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Sample records for humanized anti-vegf rabbit

  1. A Humanized Anti-VEGF Rabbit Monoclonal Antibody Inhibits Angiogenesis and Blocks Tumor Growth in Xenograft Models

    PubMed Central

    Zhang, Yongke; Yu, Qiu; Lee, Jonathan; Li, Mingzhen; Song, Jialiang; Chen, Jungang; Dai, Jihong; Couto, Fernando Jose Rebelo Do; An, Zhiqiang; Zhu, Weimin; Yu, Guo-Liang

    2010-01-01

    Rabbit antibodies have been widely used in research and diagnostics due to their high antigen specificity and affinity. Though these properties are also highly desirable for therapeutic applications, rabbit antibodies have remained untapped for human disease therapy. To evaluate the therapeutic potential of rabbit monoclonal antibodies (RabMAbs), we generated a panel of neutralizing RabMAbs against human vascular endothelial growth factor-A (VEGF). These neutralizing RabMAbs are specific to VEGF and do not cross-react to other members of the VEGF protein family. Guided by sequence and lineage analysis of a panel of neutralizing RabMAbs, we humanized the lead candidate by substituting non-critical residues with human residues within both the frameworks and the CDR regions. We showed that the humanized RabMAb retained its parental biological properties and showed potent inhibition of the growth of H460 lung carcinoma and A673 rhabdomyosarcoma xenografts in mice. These studies provide proof of principle for the feasibility of developing humanized RabMAbs as therapeutics. PMID:20140208

  2. Potent anti-angiogenesis and anti-tumor activity of a novel human anti-VEGF antibody, MIL60.

    PubMed

    Yang, Jing; Wang, Qun; Qiao, Chunxia; Lin, Zhou; Li, Xinying; Huang, Yifei; Zhou, Tingting; Li, Yan; Shen, Beifen; Lv, Ming; Feng, Jiannan

    2014-05-01

    Angiogenesis is crucial for tumor development, growth and metastasis. Vascular endothelial growth factor (VEGF) has been implicated in promoting solid tumor growth and metastasis via stimulating tumor-associated angiogenesis, and blocking the activity of VEGF can starve tumors. Avastin, which is a humanized anti-VEGF antibody, has been successfully applied in clinics since 2004. However, the price of Avastin is extremely high for Chinese people. Here, we report a novel human anti-VEGF neutralizing antibody, MIL60, which shows an affinity comparable to that of Avastin (the KD value of MIL60 was 44.5 pM, while that of Avastin was 42.7 pM). MIL60 displays favorable actions in inhibiting VEGF-triggered endothelial cell proliferation (the IC50 value of MIL60 was 31±6.4 ng/ml and that of Avastin was 47±8.1 ng/ml), migration (8 µg/ml or 0.8 µg/ml MIL60 versus the control: P<0.05) and tube formation (2 µg/ml or 0.2 µg/ml MIL60 versus the control: P<0.05) via the VEGFR2 signaling pathway. Moreover, MIL60 was shown to inhibit tumor growth and angiogenesis in vivo in xenograft models of human colon carcinoma and ovarian cancer using immunotherapy and immunohistochemistry analysis (MIL60 versus N.S.: P=0.0007; Avastin versus N.S.: P=0.00046). These data suggest that MIL60 is a potential therapeutic, anti-angiogenic agent. Our work provides a novel anti-VEGF antibody, which can be considered an anti-tumor antibody candidate and a new option for patients with various cancers. PMID:24608894

  3. Combination of anti-VEGF therapy and temozolomide in two experimental human glioma models.

    PubMed

    Grossman, Rachel; Brastianos, Harry; Blakeley, Jaishri O; Mangraviti, Antonella; Lal, Bachchu; Zadnik, Patti; Hwang, Lee; Wicks, Robert T; Goodwin, Rory C; Brem, Henry; Tyler, Betty

    2014-01-01

    Anti-angiogenic agents, such as bevacizumab (BEV), can induce normalization of the blood brain barrier, which may influence the penetration and activity of a co-administered cytotoxic drug. However, it is unknown whether this effect is associated with a benefit in overall survival. This study employed intracranial human glioma models to evaluate the effect of BEV alone and in combination with temozolomide (TMZ) and/or radiation therapy (XRT) on overall survival. One hundred eight male athymic rats were intracranially injected with either U251 or U87 human glioma. Ten or eleven days after tumor inoculation, animals bearing U251 and U87, respectively, were treated with: TMZ alone (50 mg/kg for 5 consecutive days, P.O.), BEV alone (15 mg/kg, I.V.), a combination of TMZ and BEV, or a combination of TMZ, BEV, and a single fraction of XRT (20 Gy). Controls received no treatment. The U87 experiment was repeated and the relationship between survival and the extent of anti-angiogenesis via anti-laminin antibodies for the detection of blood vessels was assessed. In both U87 glioma experiments, all of the treatment groups had a statistically significant increase in survival as compared to the control groups. Also, for both U87 experiments the combination groups of TMZ and BEV had significantly better survival when compared to either treatment administered alone, with 75% of animals demonstrating long-term survival (LTS) (defined as animals alive 120 days after tumor implantation) in one experiment and 25% LTS in the repeat experiment. In the U251 glioma experiment, all treated groups (except BEV alone) had significantly improved survival as compared to controls with minimal statistical variance among groups. The percent vessel area was lowest in the group of animals treated with BEV alone. The addition of BEV to TMZ and/or XRT had variable effect on prolonging survival in the two human glioma models tested with reduced tumor vascularity in groups treated with BEV. These

  4. Mechanism-Based Competitive Binding Model to Investigate the Effect of Neonatal Fc Receptor Binding Affinity on the Pharmacokinetic of Humanized Anti-VEGF Monoclonal IgG1 Antibody in Cynomolgus Monkey.

    PubMed

    Ng, Chee M; Fielder, Paul J; Jin, Jin; Deng, Rong

    2016-07-01

    The quantitative relationship between neonatal Fc receptor (FcRn) binding affinity at both acidic and physiological pH and the pharmacokinetics of protein engineered FcRn IgG1 variants has not yet been reported. Our objective was to develop a quantitatively mechanism-based competitive binding model to describe the effects of FcRn binding affinity at acidic and physiological pH on the pharmacokinetics of anti-VEGF IgG1 antibodies when both endogenous and exogenous antibodies are competing for the same FcRn. Pharmacokinetic (PK) and FcRn binding data from five Fc variants of humanized anti-VEGF IgG1 monoclonal antibodies with wide range of FcRn binding affinity were used for the analysis. Sixty-seven anti-VEGF IgG1 antibody-treated animals and 25 control animals with simulated endogenous IgG levels were used to develop the final model. A hybrid iterative two stages and Monte Carlo parametric expectation-maximization method was used to obtain the final model parameters estimates. The final model well described the observed PK data. Quantitative FcRn binding affinity-pharmacokinetics relationships was constructed to provide important biological insights in better understanding of the FcRn binding effect on pharmacokinetics of anti-VEGF IgG1 antibodies in cynomolgus monkeys and served as an important model-based drug discovery platform to guide the design and development of the future generation of anti-VEGF or other therapeutic IgG1 antibodies. PMID:27075465

  5. Using Anti-VEGF in Diabetic Retinopathy

    PubMed Central

    Marashi, Ameen

    2016-01-01

    Vascular endothelium growth factor is the main pathological factor in diabetic retinopathy and diabetic macular edema (DME), Anti-VEGF agents are safe and effective in DME treatment, there are multiple Anti-VEGF agents, choosing between them is essential to individualize treatment for each patient to achieve the optimum results. PMID:27419238

  6. Safety profiles of anti-VEGF drugs: bevacizumab, ranibizumab, aflibercept and ziv-aflibercept on human retinal pigment epithelium cells in culture

    PubMed Central

    Malik, Deepika; Tarek, Mohamed; Caceres del Carpio, Javier; Ramirez, Claudio; Boyer, David; Kenney, M Cristina; Kuppermann, Baruch D

    2014-01-01

    Purpose To compare the safety profiles of antivascular endothelial growth factor (VEGF) drugs ranibizumab, bevacizumab, aflibercept and ziv-aflibercept on retinal pigment epithelium cells in culture. Methods Human retinal pigment epithelium cells (ARPE-19) were exposed for 24 h to four anti-VEGF drugs at 1/2×, 1×, 2× and 10× clinical concentrations. Cell viability and mitochondrial membrane potential assay were performed to evaluate early apoptotic changes and rate of overall cell death. Results Cell viability decreased at 10× concentrations in bevacizumab (82.38%, p=0.0001), aflibercept (82.68%, p=0.0002) and ziv-aflibercept (77.25%, p<0.0001), but not at lower concentrations. However, no changes were seen in cell viability in ranibizumab-treated cells at all concentrations including 10×. Mitochondrial membrane potential was slightly decreased in 10× ranibizumab-treated cells (89.61%, p=0.0006) and 2× and 10× aflibercept-treated cells (88.76%, 81.46%; p<0.01, respectively). A larger reduction in mitochondrial membrane potential was seen at 1×, 2× and 10× concentrations of bevacizumab (86.53%, 74.38%, 66.67%; p<0.01) and ziv-aflibercept (73.50%, 64.83% and 49.65% p<0.01) suggestive of early apoptosis at lower doses, including the clinical doses. Conclusions At clinical doses, neither ranibizumab nor aflibercept produced evidence of mitochondrial toxicity or cell death. However, bevacizumab and ziv-aflibercept showed mild mitochondrial toxicity at clinically relevant doses. PMID:24836865

  7. Discontinuation of anti-VEGF cancer therapy promotes metastasis through a liver revascularization mechanism.

    PubMed

    Yang, Yunlong; Zhang, Yin; Iwamoto, Hideki; Hosaka, Kayoko; Seki, Takahiro; Andersson, Patrik; Lim, Sharon; Fischer, Carina; Nakamura, Masaki; Abe, Mitsuhiko; Cao, Renhai; Skov, Peter Vilhelm; Chen, Fang; Chen, Xiaoyun; Lu, Yongtian; Nie, Guohui; Cao, Yihai

    2016-01-01

    The impact of discontinuation of anti-VEGF cancer therapy in promoting cancer metastasis is unknown. Here we show discontinuation of anti-VEGF treatment creates a time-window of profound structural changes of liver sinusoidal vasculatures, exhibiting hyper-permeability and enlarged open-pore sizes of the fenestrated endothelium and loss of VE-cadherin. The drug cessation caused highly leaky hepatic vasculatures permit tumour cell intravasation and extravasation. Discontinuation of an anti-VEGF antibody-based drug and sunitinib markedly promotes liver metastasis. Mechanistically, host hepatocyte, but not tumour cell-derived vascular endothelial growth factor (VEGF), is responsible for cancer metastasis. Deletion of hepatocyte VEGF markedly ablates the 'off-drug'-induced metastasis. These findings provide mechanistic insights on anti-VEGF cessation-induced metastasis and raise a new challenge for uninterrupted and sustained antiangiogenic therapy for treatment of human cancers. PMID:27580750

  8. Anti-VEGF Therapies in the Clinic

    PubMed Central

    Meadows, Kellen L.; Hurwitz, Herbert I.

