiotensin-converting enzyme in lung lavage as well as the change in alveolar-arterial O2 ratio correlated with the numbers of cytoplasts in lung lavage (P = 0.001, r = 0.84 and P = 0.0166, r = 0.73, respectively). Albumin in lung lavage increased to 1,700 +/- 186 mg/ml in PMA-treated rabbits from 60 +/- 30 mg/ml in saline-treated rabbits. These changes were attenuated by pretreatment of rabbits with dimethylthiourea (DMTU). In vitro, cytoplasts were able to mediate increases in endothelial monolayer permeability. This was evidenced by increases in fractional transit of albumin across endothelial monolayers when treated with PMA-activated cytoplasts (0.08 +/- 0.01 to 0.28 +/- 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Interleukin-35 promotes early endothelialization after stent implantation by regulating macrophage activation

2019 ◽  
Vol 133 (7) ◽  
pp. 869-884 ◽  
Author(s):  
Xianglan Liu ◽  
Ruoxi Zhang ◽  
Jingbo Hou ◽  
Jian Wu ◽  
Maomao Zhang ◽  
...  
Keyword(s):  
New Zealand ◽  
Cross Sections ◽  
Inflammatory Responses ◽  
Umbilical Vein ◽  
Neointimal Hyperplasia ◽  
Macrophage Phenotype ◽  
New Zealand White Rabbits ◽  
Anti Inflammatory

Abstract Background: Early strut coverage after sirolimus-eluting stent (SES) implantation is associated with the activation of inflammation, but the underlying mechanisms are not completely understood. The present study aimed to identify the relationship between the anti-inflammatory cytokine interleukin (IL) 35 (IL-35) and early strut coverage in vivo and in vitro. Methods: We utilized a retrospective study design to measure IL-35 levels in 68 stents from 68 patients with coronary artery disease and recorded serial optical coherence tomography (OCT) images (0 and 3 months) to assess stent endothelialization. The mechanism underlying the regulatory effects of IL-35 on macrophages and human umbilical vein endothelial cells (HUVECs) was also investigated. SESs were surgically implanted into the right common carotid arteries of 200 male New Zealand White rabbits receiving intravenous injections of IL-35 or a placebo. Results: At the 3-month OCT evaluation, complete endothelium coverage was correlated with IL-35 levels. IL-35 induced the activation of an anti-inflammatory M2-like macrophage phenotype by targeting the signal transducer and activators of transcription (STAT)1/4 signalling pathway, and IL-35-treated macrophages induced endothelial proliferation and alleviated endothelial dysfunction. IL-35-treated New Zealand White rabbits with implanted SESs showed lower percentages of cross-sections with an uncovered strut, elevated mean neointimal hyperplasia (NIH) thickness, and inhibited inflammatory responses. Conclusions: We investigated the effect of IL-35 expression on early stent endothelialization in vivo and in vitro and identified a crucial role for IL-35 in inducing the activation of an anti-inflammatory M2-like macrophage phenotype. The present study highlights a new therapeutic strategy for early stent endothelialization.

In Vitro Effect of the Biomechanics After Photodynamic Therapy (PDT) Intervention on Rabbit Cornea

2021 ◽  
Author(s):  
Guanyu Su ◽  
Shaofeng Han ◽  
Bowen Song ◽  
Kai Cao ◽  
Qingfeng Liang
Keyword(s):  
New Zealand ◽  
Anterior Chamber ◽  
Toluidine Blue ◽  
Red Light ◽  
Tangent Modulus ◽  
Control Group ◽  
Rabbit Cornea ◽  
Corvis St ◽  
New Zealand White Rabbits

Abstract Objective: To observe the change of the biomechanical properties of rabbit cornea after the intervention by corneal collagen cross linking (CXL) and toluidine blue O combined with red light (TBOR).Methods: The study was carried out in compliance with the ARRIVE guidelines. 20 healthy adult New Zealand white rabbits were randomly divided into two groups. One group was taken with Riboflavin combined with UV light therapy in the right eye of healthy New Zealand white rabbits, and the other group was taken toluidine blue O combined with red light (TBOR) treatment. All left eyes were taken as controls. Parameters, from Pentacam and Corvis ST like K1 (The keratometry readings of the flattest), K2 (The keratometry readings of the steepest), ACD (Anterior chamber depth), Pupil diameter, ACA (Mean angle of the anterior chamber), ACV (Volume of the anterior chamber), bIOP (Biomechanical Intraocular pressure), CT (Corneal thickness, pachymetry), A1 Time(Time from starting until the first applanation), A1 Velocity(Corneal speed during the first applanation moment), A2 Time (Time from starting until the second applanation), A2 Velocity (Corneal speed during the second applanation moment), HC Time(Time from starting until highest concavity is reached), Peak Dist(Distance of the two “peaks” at highest concavity) and HC-Radius(The radius at highest concavity), were examined before and 2 weeks after intervention. The rabbits were sacrificed after anesthesia. Then, their corneas were removed for corneal stretch test.Results: With the examination of Pentacam and Corvis ST, IOP(11.28 ± 11.2mmHg v.s. 6.66 ± 4.02mmHg) and A1 time(7.03 ± 1.27s v.s. 6.55 ± 0.35s) were increased, comparing with those before intervention. From the in vitro corneal stretch test, the tangent modulus of the CXL group was more than 3 times of the Control group, whereas the tangent modulus of the TBOR group was about 0.7 times to that of the Control group.Conclusions: From the rabbit cornea intervention with CXL and TBOR, CXL showed an obvious effect of increasing the hardness of rabbit cornea, while TBOR may did no help to increase the hardness of cornea.