    2012-01-01

    The development and use of antiangiogenesis agents, particularly those targeting vascular endothelial growth factor (VEGF), has become an integral component of anticancer regimens for many tumor types. This review is intended to highlight some of the most important clinical successes and failures of anti-VEGF therapies, and where possible, to suggest important lessons that have been learned. This review emphasizes data from agents that have been FDA approved and/or have completed phase III studies. PMID:23028128

  9. Intravitreally Injected Anti-VEGF Antibody Reduces Brown Fat in Neonatal Mice

    PubMed Central

    Powner, Michael B.; Kim, Jin Hyoung; Fruttiger, Marcus; Kim, Jeong Hun

    2015-01-01

    Anti-vascular endothelial growth factor (VEGF) agents are the mainstay treatment for various angiogenesis-related retinal diseases. Currently, bevacizumab, a recombinant humanized anti-VEGF antibody, is trailed in retinopathy of prematurity, a vasoproliferative retinal disorder in premature infants. However, the risks of systemic complications after intravitreal injection of anti-VEGF antibody in infants are not well understood. In this study, we show that intravitreally injected anti-VEGF antibody is transported into the systemic circulation into the periphery where it reduces brown fat in neonatal C57BL/6 mice. A considerable amount of anti-VEGF antibody was detected in serum after intravitreal injection. Furthermore, in interscapular brown adipose tissue, we found lipid droplet accumulation, decreased VEGF levels, loss of vascular network, and decreased expression of mitochondria-related genes, Ppargc1a and Ucp1, all of which are characteristics of “whitening” of brown fat. With increasing age and body weight, brown fat restored its morphology and vascularity. Our results show that there is a transient, but significant impact of intravitreally administered anti-VEGF antibody on brown adipose tissue in neonatal mice. We suggest that more attention should be focused on the metabolic and developmental significance of brown adipose tissue in bevacizumab treated retinopathy of prematurity infants. PMID:26226015

  10. Intravitreally Injected Anti-VEGF Antibody Reduces Brown Fat in Neonatal Mice.

    PubMed

    Jo, Dong Hyun; Park, Sung Wook; Cho, Chang Sik; Powner, Michael B; Kim, Jin Hyoung; Fruttiger, Marcus; Kim, Jeong Hun

    2015-01-01

    Anti-vascular endothelial growth factor (VEGF) agents are the mainstay treatment for various angiogenesis-related retinal diseases. Currently, bevacizumab, a recombinant humanized anti-VEGF antibody, is trailed in retinopathy of prematurity, a vasoproliferative retinal disorder in premature infants. However, the risks of systemic complications after intravitreal injection of anti-VEGF antibody in infants are not well understood. In this study, we show that intravitreally injected anti-VEGF antibody is transported into the systemic circulation into the periphery where it reduces brown fat in neonatal C57BL/6 mice. A considerable amount of anti-VEGF antibody was detected in serum after intravitreal injection. Furthermore, in interscapular brown adipose tissue, we found lipid droplet accumulation, decreased VEGF levels, loss of vascular network, and decreased expression of mitochondria-related genes, Ppargc1a and Ucp1, all of which are characteristics of "whitening" of brown fat. With increasing age and body weight, brown fat restored its morphology and vascularity. Our results show that there is a transient, but significant impact of intravitreally administered anti-VEGF antibody on brown adipose tissue in neonatal mice. We suggest that more attention should be focused on the metabolic and developmental significance of brown adipose tissue in bevacizumab treated retinopathy of prematurity infants. PMID:26226015

  11. Angiogenesis in cancer: Anti-VEGF escape mechanisms

    PubMed Central

    Poettler, Marina; Unseld, Matthias; Zielinski, Christoph C.

    2012-01-01

    It is now widely accepted that tumor-angiogenesis plays a crucial role in tumor growth, tumor propagation and metastasis formation. Among several angiogenic activators, the vascular endothelial growth factor (VEGF) and its receptors represent one of the major inducers of tumor angiogenesis. Thus, this system has become the focus of therapeutic interventions, which led to the approval of the anti-VEGF blocking antibody bevacizumab and the VEGFR-2 pathway inhibitors pazopanib, sorafenib and sunitinib. However, not every cancer patient benefits from such treatment or finally becomes resistant to anti-VEGF approaches; others are suffering from adverse effects. Thus, there is an urgent need for a better understanding of VEGF-independent mechanisms leading to angiogenesis in cancer. This review focuses on anti-VEGF escape mechanisms of tumor cells and its microenvironment. PMID:25806151

  12. Anti-VEGF treatment improves neurological function and augments radiation response in NF2 schwannoma model

    PubMed Central

    Gao, Xing; Zhao, Yingchao; Stemmer-Rachamimov, Anat O.; Liu, Hao; Huang, Peigen; Chin, ShanMin; Selig, Martin K.; Plotkin, Scott R.; Jain, Rakesh K.; Xu, Lei

    2015-01-01

    Hearing loss is the main limitation of radiation therapy for vestibular schwannoma (VS), and identifying treatment options that minimize hearing loss are urgently needed. Treatment with bevacizumab is associated with tumor control and hearing improvement in neurofibromatosis type 2 (NF2) patients; however, its effect is not durable and its mechanism of action on nerve function is unknown. We modeled the effect anti-VEGF therapy on neurological function in the sciatic nerve model and found that it improves neurological function by alleviating tumor edema, which may further improve results by decreasing muscle atrophy and increasing nerve regeneration. Using a cranial window model, we showed that anti-VEGF treatment may achieve these effects via normalizing the tumor vasculature, improving vessel perfusion, and delivery of oxygenation. It is known that oxygen is a potent radiosensitizer; therefore, we further demonstrated that combining anti-VEGF with radiation therapy can achieve a better tumor control and help lower the radiation dose and, thus, minimize radiation-related neurological toxicity. Our results provide compelling rationale for testing combined therapy in human VS. PMID:26554010

  13. Development of a robust reporter-based assay for the bioactivity determination of anti-VEGF therapeutic antibodies.

    PubMed

    Wang, Lan; Xu, Gang-Ling; Gao, Kai; Wilkinson, Jennifer; Zhang, Feng; Yu, Lei; Liu, Chun-Yu; Yu, Chuan-Fei; Wang, Wen-Bo; Li, Meng; Chen, Wei; Fan, Frank; Cong, Mei; Wang, Jun-Zhi

    2016-06-01

    Development of anti-VEGF based biologic agents has been a focus in cancer treatment for the past decades, and several anti-VEGF pharmaceuticals have been already approved for treatment of various medical indications especially in cancer. The first anti-angiogenic agent approved by FDA was bevacizumab (BVZ, trade name Avastin, Genentech/Roche), a humanized anti-VEGF monoclonal antibody. Accurate determination of bioactivity is crucial for the safety and efficacy of therapeutic antibodies. The current method widely used in the lot release and stability test for clinical trial batches of BVZ is anti-proliferation assay using primary human umbilical vein endothelial cells (HUVEC), which is tedious with high assay variations. We describe here the development and preliminary validation of a reporter gene assay (RGA) that is based on an HEK293 cell line stably expressing vascular endothelial growth factor receptor 2 (VEGFR-2), and a luciferase reporter under the control of nuclear factor activated T cell (NFAT) response elements. Our study shows this assay not only to be superior on precision, sensitivity and assay simplicity compared with HUVEC assay, but also applicable to other VEGF-targeted biotherapeutics. These results show for the first time that this new reporter assay, based on the VEGF-VEGFR-NFAT pathway, can be a viable supplement to the HUVEC assay and employed in potency determination of BVZ and other kinds of anti-VEGF antibody-based biotherapeutics. PMID:27042807

  14. Tumor cell-derived placental growth factor sensitizes antiangiogenic and antitumor effects of anti-VEGF drugs

    PubMed Central

    Hedlund, Eva-Maria Eleonora; Yang, Xiaojuan; Zhang, Yin; Yang, Yunlong; Shibuya, Masabumi; Zhong, Weide; Sun, Baocun; Liu, Yizhi; Hosaka, Kayoko; Cao, Yihai

    2013-01-01

    The role of placental growth factor (PlGF) in modulation of tumor angiogenesis and tumor growth remains an enigma. Furthermore, anti-PlGF therapy in tumor angiogenesis and tumor growth remains controversial in preclinical tumor models. Here we show that in both human and mouse tumors, PlGF induced the formation of dilated and normalized vascular networks that were hypersensitive to anti-VEGF and anti–VEGFR-2 therapy, leading to dormancy of a substantial number of avascular tumors. Loss-of-function using plgf shRNA in a human choriocarcinoma significantly accelerated tumor growth rates and acquired resistance to anti-VEGF drugs, whereas gain-of-function of PlGF in a mouse tumor increased anti-VEGF sensitivity. Further, we show that VEGFR-2 and VEGFR-1 blocking antibodies displayed opposing effects on tumor angiogenesis. VEGFR-1 blockade and genetic deletion of the tyrosine kinase domain of VEGFR-1 resulted in enhanced tumor angiogenesis. These findings demonstrate that tumor-derived PlGF negatively modulates tumor angiogenesis and tumor growth and may potentially serve as a predictive marker of anti-VEGF cancer therapy. PMID:23267058

  15. Defining response to anti-VEGF therapies in neovascular AMD

    PubMed Central

    Amoaku, W M; Chakravarthy, U; Gale, R; Gavin, M; Ghanchi, F; Gibson, J; Harding, S; Johnston, R L; Kelly, S; Lotery, A; Mahmood, S; Menon, G; Sivaprasad, S; Talks, J; Tufail, A; Yang, Y

    2015-01-01

    The introduction of anti-vascular endothelial growth factor (anti-VEGF) has made significant impact on the reduction of the visual loss due to neovascular age-related macular degeneration (n-AMD). There are significant inter-individual differences in response to an anti-VEGF agent, made more complex by the availability of multiple anti-VEGF agents with different molecular configurations. The response to anti-VEGF therapy have been found to be dependent on a variety of factors including patient's age, lesion characteristics, lesion duration, baseline visual acuity (VA) and the presence of particular genotype risk alleles. Furthermore, a proportion of eyes with n-AMD show a decline in acuity or morphology, despite therapy or require very frequent re-treatment. There is currently no consensus as to how to classify optimal response, or lack of it, with these therapies. There is, in particular, confusion over terms such as ‘responder status' after treatment for n-AMD, ‘tachyphylaxis' and ‘recalcitrant' n-AMD. This document aims to provide a consensus on definition/categorisation of the response of n-AMD to anti-VEGF therapies and on the time points at which response to treatment should be determined. Primary response is best determined at 1 month following the last initiation dose, while maintained treatment (secondary) response is determined any time after the 4th visit. In a particular eye, secondary responses do not mirror and cannot be predicted from that in the primary phase. Morphological and functional responses to anti-VEGF treatments, do not necessarily correlate, and may be dissociated in an individual eye. Furthermore, there is a ceiling effect that can negate the currently used functional metrics such as >5 letters improvement when the baseline VA is good (ETDRS>70 letters). It is therefore important to use a combination of both the parameters in determining the response.The following are proposed definitions: optimal (good) response is defined as when

  16. Corneal Neovascularization: An Anti-VEGF Therapy Review

    PubMed Central

    Chang, Jin-Hong; Garg, Nitin K.; Lunde, Elisa; Han, Kyu-Yeon; Jain, Sandeep; Azar, Dimitri T.

    2013-01-01

    Corneal neovascularization is a serious condition that can lead to a profound decline in vision. The abnormal vessels block light, cause corneal scarring, compromise visual acuity, and may lead to inflammation and edema. Corneal neovascularization occurs when the balance between angiogenic and antiangiogenic factors is tipped toward angiogenic molecules. Vascular endothelial growth factor (VEGF), one of the most important mediators of angiogenesis, is upregulated during neovascularization. In fact, anti-VEGF agents have efficacy in the treatment of neovascular age-related macular degeneration, diabetic retinopathy, macular edema, neovascular glaucoma, and other neovascular diseases. These same agents have great potential for the treatment of corneal neovascularization. We review some of the most promising anti-VEGF therapies, including bevacizumab, VEGF trap, siRNA, and tyrosine kinase inhibitors. PMID:22898649

  17. Anti-VEGF Therapy and the Retina: An Update

    PubMed Central

    Tah, Vikas; Orlans, Harry O.; Hyer, Jonathan; Casswell, Edward; Din, Nizar; Sri Shanmuganathan, Vishnu; Ramskold, Louise; Pasu, Saruban

    2015-01-01

    Ocular angiogenesis and macular oedema are major causes of sight loss across the world. Aberrant neovascularisation, which may arise secondary to numerous disease processes, can result in reduced vision as a result of oedema, haemorrhage, and scarring. The development of antivascular endothelial growth factor (anti-VEGF) agents has revolutionised the treatment of retinal vasogenic conditions. These drugs are now commonly employed for the treatment of a plethora of ocular pathologies including choroidal neovascularisation, diabetic macular oedema, and retinal vein occlusion to name a few. In this paper, we will explore the current use of anti-VEGF in a variety of retinal diseases and the impact that these medications have had on visual outcome for patients. PMID:26417453

  18. Anti-VEGF antibody treatment accelerates polycystic kidney disease.

    PubMed

    Raina, Shagun; Honer, Michael; Krämer, Stefanie D; Liu, Yang; Wang, Xueqi; Segerer, Stephan; Wüthrich, Rudolf P; Serra, Andreas L

    2011-10-01

    Polycystic kidney growth implies expansion of the vasculature, suggesting that vascular endothelial growth factor (VEGF)-dependent processes play a critical role and that VEGF is a putative therapeutic target. Whether an anti-VEGF antibody improves renal cystic disease has not been determined. We administrated 5 mg/kg B20.4.1, an anti-VEGF-A antibody, or vehicle intraperitoneally twice weekly to 4-wk-old male normal (+/+) and cystic (Cy/+) Han:SPRD rats for 6 wk. Renal function, urinary protein excretion, organ/body weight ratios, cyst volume, tubular epithelial cell (TEC) proliferation, renal VEGF, hypoxia-inducible factor (HIF)-1α and -2α expression, renal histology, and kidney hypoxia visualized by [(18)F]fluoromisonidazole positron emission tomography were assessed. The treated compared with untreated +/+ rats had lower TEC proliferation rates, whereas Cy/+ rats receiving B20.4.1 displayed an increased proximal TEC proliferation rate, causing enhanced cyst and kidney growth. The +/+ and Cy/+ rats receiving B20.4.1 had severe renal failure and extensive glomerular damage. Proteinuria, which was highest in anti-VEGF-treated Cy/+ and lowest in untreated normal littermates, was positively correlated with renal HIF-1α and negatively correlated with VEGF expression. The untreated Cy/+ vs. +/+ rats had higher overall [(18)F]fluoromisonidazole uptake. The +/+ rats receiving B20.4.1 vs. untreated had increased [(18)F]fluoromisonidazole uptake, whereas the uptake was unchanged among treated vs. untreated Cy/+ animals. In conclusion, B20.4.1 caused an exaggerated cystic response of the proximal tubules in cystic rats and severe kidney injury that was associated with low renal VEGF and high HIF-1α levels. Anti-VEGF drug therapy may therefore not be a treatment option for polycystic kidney disease. PMID:21677148

  19. [Chances and risks of anti-VEGF therapy].

    PubMed

    Ziemssen, F; Heiduschka, P; Peters, S; Grisanti, S; Schraermeyer, U

    2008-09-01

    Vascular endothelial growth factor (VEGF) plays a pivotal role in angiogenesis. Through regulation of haemodynamics, haematopoesis and the immune system, endocrinology and reparative processes, inhibition of VEGF can cause multiple adverse events. Previous data suggest that--even after intravitreal injection--systemic exposure might occur, thus bearing the risk of manifestation of side effects. Experience with intravenous administration of the antibody bevacizumab (Avastin) pointed to the potential consequences of a pan-VEGF blockade. The change of haemodynamic parameters implies a potential influence on the patient's morbidity. Studies already conducted during the approval process do not provide sufficient statistical power when evaluating whether systemic events significantly differ between the treatment and control groups. Retinal perfusion showed an altered vascular tone (change in vessel diameter) following anti-VEGF treatment. Physiological fenestration of the choroicapillaris is significantly reduced. Possible effects on the local oxygen supply in ischaemic tissue have to be considered. In contrast to destructive treatment modalities (laser, cryo), VEGF inhibitors promise the prompt and efficient response of retinal neovascularisation and the preservation of a better function (visual fields). The maturation of growing vessels (pericytes) and the secondary formation of membranes are limiting factors with regard to the time-point at which anti-VEGF therapy is most effective. A diligent use of the available drugs has to take into account which types of exudative retinopathy are showing no or only very limited response to the treatment. PMID:18759208

  20. Moving Past Anti-VEGF: Novel Therapies for Treating Diabetic Retinopathy.

    PubMed

    Bolinger, Mark T; Antonetti, David A

    2016-01-01

    Diabetic retinopathy is the leading cause of blindness in working age adults, and is projected to be a significant future health concern due to the rising incidence of diabetes. The recent advent of anti-vascular endothelial growth factor (VEGF) antibodies has revolutionized the treatment of diabetic retinopathy but a significant subset of patients fail to respond to treatment. Accumulating evidence indicates that inflammatory cytokines and chemokines other than VEGF may contribute to the disease process. The current review examines the presence of non-VEGF cytokines in the eyes of patients with diabetic retinopathy and highlights mechanistic pathways in relevant animal models. Finally, novel drug targets including components of the kinin-kallikrein system and emerging treatments such as anti-HPTP (human protein tyrosine phosphatase) β antibodies are discussed. Recognition of non-VEGF contributions to disease pathogenesis may lead to novel therapeutics to enhance existing treatments for patients who do not respond to anti-VEGF therapies. PMID:27618014

  1. A review of anti-VEGF agents for proliferative diabetic retinopathy

    PubMed Central

    Osaadon, P; Fagan, X J; Lifshitz, T; Levy, J

    2014-01-01

    Previous research has implicated vascular endothelial growth factor (VEGF) in the pathogenesis of diabetic retinopathy (DR). Although many studies reviewed the use of anti-VEGF for diabetic macular oedema, little has been written about the use of anti-VEGF for proliferative diabetic retinopathy (PDR). This study is a review of relevant publications dealing with the use of anti-VEGF for the treatment of PDR. The articles were identified through systematic searches of PUBMED and the Cochrane Central Register of Controlled Trials. At the end of each section, we summarized the level of evidence of the scientific literature. Off-label use of anti-VEGF agents was found to be beneficial in PDR, especially in cases with neovascular glaucoma, persistent vitreous haemorrhage, and before vitrectomy. The disadvantages of the use of anti-VEGF are its short-effect duration, causing tractional retinal detachment in cases with pre-existing pre-retinal fibrosis and endophthalmitis in rare cases. There is no conclusive evidence from large randomized trials regarding the efficacy of anti-VEGF treatment in PDR. However, numerous case series, sound biochemical mechanism of action, and increasing experience with using anti-VEGF drugs can be used to support the ongoing use of this treatment modality in selected patients. PMID:24525867

  2. What is the risk of intracranial bleeding during anti-VEGF therapy?

    PubMed

    Carden, Craig P; Larkin, James M G; Rosenthal, Mark A

    2008-08-01

    Vascular endothelial growth factor (VEGF) is a key mediator of physiological and pathological angiogenesis. All solid tumors are dependent on pathological angiogenesis, and anti-VEGF therapy has demonstrated clinical benefit in breast, colorectal, non-small-cell lung, and renal carcinomas. Central nervous system metastases are common in many of these tumor types. An increased risk of bleeding has been reported with anti-VEGF therapy, but the risk of intracranial bleeding is unknown with this type of therapy. We reviewed the available data to investigate the risk of intracranial bleeding with anti-VEGF therapy in the presence and absence of CNS metastases. The PubMed and Medline databases and the Proceedings of the American Society of Clinical Oncology (ASCO) annual meetings were searched for articles, abstracts, and presentations of clinical trials. We identified 57 trials examining the safety and efficacy of anti-VEGF therapy in a total of 10,598 patients. Four trials examined the use of anti-VEGF therapy in treating patients with brain metastases. The presence of CNS metastases was a stated exclusion criterion in 76% of trials. The rate of intracranial bleeding was negligible. We conclude that there is no trial evidence that anti-VEGF therapy confers an increased risk of intracranial bleeding, even in the presence of CNS metastases. Future trials of anti-VEGF therapy should not exclude patients with controlled CNS metastases at enrollment. PMID:18539884

  3. Vaccination with a mutated variant of human Vascular Endothelial Growth Factor (VEGF) blocks VEGF-induced retinal neovascularization in a rabbit experimental model.

    PubMed

    Morera, Yanelys; González, Rafael; Lamdan, Humberto; Pérez, Lincidio; González, Yorlandis; Agüero, Judith; Castro, Jorge; Romero, Juan C; Etchegoyen, Ana Yansy; Ayala, Marta; Gavilondo, Jorge V

    2014-05-01

    Vascular Endothelial Growth Factor (VEGF) is a key driver of the neovascularization and vascular permeability that leads to the loss of visual acuity of eye diseases like wet age-related macular degeneration, diabetic macular edema, and retinopathy of premature. Among the several anti-VEGF therapies under investigation for the treatment of neovascular eye diseases, our group has developed the vaccine candidate CIGB-247-V that uses a mutated form of human VEGF as antigen. In this work we evaluated if the vaccine could prevent or attenuate VEGF-induced retinal neovascularization in the course of a rabbit eye neovascularization model, based on direct intravitreal injection of human VEGF. Our experimental findings have shown that anti-VEGF IgG antibodies induced by the vaccine were available in the retina blood circulation, and could neutralize in situ the neovascularization effect of VEGF. CIGB-247-V vaccination proved to effectively reduce retinal neovascularization caused by intravitreal VEGF injection. Altogether, these results open the way for human studies of the vaccine in neovascular eye syndromes, and inform on the potential mechanisms involved in its effect. PMID:24675387

  4. Anti-VEGF Treatment Resistant Pancreatic Cancers Secrete Proinflammatory Factors that Contribute to Malignant Progression by Inducing an EMT cell phenotype

    PubMed Central

    Carbone, Carmine; Moccia, Tania; Zhu, Cihui; Paradiso, Genni; Budillon, Alfredo; Chiao, Paul J.; Abbruzzese, James L.; Melisi, Davide

    2011-01-01

    Purpose The resistance of tumors to antiangiogenic therapies is becoming increasingly relevant. There are currently no validated predictive biomarkers for selecting which cancer patients will benefit from antiangiogenic therapy. Also lacking are resistance biomarkers that can identify which escape pathways should be targeted after tumors develop resistance to anti-vascular endothelial growth factor (VEGF) treatment. Recent studies showed that anti-VEGF treatment can make tumor cells more aggressive and metastatic. However, the mechanisms and mediators of this are unidentified. Therefore, we aimed the present study at directly identifying the tumor cell-initiated mechanisms responsible for the resistance of pancreatic cancer to anti-VEGF treatment. Experimental design We established and validated two murine models of human pancreatic cancer resistant to the VEGF-specific antibody bevacizumab in vivo. We used a genome-wide analysis to directly identify which tumor-secreted factors were overexpressed by pancreatic cancer cells that were resistant to anti-VEGF treatment. Results Rather then direct proangiogenic factors, we identified several proinflammatory factors that were expressed at higher levels in cells resistant to anti-VEGF treatment than in treatment-sensitive control cells. These proinflammatory factors acted in a paracrine manner to stimulate the recruitment of CD11b+ proangiogenic myeloid cells. Also, we found that secreted factors overexpressed by anti-VEGF treatment-resistant pancreatic cancer cells acted in an autocrine manner to induce epithelial- to- mesenchymal transition (EMT) and were thus responsible for increased aggressiveness of bevacizumab-resistant pancreatic tumors. Conclusions Our results identified proinflammatory factors and EMT markers as potential biomarkers for selecting patients with pancreatic cancer for antiangiogenic therapy. PMID:21737511

  5. Method development to quantify Bv8 expression in circulating CD11b+ cells in patients with neovascular age-related macular degeneration (nvAMD) exhibiting Anti-VEGF refractoriness.