INTRAVENOUS BACTERIAL LIPOPOLYSACCHARIDE IMPAIRS MONOCYTE TISSUE FACTOR GENERATION IN RABBITS

1987 ◽  
Author(s):  
R Edwards ◽  
W Brande
Keyword(s):  
New Zealand ◽  
Tissue Factor ◽  
Blood Coagulation ◽  
Mononuclear Cell ◽  
Suppressor Activity ◽  
Arterial Blood ◽  
New Zealand White Rabbits ◽  
Mo Content

Bacterial 1ipopolysaccharide (LPS) ts a potent stimulus for monocyte tissue factor (MTF) generation jn. vitro. We have examined the effect of small amounts of LPS on MTF expression in vivo. LPS (0.1 - 50ug) was injected into the ear veins of 66 New Zealand White rabbits. Arterial blood was collected immediately prior to LPS (TO), and 5 (T5) and 30 (T30) minutes later. Mononuclear cell suspensions (MC) were assessed for monocyte (Mo) content and MTF generation was determined in both unstimulated and LPS-stimulated MC cultures (18 hours incubation). As seen in the table, T5 cells obtained following in vivo exposure to 5 or lOug LPS demonstrated spontaneous MTF generation in the absence of in vitro stimulation. By T30, the Mo content of MC decreased from 28% to 17% and MTF generation was decreased in both stimulated and unstimulated cultures. However, this decreased MTF could not be explained by reduction in Mo number. In reconstitution experiments, T30 lymphoctes (Ly) did not suppress TO MTF generation and TO Ly did not restore T30 MTF generation, suggesting that the decreased MTF generation is not mediated by increased Ly suppressor activity. Neither heparin, warfarin nor hydrocortisone had any effect on Mo count or on MTF generation. These experiments suggest that small amounts of LPS activate a subpopulation of Mo, which is quickly lost from the circulation, while the remaining Mo are resistant to further LPS stimulation. Direct activation of this subpopulation of competent Mo by LPS may contribute to activation of blood coagulation in sepsis.

scholarly journals Once-versus thrice-daily netilmicin combined with amoxicillin, penicillin, or vancomycin against Enterococcus faecalis in a pharmacodynamic in vitro model.

1996 ◽  
Vol 40 (10) ◽  
pp. 2258-2261 ◽  
Author(s):  
S Schwank ◽  
J Blaser
Keyword(s):  
Enterococcus Faecalis ◽  
Half Life ◽  
In Vitro Model ◽  
Bacterial Biofilm ◽  
In Vivo Studies ◽  
Bacterial Killing ◽  
Once Daily ◽  
Vitro Model

Several in vitro and in vivo studies as well as clinical trials have demonstrated that once-daily aminoglycoside regimens are as effective as or more effective than multiple daily dosings. However, the most favorable aminoglycoside dosing regimen for treating enterococcal endocarditis remains controversial. The same total dose of netilmicin was administered as once-daily (24-micrograms/ml peaks) and thrice-daily (8 micrograms/ml) regimens in a pharmacodynamic in vitro model simulating exposure of Enterococcus faecalis to human serum kinetics. Netilmicin was administered in combination with continuous infusions of amoxicillin, vancomycin, or penicillin against a bacterial biofilm adhering to glass beads. No significant differences in bacterial killing were found after 24 or 48 h between the once- and thrice-daily regimens. Additional experiments considering animal kinetics (half-life of netilmicin, 20 min) instead of human kinetics (half-life, 2.5 h) in the pharmacodynamic model also revealed similar results. The addition of netilmicin synergistically increased the activity of vancomycin (P < 0.05). In contrast, amoxicillin alone was as effective as the combination with netilmicin. Thus, it could not be established in this model that once-daily dosing of aminoglycosides is contraindicated for treating infections caused by E. faecalis.

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