    PubMed

    Catchpole, Timothy; Daniels, Tad; Perkins, Jill; Csaky, Karl G

    2016-07-01

    A subset of neovascular age-related macular degeneration (nvAMD) subjects appears to be refractory to the effects of anti-VEGF treatment and require frequent intravitreal injections. Prokineticin-2 (Bv8) expression in CD11b(+) cells has been linked to anti-VEGF response. We have developed a reproducible method to quantify gene expression in circulating CD11b + cells. Utilizing this method we tested the hypothesis that high Bv8 expression in circulating CD11b(+) cells is associated with anti-VEGF refractoriness in nvAMD patients. Two groups of nvAMD subjects undergoing treatment with anti-VEGF agents were recruited and classified as refractory or non-refractory to anti-VEGF treatment (n = 33 for each group). Two blood draws were obtained from each subject 1-9 months apart. Peripheral blood mononuclear cells (PBMCs) were isolated and CD11b(+) cells were purified via magnetic bead separation. RNA was purified, and relative expression of Bv8 among the subjects was compared via quantitative PCR analysis. Utilizing this approach no significant difference was detected in the mean LogRQ values between the first and second blood draws (t-test, p = 0.826) indicating low intra-patient variability and demonstrating good reproducibility of the assay. There was no significant difference in Bv8 expression between nvAMD subjects classified as refractory versus non-refractory. We were unable to find a correlation between Bv8 expression in CD11b + cells and anti-VEGF refractoriness in human nvAMD subjects. Relatively high expression in Bv8 in these subjects did not correlate with clinical treatment history, as measured by the frequency of injections. Utilizing this well characterized technique, studies are underway to examine alternative gene expression profiles in various circulating cell populations that may contribute to anti-VEGF refractoriness. PMID:27256991

  6. Pharmacokinetic and Pharmacodynamic Properties of Anti-VEGF Drugs After Intravitreal Injection.

    PubMed

    Semeraro, Francesco; Morescalchi, Francesco; Duse, Sarah; Gambicorti, Elena; Cancarini, Anna; Costagliola, Ciro

    2015-01-01

    Subretinal neovascularization and pathologic ocular angiogenesis are common causes of progressive, irreversible impairment of central vision, and dramatically affect quality of life. Anti-vascular endothelial growth factor (anti-VEGF) therapy has improved the quality of life for many patients with age-related macular degeneration, diabetic retinopathy, and other ocular diseases involving neovascularization and edema. In these pathologies, the inhibition of intraocular VEGF is the only therapy that can preserve vision. Four anti-VEGF drugs are currently used to treat ocular neovascularization; pegaptanib, ranibizumab, and aflibercept have been approved for this condition, while bevacizumab can be used off-label. Anti-VEGF therapy is administered regularly for many months or years because its suspension or discontinuation may cause recurrence of neovascularization. On the other hand, VEGF is necessary for the survival of retinal and choroidal endothelial cells. Experimental studies in animal models have shown that local inhibition of VEGF causes thinning and atrophy of the choriocapillaris and degeneration of photoreceptors, primarily cones. These studies combined with clinical experience indicated that prolonged VEGF inhibition could impair retinal function. Moreover, anti-VEGF compounds can cross the blood-retina barrier, enter the systemic circulation, and inhibit serum VEGF. Since circulating VEGF protects blood vessel integrity, prolonged anti-VEGF treatment could induce thromboembolic adverse events from vascular causes such as heart attack and stroke, and even death. The ocular dosing regimen and systemic toxicity of anti-VEGF compounds are therefore central concerns. A better understanding of this topic requires knowledge of the metabolism, tissue distribution, and clearance of anti-VEGF compounds. This manuscript reviews the properties of anti-VEGF compounds following intravitreal administration. PMID:26424177

  7. Endocrine vasculatures are preferable targets of an antitumor ineffective low dose of anti-VEGF therapy.

    PubMed

    Zhang, Yin; Yang, Yunlong; Hosaka, Kayoko; Huang, Guichun; Zang, Jingwu; Chen, Fang; Zhang, Yun; Samani, Nilesh J; Cao, Yihai

    2016-04-12

    Anti-VEGF-based antiangiogenic drugs are designed to block tumor angiogenesis for treatment of cancer patients. However, anti-VEGF drugs produce off-tumor target effects on multiple tissues and organs and cause broad adverse effects. Here, we show that vasculatures in endocrine organs were more sensitive to anti-VEGF treatment than tumor vasculatures. In thyroid, adrenal glands, and pancreatic islets, systemic treatment with low doses of an anti-VEGF neutralizing antibody caused marked vascular regression, whereas tumor vessels remained unaffected. Additionally, a low dose of VEGF blockade significantly inhibited the formation of thyroid vascular fenestrae, leaving tumor vascular structures unchanged. Along with vascular structural changes, the low dose of VEGF blockade inhibited vascular perfusion and permeability in thyroid, but not in tumors. Prolonged treatment with the low-dose VEGF blockade caused hypertension and significantly decreased circulating levels of thyroid hormone free-T3 and -T4, leading to functional impairment of thyroid. These findings show that the fenestrated microvasculatures in endocrine organs are more sensitive than tumor vasculatures in response to systemic anti-VEGF drugs. Thus, our data support the notion that clinically nonbeneficial treatments with anti-VEGF drugs could potentially cause adverse effects. PMID:27035988

  8. Anti-VEGF treatment for myopic choroid neovascularization: from molecular characterization to update on clinical application

    PubMed Central

    Zhang, Yan; Han, Qian; Ru, Yusha; Bo, Qiyu; Wei, Rui Hua

    2015-01-01

    Choroidal neovascularization (CNV) secondary to pathologic myopia has a very high incidence in global, especially in Asian, populations. It is a common cause of irreversible central vision loss, and severely affects the quality of life in the patients with pathologic myopia. The traditional therapeutic modalities for CNV secondary to pathologic myopia include thermal laser photocoagulation, surgical management, transpupillary thermotherapy, and photodynamic therapy with verteporfin. However, the long-term outcomes of these modalities are disappointing. Recently, intravitreal administration of anti-VEGF biological agents, including bevacizumab, ranibizumab, pegaptanib, aflibercept, and conbercept, has demonstrated promising outcomes for this ocular disease. The anti-VEGF regimens are more effective on improving visual acuity, reducing central fundus thickness and central retina thickness than the traditional modalities. These anti-VEGF agents thus hold the potential to become the first-line medicine for treatment of CNV secondary to pathologic myopia. This review follows the trend of “from bench to bedside”, initially discussing the pathogenesis of myopic CNV, delineating the molecular structures and mechanisms of action of the currently available anti-VEGF drugs, and then systematically comparing the up to date clinical applications as well as the efficacy and safety of the anti-VEGF drugs to the CNV secondary to pathologic myopia. PMID:26170626

  9. Intravitreal injection of anti-VEGF and diagnosis of primary intraocular central nervous system lymphoma.

    PubMed

    Gambrelle, J; Missotten, G; Delhoum, S; Desjardins, L

    2013-05-01

    We report a case of primary intraocular central nervous system (CNS) lymphoma in a patient previously treated with intravitreal anti-vascular endothelial growth factor (VEGF) injections for age-related macular degeneration (AMD). An 88-year-old woman, with past medical history significant for bilateral age-related macular degeneration (AMD) treated with intravitreal ranibizumab injections for 1 year, was referred to our department for bilateral vitritis diagnosed 10 days after the last anti-VEGF injection. A complete uveitis work-up including aqueous humour analysis, brain MRI and vitreous biopsy enabled us to confirm the diagnosis of primary intraocular CNS lymphoma. To the best of our knowledge, this is the first report of the diagnosis of primary intraocular CNS lymphoma in a patient treated with anti-VEGF for AMD. The differential diagnosis of vitritis in elderly patients is relatively broad. Endophthalmitis and uveitis have been described after anti-VEGF injections. In such a situation, there is actually a risk of missing the diagnosis of intraocular lymphoma in the mistaken belief that the observed vitritis may be a reaction to administered anti-VEGFs. If no direct time-relationship with the anti-VEGF injections can be found, a classic vitritis work-up should be performed. Our observation suggests that ranibizumab, at the dosage used for AMD, does not impede the spread of CNS lymphoma in the eye nor interfere with cytological diagnosis. PMID:23306179

  10. Anti-VEGF treatment for myopic choroid neovascularization: from molecular characterization to update on clinical application.

    PubMed

    Zhang, Yan; Han, Qian; Ru, Yusha; Bo, Qiyu; Wei, Rui Hua

    2015-01-01

    Choroidal neovascularization (CNV) secondary to pathologic myopia has a very high incidence in global, especially in Asian, populations. It is a common cause of irreversible central vision loss, and severely affects the quality of life in the patients with pathologic myopia. The traditional therapeutic modalities for CNV secondary to pathologic myopia include thermal laser photocoagulation, surgical management, transpupillary thermotherapy, and photodynamic therapy with verteporfin. However, the long-term outcomes of these modalities are disappointing. Recently, intravitreal administration of anti-VEGF biological agents, including bevacizumab, ranibizumab, pegaptanib, aflibercept, and conbercept, has demonstrated promising outcomes for this ocular disease. The anti-VEGF regimens are more effective on improving visual acuity, reducing central fundus thickness and central retina thickness than the traditional modalities. These anti-VEGF agents thus hold the potential to become the first-line medicine for treatment of CNV secondary to pathologic myopia. This review follows the trend of "from bench to bedside", initially discussing the pathogenesis of myopic CNV, delineating the molecular structures and mechanisms of action of the currently available anti-VEGF drugs, and then systematically comparing the up to date clinical applications as well as the efficacy and safety of the anti-VEGF drugs to the CNV secondary to pathologic myopia. PMID:26170626

  11. Rabbit Models for Studying Human Infectious Diseases

    PubMed Central

    Peng, Xuwen; Knouse, John A; Hernon, Krista M

    2015-01-01

    Using an appropriate animal model is crucial for mimicking human disease conditions, and various facets including genetics, anatomy, and pathophysiology should be considered before selecting a model. Rabbits (Oryctolagus cuniculus) are well known for their wide use in production of antibodies, eye research, atherosclerosis and other cardiovascular diseases. However, a systematic description of the rabbit as primary experimental models for the study of various human infectious diseases is unavailable. This review focuses on the human infectious diseases for which rabbits are considered a classic or highly appropriate model, including AIDS (caused by HIV1), adult T-cell leukemia–lymphoma (human T-lymphotropic virus type 1), papilloma or carcinoma (human papillomavirus) , herpetic stromal keratitis (herpes simplex virus type 1), tuberculosis (Mycobacterium tuberculosis), and syphilis (Treponema pallidum). In addition, particular aspects of the husbandry and care of rabbits used in studies of human infectious diseases are described. PMID:26678367

  12. Rabbit Models for Studying Human Infectious Diseases.

    PubMed

    Peng, Xuwen; Knouse, John A; Hernon, Krista M

    2015-12-01

    Using an appropriate animal model is crucial for mimicking human disease conditions, and various facets including genetics, anatomy, and pathophysiology should be considered before selecting a model. Rabbits (Oryctolagus cuniculus) are well known for their wide use in production of antibodies, eye research, atherosclerosis and other cardiovascular diseases. However, a systematic description of the rabbit as primary experimental models for the study of various human infectious diseases is unavailable. This review focuses on the human infectious diseases for which rabbits are considered a classic or highly appropriate model, including AIDS (caused by HIV1), adult T-cell leukemia-lymphoma (human T-lymphotropic virus type 1), papilloma or carcinoma (human papillomavirus) , herpetic stromal keratitis (herpes simplex virus type 1), tuberculosis (Mycobacterium tuberculosis), and syphilis (Treponema pallidum). In addition, particular aspects of the husbandry and care of rabbits used in studies of human infectious diseases are described. PMID:26678367

  13. Association of Anti-VEGF Injections with Progression of Geographic Atrophy

    PubMed Central

    Enslow, Ryan; Bhuvanagiri, Sai; Vegunta, Sravanthi; Cutler, Benjamin; Neff, Michael; Stagg, Brian

    2016-01-01

    Age-related macular degeneration (AMD) is one of the leading causes of blindness in developed countries in people over the age of 60 years. One of the forms of advanced AMD is wet AMD. Wet AMD is a result of leakage and bleeding from abnormal neovascularization. The principal treatment for wet AMD is intravitreal anti-VEGF injections. A second form of advanced AMD is geographic atrophy (GA). GA refers to large areas of retinal pigment epithelium loss. In the literature, there is some concern that anti-VEGF injections administered to treat wet AMD may be associated with progression of GA. This review discusses evidence suggesting the association of anti-VEGF injections with progression of GA. PMID:27528805

  14. Association of Anti-VEGF Injections with Progression of Geographic Atrophy.

    PubMed

    Enslow, Ryan; Bhuvanagiri, Sai; Vegunta, Sravanthi; Cutler, Benjamin; Neff, Michael; Stagg, Brian

    2016-01-01

    Age-related macular degeneration (AMD) is one of the leading causes of blindness in developed countries in people over the age of 60 years. One of the forms of advanced AMD is wet AMD. Wet AMD is a result of leakage and bleeding from abnormal neovascularization. The principal treatment for wet AMD is intravitreal anti-VEGF injections. A second form of advanced AMD is geographic atrophy (GA). GA refers to large areas of retinal pigment epithelium loss. In the literature, there is some concern that anti-VEGF injections administered to treat wet AMD may be associated with progression of GA. This review discusses evidence suggesting the association of anti-VEGF injections with progression of GA. PMID:27528805

  15. Resistance to anti-VEGF therapy in neovascular age-related macular degeneration: a comprehensive review

    PubMed Central

    Yang, Shiqi; Zhao, Jingke; Sun, Xiaodong

    2016-01-01

    As a progressive chronic disease, age-related macular degeneration (AMD) is the leading cause of irreversible vision impairment worldwide. Experimental and clinical evidence has demonstrated that vascular endothelial growth factor (VEGF) plays a vital role in the formation of choroidal neovascularization. Intravitreal injections of anti-VEGF agents have been recommended as a first-line treatment for neovascular AMD. However, persistent fluid or recurrent exudation still occurs despite standardized anti-VEGF therapy. Patients suffering from refractory or recurrent neovascular AMD may develop mechanisms of resistance to anti-VEGF therapy, which results in a diminished therapeutic effect. Until now, there has been no consensus on the definitions of refractory neovascular AMD and recurrent neovascular AMD. This article aims at clarifying these concepts to evaluate the efficacy of switching drugs, which contributes to making clinical decision more scientifically. Furthermore, insight into the causes of resistance to anti-VEGF therapy would be helpful for developing possible therapeutic approaches, such as combination therapy and multi-target treatment that can overcome this resistance. PMID:27330279

  16. The Application of OCTA in Assessment of Anti-VEGF Therapy for Idiopathic Choroidal Neovascularization

    PubMed Central

    Sun, Zihan; Dai, Hong

    2016-01-01

    Purpose. To assess the morphology of idiopathic choroidal neovascularization (ICNV) by optical coherence tomography angiography (OCTA) and determine the therapeutic effects of intravitreal antivascular endothelial growth factor (anti-VEGF). Method. Patients with naive ICNV were assessed by spectral domain optical coherence tomography (SD-OCT) and OCTA in this observational study. The timing of observation was before treatment, 1 day after treatment with intravitreal anti-VEGF injection, and 1 month after the treatment. The central retina thickness (CRT) on SD-OCT, selected CNV area, and flow area on OCTA were measured. Results. A total of 17 eyes from 17 patients with ICNV were included in this study. OCTA showed visible irregular choroidal neovascularization with “tree-in-bud” form on outer retinal layer. After treatment, as well as in the 1-day follow-up, CNV decreased in size from the periphery, and the vessel density was reduced. As shown on OCTA, the selected CNV area and flow area were significantly reduced compared to pretreatment. The rate of CNV vessel area changes was higher on OCTA than the changes in CRT on SD-OCT at 1-day and 1-month follow-up. Conclusion. Intravitreal injection of anti-VEGF is effective for idiopathic choroidal neovascularization, and the treatment outcomes are observable after 1 day. OCTA provides a useful approach for monitoring and evaluating the treatment of intravitreal anti-VEGF for CNV. PMID:27471600

  17. The Application of OCTA in Assessment of Anti-VEGF Therapy for Idiopathic Choroidal Neovascularization.

    PubMed

    Chen, Qin; Yu, Xiaobing; Sun, Zihan; Dai, Hong

    2016-01-01

    Purpose. To assess the morphology of idiopathic choroidal neovascularization (ICNV) by optical coherence tomography angiography (OCTA) and determine the therapeutic effects of intravitreal antivascular endothelial growth factor (anti-VEGF). Method. Patients with naive ICNV were assessed by spectral domain optical coherence tomography (SD-OCT) and OCTA in this observational study. The timing of observation was before treatment, 1 day after treatment with intravitreal anti-VEGF injection, and 1 month after the treatment. The central retina thickness (CRT) on SD-OCT, selected CNV area, and flow area on OCTA were measured. Results. A total of 17 eyes from 17 patients with ICNV were included in this study. OCTA showed visible irregular choroidal neovascularization with "tree-in-bud" form on outer retinal layer. After treatment, as well as in the 1-day follow-up, CNV decreased in size from the periphery, and the vessel density was reduced. As shown on OCTA, the selected CNV area and flow area were significantly reduced compared to pretreatment. The rate of CNV vessel area changes was higher on OCTA than the changes in CRT on SD-OCT at 1-day and 1-month follow-up. Conclusion. Intravitreal injection of anti-VEGF is effective for idiopathic choroidal neovascularization, and the treatment outcomes are observable after 1 day. OCTA provides a useful approach for monitoring and evaluating the treatment of intravitreal anti-VEGF for CNV. PMID:27471600

  18. Diffusion of anti-VEGF injections in the Portuguese National Health System

    PubMed Central

    Marques, Ana Patrícia; Macedo, António Filipe; Perelman, Julian; Aguiar, Pedro; Rocha-Sousa, Amândio; Santana, Rui

    2015-01-01

    Objectives To analyse the temporal and geographical diffusion of antivascular endothelial growth factor (anti-VEGF) interventions, and its determinants in a National Health System (NHS). Setting NHS Portuguese hospitals. Participants All inpatient and day cases related to eye diseases at all Portuguese public hospitals for the period 2002–2012 were selected on the basis of four International Classification of Diseases 9th revision, Clinical Modification (ICD-9-CM) codes for procedures: 1474, 1475, 1479 and 149. Primary and secondary outcome measures We measured anti-VEGF treatment rates by year and county. The determinants of the geographical diffusion were investigated using generalised linear modelling. Results We analysed all hospital discharges from all NHS hospitals in Portugal (98 408 hospital discharges corresponding to 57 984 patients). National rates of hospitals episodes for the codes for procedures used were low before anti-VEGF approval in 2007 (less than 12% of hospital discharges). Between 2007 and 2012, the rates of hospital episodes related to the introduction of anti-VEGF injections increased by 27% per year. Patients from areas without ophthalmology departments received fewer treatments than those from areas with ophthalmology departments. The availability of an ophthalmology department in the county increased the rates of hospital episodes by 243%, and a 100-persons greater density per km2 raised the rates by 11%. Conclusions Our study shows a large but unequal diffusion of anti-VEGF treatments despite the universal coverage and very low copayments. The technological innovation in ophthalmology may thus produce unexpected inequalities related to financial constraints unless the implementation of innovative techniques is planned and regulated. PMID:26597866

  19. Anti-VEGF PolysiRNA Polyplex for the Treatment of Choroidal Neovascularization.

    PubMed

    Lee, Jihwang; Ryoo, Na-Kyung; Han, Hyounkoo; Hong, Hye Kyoung; Park, Ji Yeon; Park, Sang Jun; Kim, Yong-Kyu; Sim, Changbeom; Kim, Kwangmeyung; Woo, Se Joon; Park, Kyu Hyung; Kim, Hyuncheol

    2016-06-01

    Choroidal neovascularization (CNV) is a major cause of severe vision loss in patients with age-related macular degeneration (AMD). Present ocular siRNA delivery technology is limited due to poor delivery through the retina to the choroid, where CNV originates. Our goal was to develop an optimized nanosized polyRNAi-based therapeutic delivery system to the subretinal space. We developed it by siRNA multimerization (polysiRNA) followed by coating with branched polyethylenimine and hyaluronic acid, and then evaluated its efficacy in vitro and in vivo. The polysiRNA polyplex showed a narrow size distribution (260.7 ± 43.27 nm) and negative charge (-4.98 ± 0.47 mV) owing to the hyaluronic acid outer layer. In vitro uptake of the polysiRNA polyplex by human ARPE cells was discovered, and the direct inhibition of VEGF mRNA translation was confirmed in B16F10 cells. The intravitreally administered polysiRNA polyplex overcame both the vitreous and retina barriers in vivo and reached the subretinal space efficiently. Intravitreal injection of the polysiRNA polyplex was not toxic to the retina in histopathology. Furthermore, intravitreal injections of the polysiRNA polyplex at both 1 and 7 days after laser photocoagulation inhibited laser-induced choroidal neovascularization, compared to that of the control (p < 0.05). These results suggest that anti-VEGF polysiRNA polyplexes show great potential in delivering multimeric RNAi-based therapeutics to treat retinal or choroidal disorders. PMID:27173745

  20. Comparison of the efficacy of anti-VEGF monotherapy versus PDT and intravitreal anti-VEGF combination treatment in AMD: a Meta-analysis and systematic review

    PubMed Central

    Tong, Yao; Zhao, Ke-Ke; Feng, Dong; Biswal, Manas; Zhao, Pei-Quan; Wang, Zhao-Yang; Zhang, Yun

    2016-01-01

    AIM To compare the effect of anti-vascular endothelial growth factor (VEGF) monotherapy versus photodynamic therapy (PDT) and anti-VEGF combination treatment in age-related macular degeneration (AMD). METHODS A computerized online search was performed using PubMed, Web of Science and the Cochrane Library. Studies that compared anti-VEGF monotherapy with PDT and anti-VEGF combination treatment of AMD and were designed as randomized controlled trials were included. The means and standard deviations of the best-corrected visual acuity (BCVA), central retinal thickness (CRT), number of treatments and proportions of patients who gained BCVA ≥15, 10, 5, or 0 letters at 12th month were extracted. A systematic review and Meta-analysis of the comparison of the two approaches was conducted using Review Manager 5.2. Subgroup. A sensitivity analysis was also performed. RESULTS Eight studies were included. When the subgroup and sensitivity analysis was conducted, the results indicated that in the findings that included the monotherapy group and PDT (standard fluence, SF) group of Kaiser's study, the patients in the monotherapy group had a better BCVA compared with the combination group at 12th month in the PDT (SF) subgroup [weighted mean difference (WMD): 3.54; 95%CI: 0.36 to 6.73; P=0.03], and there were more patients who gained ≥15 letters of BCVA in the monotherapy group compared with the combination group in the total result [odds ratio (OR): 1.41; 95%CI: 1.02 to 1.95; P=0.04]. The same conclusion was obtained in the total result that included the monotherapy group and PDT (reduced fluence, RF) group of Kaiser's study (OR: 1.56; 95%CI: 1.13 to 2.15; P=0.007). However, there were no significant differences in the other indexes between the two therapies. CONCLUSION We found that anti-VEGF monotherapy is more effective on the recovery of visual acuity than combination therapy and more researches with lager sample size should be performed to study on the effect of the two

  1. Comparative Safety and Tolerability of Anti-VEGF therapy in Age-Related Macular Degeneration

    PubMed Central

    Modi, Yasha S.; Tanchon, Carley; Ehlers, Justis P

    2015-01-01

    Neovascular age-related macular degeneration (NVAMD) is one of the leading causes of blindness. Over the last decade, the treatment of NVAMD has been revolutionized by the development intravitreal anti-vascular endothelial growth factor (VEGF) therapies. Several anti-VEGF medications are used for the treatment of NVAMD. The safety and tolerability of these medications deserve review given the high prevalence of NVAMD and the significant utilization of these medications. Numerous large randomized clinical trials have not shown any definitive differential safety relative to ocular or systemic safety of these medications. Intravitreal anti-VEGF therapy does appear to impact systemic VEGF levels, but the implications of these changes remain unclear. One unique safety concern relates drug compounding and the potential risks of contamination, specifically for bevacizumab. Continued surveillance for systemic safety concerns, particularly for rare events is merited. Overall these medications are well tolerated and effective in the treatment of NVAMD. PMID:25700714

  2. Ocular anti-VEGF therapy for diabetic retinopathy: overview of clinical efficacy and evolving applications.

    PubMed

    Cheung, Ning; Wong, Ian Y; Wong, Tien Y

    2014-04-01

    Ocular anti-vascular endothelial growth factor (VEGF) therapy represents one of the most significant advances in modern medicine. The introduction and widespread use of ocular anti-VEGF therapy for age-related macular degeneration heralded a new era in the treatment of vascular and exudative diseases of the retina. Its expanding indications now include diabetic macular edema and proliferative diabetic retinopathy, two vision-threatening forms of diabetic retinopathy. It is widely anticipated that ocular anti-VEGF therapy could spark a dramatic shift in the treatment paradigm for diabetic retinopathy. However, despite its clear efficacy shown in clinical trials, the dynamic landscape of evolving medical, ethical, and economic issues related to this new treatment suggests significant challenges ahead. In this article, we provide a discussion of this topic as part of this two-part Bench to Clinic narrative. Here, our Clinic contribution provides an overview of the current evidence from clinical trials on anti-VEGF therapy for diabetic retinopathy, and highlights the hopes and fears of this new treatment from clinical and public health standpoints. In the Bench narrative that precedes this contribution, Simó et al. provide an overview of the role of VEGF in the pathogenesis of diabetic retinopathy. PMID:24652721

  3. HIF inhibitors for ischemic retinopathies and cancers: options beyond anti-VEGF therapies.

    PubMed

    Subhani, Saima; Vavilala, Divya Teja; Mukherji, Mridul

    2016-07-01

    Aberrant activation of the hypoxia inducible factor (HIF) pathway causing overexpression of angiogenic genes, like vascular endothelial growth factor (VEGF), is one of the underlying causes of ocular neovascularization (NV) and metastatic cancer. Consistently, along with surgical interventions, a number of anti-VEGF agents have been approved by FDA for the treatment of ocular neovascular diseases. These anti-VEGF agents, like ranibizumab/lucentis, have revolutionized the treatment in the past decade. However, substantial vision improvement is observed only in a subset of age-related macular degeneration patients receiving ranibizumab. Further, all current therapies are associated with limitations and side effects. For example, surgeries cause tissue destruction and inflammation while anti-VEGF therapies are expensive, require repeated administration, and offer temporary relief from vascular leakage. These factors impose significant cost and treatment burdens to both the patient and society. With an aging population in most western countries with a continually increasing number of patients on lifelong treatment for these retinal diseases, the focus of ocular drug development for neovascular diseases will be to improve efficacy while reducing treatment costs. Blocking the HIF pathway, a major regulator of ocular NV and cancer, offers an appealing therapeutic strategy. Therefore, this review summarizes HIF inhibitors that have been recently evaluated for the treatment of different cancers and ischemic retinopathies. PMID:27146677

  4. The Role of Anti-VEGF Therapy in the Treatment of Diabetic Macular Edema.

    PubMed

    Moshfeghi, Darius M; Kaiser, Peter K; Michels, Stephan; Midena, Edoardo; Kitchens, John W; Prenner, Jonathan L; Regillo, Carl D; Reichel, Elias

    2016-06-01

    Diabetic retinopathy (DR) is the leading cause of blindness among working-age adults. DR often leads to diabetic macular edema (DME), which often goes unnoticed until a patient presents with vision loss. However, treatment options and data for DME are continually improving. We know that vascular endothelial growth factor (VEGF) plays a key role in DME progression; therapies that act by inhibiting VEGF production seem to improve visual acuity in patients with DME. Of the anti-VEGF therapies available, two have been approved by the U.S. Food and Drug Administration to treat DME: ranibizumab (Lucentis; Genentech, South San Francisco, CA) and aflibercept (Eylea; Regeneron, Tarrytown, NY). Bevacizumab (Avastin; Genentech, South San Francisco, CA), which is approved for the treatment of certain types of cancer, is occasionally used off-label to treat DME. Anti-VEGF therapy can stop vision loss and even improve visual acuity. Other treatments remain effective, and these various treatment options fuel a need for new data and discussion. This roundtable discussion, which took place during the 2015 annual meeting of the American Academy of Ophthalmology, outlines the current protocols used to treat DME and provides clinical opinions about selecting and treating with an appropriate anti-VEGF therapy. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:S5-14.]. PMID:27348433

  5. Bilateral Refractive Changes in Vascularized Pigment Epithelial Detachment Treated by Anti-VEGF Therapy.

    PubMed

    Hanhart, Joel; Chowers, Itay

    2015-01-01

    We report the case of a patient bilaterally treated with anti-VEGF compounds for bilateral massive vascularized retinal pigment epithelial detachment (PED). During the years prior to treatment, PED growth was accompanied by gradual hypermetropization. After right intraocular injection of bevacizumab followed by three bilateral aflibercept injections, the PED flattened resulting in a rapid relative myopization. This case illustrates ocular refractive properties associated with PED and its response to treatment. This case also highlights the importance of assessing refraction in age-related macular degeneration patients experiencing substantial PED amplitude changes. PMID:26955349

  6. Systemic anti-VEGF treatment strongly reduces skin inflammation in a mouse model of psoriasis.

    PubMed

    Schonthaler, Helia B; Huggenberger, Reto; Wculek, Stefanie K; Detmar, Michael; Wagner, Erwin F

    2009-12-15

    Although(,) vascular remodeling is a hallmark of many chronic inflammatory disorders such as rheumatoid arthritis, inflammatory bowel disease, and psoriasis, anti-vascular strategies to treat these conditions have received little attention to date. We investigated the anti-inflammatory activity of systemic blockade of VEGF-A by the inhibitory monoclonal antibody G6-31, employing a therapeutic trial in a mouse model of psoriasis. Simultaneous deletion of JunB and c-Jun (DKO*) in the epidermis of adult mice leads to a psoriasis-like phenotype with hyper- and parakeratosis and increased subepidermal vascularization. Moreover, an inflammatory infiltrate and elevated levels of cytokines/chemokines including TNFalpha, IL-1alpha/beta, IL-6, and the innate immune mediators IL-22, IL-23, IL-23R, and IL-12p40 are detected. Here we show that anti-VEGF antibody treatment of mice already displaying disease symptoms resulted in an overall improvement of the psoriatic lesions leading to a reduction in the number of blood vessels and a significant decrease in the size of dermal blood and lymphatic vessels. Importantly, anti-VEGF-treated mice showed a pronounced reduction of inflammatory cells within the dermis and a normalization of epidermal differentiation. These results demonstrate that systemic blockade of VEGF by an inhibitory antibody might be used to treat patients who have inflammatory skin disorders such as psoriasis. PMID:19995970

  7. A novel small molecule ameliorates ocular neovascularisation and synergises with anti-VEGF therapy.

    PubMed

    Sulaiman, Rania S; Merrigan, Stephanie; Quigley, Judith; Qi, Xiaoping; Lee, Bit; Boulton, Michael E; Kennedy, Breandán; Seo, Seung-Yong; Corson, Timothy W

    2016-01-01

    Ocular neovascularisation underlies blinding eye diseases such as retinopathy of prematurity, proliferative diabetic retinopathy, and wet age-related macular degeneration. These diseases cause irreversible vision loss, and provide a significant health and economic burden. Biologics targeting vascular endothelial growth factor (VEGF) are the major approach for treatment. However, up to 30% of patients are non-responsive to these drugs and they are associated with ocular and systemic side effects. Therefore, there is a need for small molecule ocular angiogenesis inhibitors to complement existing therapies. We examined the safety and therapeutic potential of SH-11037, a synthetic derivative of the antiangiogenic homoisoflavonoid cremastranone, in models of ocular neovascularisation. SH-11037 dose-dependently suppressed angiogenesis in the choroidal sprouting assay ex vivo and inhibited ocular developmental angiogenesis in zebrafish larvae. Additionally, intravitreal SH-11037 (1 μM) significantly reduced choroidal neovascularisation (CNV) lesion volume in the laser-induced CNV mouse model, comparable to an anti-VEGF antibody. Moreover, SH-11037 synergised with anti-VEGF treatments in vitro and in vivo. Up to 100 μM SH-11037 was not associated with signs of ocular toxicity and did not interfere with retinal function or pre-existing retinal vasculature. SH-11037 is thus a safe and effective treatment for murine ocular neovascularisation, worthy of further mechanistic and pharmacokinetic evaluation. PMID:27148944

  8. Switch of anti-VEGF agents is an option for nonresponders in the treatment of AMD

    PubMed Central

    Ehlken, C; Jungmann, S; Böhringer, D; Agostini, H T; Junker, B; Pielen, A

    2014-01-01

    Background Although anti-VEGF therapy of exudative AMD with bevacizumab and ranibizumab proved efficacious in the majority of patients, CNV activity does not respond to continued treatment after repeated injections in a considerable amount of patients. These are referred to as nonresponders. A change of the drug to bevacizumab or ranibizumab could possibly offer an alternative option for the treatment of nonresponding exudative AMD. Methods and materials A total of 138 nonresponders who switched therapy from bevacizumab to ranibizumab (n=114) or vice versa (n=24) were included in a retrospective study. Visual acuity (VA) and foveal thickness before and after the switch of therapy were compared. By means of linear regression analysis, we analyzed possible prognostic factors associated with a favorable outcome for visual acuity. Results Linear regression analysis revealed a statistically significant benefit for nonresponders when treatment was changed to a different anti-VEGF drug (bevacizumab or ranibizumab). VA at the time of the switch was positively correlated with a beneficial development of VA after changing the drug. There was no significant correlation with age, macular thickness, number of injections before the switch, or the development of VA under treatment before the switch. Both patients switching to Avastin and Lucentis benefitted without statistically significant differences. Conclusions An exchange of bevacizumab with ranibizumab or vice versa should be considered in nonresponders in the treatment of exudative AMD. Further prognostic factors may help to identify patients who might benefit from a switch. These factors should be investigated in further studies. PMID:24722504

  9. Anti-vascular therapies in ovarian cancer: moving beyond anti-VEGF approaches

    PubMed Central

    Choi, Hyun-Jin; Pena, Guillermo N. Armaiz; Pradeep, Sunila; Cho, Min Soon; Coleman, Robert L.; Sood, Anil K.

    2014-01-01

    Resistance to chemotherapy is among the most important issues in the management of ovarian cancer. Unlike cancer cells, which are heterogeneous as a result of remarkable genetic instability, stromal cells are considered relatively homogeneous. Thus, targeting the tumor microenvironment is an attractive approach for cancer therapy. Arguably, anti-vascular endothelial growth factor (anti-VEGF) therapies hold great promise, but their efficacy has been modest, likely owing to redundant and complementary angiogenic pathways. Components of platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), epidermal growth factor (EGF), and other pathways may compensate for VEGF blockade and allow angiogenesis to occur despite anti-VEGF treatment. In addition, hypoxia induced by antiangiogenesis therapy modifies signaling pathways in tumor and stromal cells, which induces resistance to therapy. Because of tumor cell heterogeneity and angiogenic pathway redundancy, combining cytotoxic and targeted therapies or combining therapies targeting different pathways can potentially overcome resistance. Although targeted therapy is showing promise, much more work is needed to maximize its impact, including the discovery of new targets and identification of individuals most likely to benefit from such therapies. PMID:25544368

  10. Coaxial Electrospray of Ranibizumab-Loaded Microparticles for Sustained Release of Anti-VEGF Therapies

    PubMed Central

    Fischer, Andrew J.; Letson, Alan; Yuan, Shuai; Roberts, Cynthia J.; Xu, Ronald X.

    2015-01-01

    Age-related macular degeneration (AMD) is the leading cause of vision loss and blindness in people over age 65 in industrialized nations. Intravitreous injection of anti-VEGF (vascular endothelial growth factor) therapies, such as ranibizumab (trade name: Lucentis), provides an effective treatment option for neovascular AMD. We have developed an improved coaxial electrospray (CES) process to encapsulate ranibizumab in poly(lactic-co-glycolic) acid (PLGA) microparticles (MPs) for intravitreous injection and sustained drug release. This microencapsulation process is advantageous for maintaining the stability of the coaxial cone-jet configurations and producing drug-loaded MPs with as high as 70% encapsulation rate and minimal loss of bioactivitiy. The utility of this emerging process in intravitreous drug delivery has been demonstrated in both benchtop and in vivo experiments. The benchtop test simulates ocular drug release using PLGA MPs encapsulating a model drug. The in vivo experiment evaluates the inflammation and retinal cell death after intravitreal injection of the MPs in a chick model. The experimental results show that the drug-load MPs are able to facilitate sustained drug release for longer than one month. No significant long term microglia reaction or cell death is observed after intravitreal injection of 200 μg MPs. The present study demonstrates the technical feasibility of using the improved CES process to encapsulate water-soluble drugs at a high concentration for sustained release of anti-VEGF therapy. PMID:26273831

  11. A novel small molecule ameliorates ocular neovascularisation and synergises with anti-VEGF therapy

    PubMed Central

    Sulaiman, Rania S.; Merrigan, Stephanie; Quigley, Judith; Qi, Xiaoping; Lee, Bit; Boulton, Michael E.; Kennedy, Breandán; Seo, Seung-Yong; Corson, Timothy W.

    2016-01-01

    Ocular neovascularisation underlies blinding eye diseases such as retinopathy of prematurity, proliferative diabetic retinopathy, and wet age-related macular degeneration. These diseases cause irreversible vision loss, and provide a significant health and economic burden. Biologics targeting vascular endothelial growth factor (VEGF) are the major approach for treatment. However, up to 30% of patients are non-responsive to these drugs and they are associated with ocular and systemic side effects. Therefore, there is a need for small molecule ocular angiogenesis inhibitors to complement existing therapies. We examined the safety and therapeutic potential of SH-11037, a synthetic derivative of the antiangiogenic homoisoflavonoid cremastranone, in models of ocular neovascularisation. SH-11037 dose-dependently suppressed angiogenesis in the choroidal sprouting assay ex vivo and inhibited ocular developmental angiogenesis in zebrafish larvae. Additionally, intravitreal SH-11037 (1 μM) significantly reduced choroidal neovascularisation (CNV) lesion volume in the laser-induced CNV mouse model, comparable to an anti-VEGF antibody. Moreover, SH-11037 synergised with anti-VEGF treatments in vitro and in vivo. Up to 100 μM SH-11037 was not associated with signs of ocular toxicity and did not interfere with retinal function or pre-existing retinal vasculature. SH-11037 is thus a safe and effective treatment for murine ocular neovascularisation, worthy of further mechanistic and pharmacokinetic evaluation. PMID:27148944

  12. Effects of Anti-VEGF on Predicted Antibody Biodistribution: Roles of Vascular Volume, Interstitial Volume, and Blood Flow

    PubMed Central

    Boswell, C. Andrew; Ferl, Gregory Z.; Mundo, Eduardo E.; Bumbaca, Daniela; Schweiger, Michelle G.; Theil, Frank-Peter; Fielder, Paul J.; Khawli, Leslie A.

    2011-01-01

    Background The identification of clinically meaningful and predictive models of disposition kinetics for cancer therapeutics is an ongoing pursuit in drug development. In particular, the growing interest in preclinical evaluation of anti-angiogenic agents alone or in combination with other drugs requires a complete understanding of the associated physiological consequences. Methodology/Principal Findings Technescan™ PYP™, a clinically utilized radiopharmaceutical, was used to measure tissue vascular volumes in beige nude mice that were naïve or administered a single intravenous bolus dose of a murine anti-vascular endothelial growth factor (anti-VEGF) antibody (10 mg/kg) 24 h prior to assay. Anti-VEGF had no significant effect (p>0.05) on the fractional vascular volumes of any tissues studied; these findings were further supported by single photon emission computed tomographic imaging. In addition, apart from a borderline significant increase (p = 0.048) in mean hepatic blood flow, no significant anti-VEGF-induced differences were observed (p>0.05) in two additional physiological parameters, interstitial fluid volume and the organ blood flow rate, measured using indium-111-pentetate and rubidium-86 chloride, respectively. Areas under the concentration-time curves generated by a physiologically-based pharmacokinetic model changed substantially (>25%) in several tissues when model parameters describing compartmental volumes and blood flow rates were switched from literature to our experimentally derived values. However, negligible changes in predicted tissue exposure were observed when comparing simulations based on parameters measured in naïve versus anti-VEGF-administered mice. Conclusions/Significance These observations may foster an enhanced understanding of anti-VEGF effects in murine tissues and, in particular, may be useful in modeling antibody uptake alone or in combination with anti-VEGF. PMID:21436893

  13. Seroprevalence of Encephalitozoon cuniculi in Humans and Rabbits in China

    PubMed Central

    PAN, Yaoqian; WANG, Shuai; LIU, Xingyou; LI, Ruizhen; SUN, Yuqian; GADAHI, Javaid Ali

    2015-01-01

    Background: Encephalitozoon cuniculi is a microsporidian parasite commonly found in rabbits that can infect humans, causing encephalitozoonosis. Our objective in this study was to evaluate the seroprevalence of this parasite in rabbits and humans in China Methods: Overall, 300 serum samples each from clinically healthy rabbit and human were collected from three regions of China (Sichuan Province, Chongqing Municipality and Jilin Province) from January to September 2013 and tested for anti-E. Cuniculi antibodies using an ELISA. Results: An overall seroprevalence of E. cuniculi was recorded as 56/300 (18.76%) and 29/300 (9.76%) in rabbit and human sera, respectively. The seropositivity of rabbit samples collected from Jilin province was 41%, which was significantly higher (P<0.01) than Sichuan Province (9%) and Chongqing Municipality (6%). Three breeds of rabbit were used in the present study and antibody detection in Rex Rabbit was significantly (P<0.01) higher than Japanese White and New Zealand Rabbit. In human, Jilin province was more prevalent (18%) followed by Sichuan Province (6%) and Chongqing Municipality (5%). Conclusions: The E. cuniculi was present and widespread among healthy rabbits and humans in China PMID:26246829

  14. Response to anti-VEGF-A treatment of endothelial cells in vitro.

    PubMed

    Puddu, Alessandra; Sanguineti, Roberta; Traverso, Carlo Enrico; Viviani, Giorgio L; Nicolò, Massimo

    2016-05-01

    This study was conducted to compare the effects of two anti-VEGF-A drugs, Ranibizumab and Aflibercept, on the expression and secretion of VEGFs family members, and on their influence in proliferation and migration of endothelial cells (HECV) in vitro. HECV cells were exposed 24 h (T1), 4 days (T2) and 6 days (T3) to Ranibizumab or Aflibercept at pharmacodynamically relevant concentrations (Ranibizumab: 12.5 μg/ml and 125 μg/ml; Aflibercept: 50 μg/ml and 500 μg/ml). Cell viability and then expression and secretion of VEGF-A, VEGF-B, VEGF-C and PlGF were evaluated respectively by Real Time-PCR and ELISA. Intracellular signaling activated by VEGF-A and VEGF-C was investigated evaluating phosphorylation of VEGFR2. Influence in would healing was evaluated through scratch assay. In general no differences were observed among the tested concentrations of anti-vegf drugs. Ranibizumab and Aflibercept did not affect HECV cell viability in all experimental times. At T1, Ranibizumab decreased mRNA levels of VEGF-A, induced VEGF-C secretion, abrogated phosphorylation of VEGFR2 stimulated by VEGF-A, and impaired ability of HECV cells to repair wound healing. Aflibercept decreased mRNA levels of VEGF-A, -B and PlGF; slightly increased basal level of phVEGFR2, and completely abrogated phosphorylation stimulated by VEGF-A and VEGF-C. No effects on secretion of VEGF-B and on would healing were observed after exposure to Aflibercept. Prolonged exposure to anti-VEGFs decreased expression and secretion of VEGF-A and VEGF-B, up-regulated VEGF-C mRNA levels and its secretion, and increased basal phosphorylation of VEGFR2. Acute treatment with Ranibizumab or Aflibercept evoked different responses on endothelial cells, however these differences were lost after prolonged exposure. Scratch test results suggest that treatment with Ranibizumab may be more effective than Aflibercept in reducing angiogenic potential of endothelial cells in vitro. PMID:26771090

  15. Therapeutic effect of dexamethasone implant in retinal vein occlusions resistant to anti-VEGF therapy

    PubMed Central

    Wallsh, Josh; Sharareh, Behnam; Gallemore, Ron

    2016-01-01

    Purpose To test the efficacy of the intravitreal dexamethasone (DEX) implant in patients with retinal vein occlusions (RVOs) who have failed multiple anti-vascular endothelial growth factor (anti-VEGF) treatments. Methods A randomized exploratory study of ten patients with branch RVO or central RVO who received at least two previous anti-VEGF treatments and had persistent or unresponsive cystoid macular edema. Treatment with the DEX implant was either every 4 months or pro re nata (PRN) depending on their group assignment for 1 year. Multifocal electroretinography and microperimetry were the primary end points, with high-resolution optical coherence tomography and best-corrected visual acuity as the secondary end points. Results All patients in both the every 4 month and PRN cohorts who completed the study received the three maximal injections of DEX; therefore, the data from both cohorts were combined and reported as a case series. On average, the multifocal electroretinography amplitude increased significantly from 5.11±0.66 to 24.19±5.30 nV/deg2 at 12 months (P<0.005), mean macular sensitivity increased from 7.67±2.10 to 8.01±1.98 dB at 4 months (P=0.32), best-corrected visual acuity increased significantly from 51.0±5.1 to 55.4±5.1 early treatment of diabetic retinopathy study letters at 2 months (P<0.05), and central retinal thickness decreased from 427.6±39.5 to 367.1±37.8 μm at 4 months (P<0.05). Intraocular pressure increased significantly in one patient, with that patient requiring an additional glaucoma medication for management. Additionally, cataract progression increased significantly (P<0.05) in this patient population and partially limited analysis of other end points. Conclusion DEX should be considered as a treatment option in patients with RVOs who have failed anti-VEGF therapy, as the results of this study demonstrated an improvement in retinal morphology and macular function. Cataract progression did occur following multiple consecutive

  16. Transgenic rabbit that expresses a functional human lipoprotein (a)

    DOEpatents

    Rouy, Didier; Duverger, Nicolas; Emmanuel, Florence; Denefle, Patrice; Houdebine, Louis-Marie; Viglietta, Celine; Rubin, Edward M.; Hughes, Steven D.

    2003-01-01

    A transgenic rabbit which has in its genomic DNA sequences that encode apolipoprotein (a) and apolipoprotein B polypeptides which are capable of combining to produce lipoprotein (a), a process for creating such a rabbit, and the use of the rabbit to identify compounds which are effective in the treatment of human diseases which are associated with, induced and/or exacerbated by Lp(a) expression.

  17. The Structural Basis for the Function of Two Anti-VEGF Receptor 2 Antibodies

    SciTech Connect

    M Franklin; E Navarro; Y Wang; S Patel; P Singh; Y Zhang; K Persaud; A Bari; H Griffith; et al.

    2011-12-31

    The anti-VEGF receptor 2 antibody IMC-1121B is a promising antiangiogenic drug being tested for treatment of breast and gastric cancer. We have determined the structure of the 1121B Fab fragment in complex with domain 3 of VEGFR2, as well as the structure of a different neutralizing anti-VEGFR2 antibody, 6.64, also in complex with VEGFR2 domain 3. The two Fab fragments bind at opposite ends of VEGFR2 domain 3; 1121B directly blocks VEGF binding, whereas 6.64 may prevent receptor dimerization by perturbing the domain 3:domain 4 interface. Mutagenesis reveals that residues essential for VEGF, 1121B, and 6.64 binding are nonoverlapping among the three contact patches.

  18. The Structural Basis for the Function of Two Anti-VEGF Receptor 2 Antibodies

    SciTech Connect

    Franklin, Matthew C.; Navarro, Elizabeth C.; Wang, Yujie; Patel, Sheetal; Singh, Pinki; Zhang, Yi; Persaud, Kris; Bari, Amtul; Griffith, Heather; Shen, Leyi; Balderes, Paul; Kussie, Paul

    2011-10-28

    The anti-VEGF receptor 2 antibody IMC-1121B is a promising antiangiogenic drug being tested for treatment of breast and gastric cancer. We have determined the structure of the 1121B Fab fragment in complex with domain 3 of VEGFR2, as well as the structure of a different neutralizing anti-VEGFR2 antibody, 6.64, also in complex with VEGFR2 domain 3. The two Fab fragments bind at opposite ends of VEGFR2 domain 3; 1121B directly blocks VEGF binding, whereas 6.64 may prevent receptor dimerization by perturbing the domain 3:domain 4 interface. Mutagenesis reveals that residues essential for VEGF, 1121B, and 6.64 binding are nonoverlapping among the three contact patches.

  19. Bevacizumab (Avastin) conjugated microbubbles for anti-VEGF treatment of neovascular age-related macular degeneration

    NASA Astrophysics Data System (ADS)

    Zhang, Leilei; Xu, Jeff; Huang, Jiwei; Roberts, Cynthia; Xu, Ronald

    2010-02-01

    Bevacizumab (Avastin) has been used as one of the anti-VEGF therapies to manage neovascular age-related macular degeneration (AMD). The drug delivery system for bevacizumab needs to be improved in order to decrease the frequency of injection and reduce the adverse effects. In our study, bevacizumab was conjugated with poly (lactic-co-glycolic acid) (PLGA) microbubbles by activating carboxyl functional groups. The averaged size of microbubbles was estimated 1.055+/-0.258μm, allowing for ultrasound guided drug delivery. The binding efficiency between bevacizumab and microbubbles was evaluated in an enzyme-linked immunosorbent assay plate. The test results demonstrated the potential of using PLGA microbubbles to deliver bevacizumab with imaging guidance.

  20. Experiences of patients undergoing anti-VEGF treatment for neovascular age-related macular degeneration: a systematic review.

    PubMed

    Boyle, Jessica; Vukicevic, Meri; Koklanis, Konstandina; Itsiopoulos, Catherine

    2015-01-01

    Current therapy to slow disease progression in patients with neovascular age-related macular degeneration (AMD) often entails intra-vitreal injection of an anti-vascular endothelial growth factor (VEGF) agent, that begins with a three-month loading phase of four weekly injections followed by regular monthly visits with clinician-determined re-treatment. The effects of AMD on quality of life and visual function have been extensively reported in the literature, however, less is known about the burden imposed on patients by the arduous and often indefinite treatment schedule which habitually follows a diagnosis of wet AMD. To date, no systematic review has been conducted of research investigating patients' experiences of anti-VEGF treatment for AMD. A systematic search of the Embase, Medline, PsycINFO and PubMed electronic databases was undertaken to identify all studies between January 2004 and December 2013, published in the English language and involving human participants. A hand-search of an additional four journals was conducted. Ten articles were identified for inclusion in this review. A critical appraisal was undertaken using the Critical Appraisal Skills Programme Qualitative Research Checklist and the results synthesised to form a narrative review. Few studies to date have investigated patients' experiences of treatment for AMD. These studies have focused primarily on patients' experiences of the injection procedure with respect to pain and anxiety. Anticipated discomfort is often greater than actual discomfort experienced during intra-vitreal injection. However, different stages of the treatment procedure produce varying levels of patient discomfort. No one method of anaesthesia has consistently been shown to be more effective in reducing discomfort associated with treatment. Common reasons underlying patient apprehension surrounding treatment include the thought of having an injection, fear of losing eyesight and fear of the unknown. Whilst these studies

  1. Experimental studies of a vaccine formulation of recombinant human VEGF antigen with aluminum phosphate

    PubMed Central

    Pérez Sánchez, Lincidio; Morera Díaz, Yanelys; Bequet-Romero, Mónica; Ramses Hernández, Gerardo; Rodríguez, Yadira; Castro Velazco, Jorge; Puente Pérez, Pedro; Ayala Avila, Marta; Gavilondo, Jorge V

    2015-01-01

    CIGB-247 is a cancer vaccine that is a formulation of a recombinant protein antigen representative of the human vascular endothelial growth factor (VEGF) with a bacterially-derived adjuvant (VSSP). The vaccine has shown an excellent safety profile in mice, rats, rabbits, not-human primates and in recent clinical trials in cancer patients. Response to the vaccine is characterized by specific antibody titers that neutralize VEGF/VEGFR2 binding and a cytotoxic tumor-specific response. To expand our present anti-VEGF active immunotherapy strategies, we have now studied in mice and non-human primates the effects of vaccination with a formulation of our recombinant VEGF antigen and aluminum phosphate adjuvant (hereafter denominated CIGB-247-A). Administered bi-weekly, CIGB-247-A produces high titers of anti-VEGF IgG blocking antibodies in 2 mice strains. Particularly in BALB/c, the treatment impaired subcutaneous F3II mammary tumor growth and reduced the number of spontaneous lung macro metastases, increasing animals' survival. Spleen cells from specifically immunized mice directly killed F3II tumor cells in vitro. CIGB-247-A also showed to be immunogenic in non-human primates, which developed anti-VEGF blocking antibodies and the ability for specific direct cell cytotoxic responses, all without impairing the healing of deep skin wounds or other side effect. Our results support consideration of aluminum phosphate as a suitable adjuvant for the development of new vaccine formulations using VEGF as antigen. PMID:25891359

  2. [The revolution in the treatment of retinal diseases: anti-VEGF treatment at the Assuta Eye Institute].

    PubMed

    Katz, Gabriel; Zehavi, Chaya; Treister, Giora

    2015-04-01

    The VEGF protein (Vascular Endothelial Growth Factor) was identified in the '80s as a factor which induces proliferation of blood vessels in the body in general and in the retina in particular. Proliferative processes in retinal blood vessels, vascular permeability and induced edema which follows, frequently cause blindness in the diseases of the macula: AMD (Age-related Macular Degeneration) diabetes and retinal vascular occlusions. Since 2006, through treatment using anti-VEGF drugs--Avastin (Bevacizumab) and Lucentis (Ranibizumab) and Eylea (Aflibercept)--blindness in many patients in Israel and elsewhere was prevented. This paper reviews the treatment with anti-VEGF intraocular injections in the above mentioned diseases with reference to the growing activity at the Assuta Eye Institute. PMID:26065226

  3. Vascular effects induced by anti-VEGF agents in the CAM model: effect of the DMSO

    NASA Astrophysics Data System (ADS)

    Nowak-Sliwinska, Patrycja; Ballini, Jean-Pierre; van den Bergh, Hubert; Wagnières, Georges

    2009-06-01

    The chicken embryo's chorioallantoic membrane (CAM) is widely used as an in vivo model to study the vascular effects induced by agents administrated topically or intravenously. Hence, in the vascular plexus of this respiratory membrane, angiogenic and anti-angiogenic agents, as well as phototoxic effects have been studied. The main goal of this study was to characterize the capillary network of the CAM after topical administration of dimethyl sulfoxid (DMSO), a frequently used solvent of lipophylic drugs, including potent anti-VEGF agents. The CAM capillaries were observed between days 8 and 9 of the embryo development, with an epi-fluorescence microscope equipped with a sensitive camera by intravenous injection of a fluorescent agent and a non-fluorescing absorber (in the extra-embryonic cavity) to screen the tissue background fluorescence. The fluorescence images of the CAM vasculature were then processed in order to obtain a skeleton of the vessels and capillaries. This was done to quantify descriptors such as the number of branching points/mm2, the mean area value of the vessels network meshes, and the mean of the 3rd quartile of the histogram of these meshes, were then extracted. Our results demonstrate that the topical administration of an aqueous solution of 20 μl of DMSO at concentrations equal or larger than 0.1% turned out to modify the capillary network morphology in a dose-dependent manner as compared to the control (20 μl of 0.9% NaCl).

  4. Variants in the APOE Gene Are Associated with Improved Outcome after Anti-VEGF Treatment for Neovascular AMD

    PubMed Central

    Xie, Jing; Lim, Jonathan; Chauhan, Devinder S.; Robman, Luba; Richardson, Andrea J.; Hageman, Gregory; Baird, Paul N.; Guymer, Robyn

    2011-01-01

    Purpose. Anti-vascular endothelial growth factor (anti-VEGF) drugs have dramatically improved the treatment of neovascular AMD. In pivotal studies, almost 90% of patients maintain vision, with approximately 30% showing significant improvement. Despite these successes, 10% to 15% of patients continue to lose vision, even with treatment. It has been reported that variants in some AMD-associated genes influence treatment outcome. This study showed an association of treatment outcome with variants in the apolipoprotein E (APOE) gene. Methods. One hundred ninety-two patients receiving anti-VEGF treatment for subfoveal choroidal neovascularization secondary to AMD were enrolled. Information on demographics, lesion characteristics, delay until treatment, visual acuity (VA), and number of treatments was collected, and variants of APOE were assessed in all patients at baseline. Best corrected logarithm of the minimum angle of resolution (logMAR) VA was recorded in all patients. Results. The presence of the APOE ε4 allele was associated with improved treatment outcome at 3 (P = 0.02) and 12 (P = 0.06) months, compared with the presence of the ε2 allele, after adjustment for baseline acuity, treatment delay after first symptoms, age, and sex. Patients with an APOE ε4 allele had an odds ratio (OR) of 4.04 (95% confidence interval [CI], 1.11–14.70) for a 2-line gain in vision from baseline at 3 months (P = 0.03) and an OR of 2.54 (95% CI, 0.61–10.52; P = 0.20) at 12 months after treatment, based on multivariate analysis. Conclusions. In patients with neovascular AMD, the presence of the APOE ε4 allele conferred significantly better visual outcomes after anti-VEGF treatment than did the ε2 allele. These findings suggest a possible role for a personalized approach to treatment with anti-VEGF. PMID:21245410

  5. Treatment of neovascular age-related macular degeneration with anti-VEGF agents: retrospective analysis of 5-year outcomes

    PubMed Central

    Pedrosa, Ana Catarina; Reis-Silva, Adriana; Pinheiro-Costa, João; Beato, João; Freitas-da-Costa, Paulo; Falcão, Manuel S; Falcão-Reis, Fernando; Carneiro, Ângela

    2016-01-01

    Purpose To evaluate the 5-year results obtained in clinical practice in the treatment of neovascular age-related macular degeneration (nAMD) with anti-VEGF agents. Materials and methods We retrospectively analyzed all patients with nAMD who initiated anti-VEGF treatment before October 2009. We collected data regarding visual and anatomical outcomes. Results A total of 278 patients met the selection criteria. The mean number of intravitreal injections was 5.7 in the first year and 3.7 in the fifth year. A positive mean visual acuity variation of +3.7 Early Treatment Diabetic Retinopathy Study letters occurred in the first year, but no significant differences relative to baseline were observed thereafter. The majority of patients (71%) maintained stable visual acuity throughout follow-up. At 5 years, mean central macular thickness remained substantially inferior to baseline (−96.6 μm), and 56% of patients maintained dry retinas. Conclusion Anti-VEGF therapy leads to long-term visual stabilization in the great majority of patients. PMID:27099460

  6. Resistance to Anti-VEGF Therapy Mediated by Autocrine IL6/STAT3 Signaling and Overcome by IL6 Blockade.

    PubMed

    Eichten, Alexandra; Su, Jia; Adler, Alexander P; Zhang, Li; Ioffe, Ella; Parveen, Asma A; Yancopoulos, George D; Rudge, John; Lowy, Israel; Lin, Hsin Chieh; MacDonald, Douglas; Daly, Christopher; Duan, Xunbao; Thurston, Gavin

    2016-04-15

    Anti-VEGF therapies benefit several cancer types, but drug resistance that limits therapeutic response can emerge. We generated cell lines from anti-VEGF-resistant tumor xenografts to investigate the mechanisms by which resistance develops. Of all tumor cells tested, only A431 (A431-V) epidermoid carcinoma cells developed partial resistance to the VEGF inhibitor aflibercept. Compared with the parental tumors, A431-V tumors secreted greater amounts of IL6 and exhibited higher levels of phospho-STAT3. Notably, combined blockade of IL6 receptor (IL6R) and VEGF resulted in enhanced activity against A431-V tumors. Similarly, inhibition of IL6R enhanced the antitumor effects of aflibercept in DU145 prostate tumor cells that displays high endogenous IL6R activity. In addition, post hoc stratification of data obtained from a clinical trial investigating aflibercept efficacy in ovarian cancer showed poorer survival in patients with high levels of circulating IL6. These results suggest that the activation of the IL6/STAT3 pathway in tumor cells may provide a survival advantage during anti-VEGF treatment, suggesting its utility as a source of response biomarkers and as a therapeutic target to heighten efficacious results. Cancer Res; 76(8); 2327-39. ©2016 AACR. PMID:26921327

  7. Global reported endophthalmitis risk following intravitreal injections of anti-VEGF: a literature review and analysis

    PubMed Central

    Sigford, Douglas K; Reddy, Shivani; Mollineaux, Christine; Schaal, Shlomit

    2015-01-01

    Purpose To report on endophthalmitis occurrence and associated risk factors following the intravitreal injection of anti-VEGF agents based on a review of published literature. Materials and methods A Medline search was performed using the terms “bevacizumab” and “ranibizumab”. A total of 534 English-language articles of varying design and published from 2006 to November 2013 were analyzed for endophthalmitis occurrence and contributing perioperative factors. Results A total of 445,503 injections were counted. There were 103 cases of postinjection endophthalmitis in 176,124 injections (0.058%) with bevacizumab (Avastin) versus 79 cases in 269,379 injections (0.029%) with ranibizumab (Lucentis). This difference was due to a significantly higher occurrence of culture-negative endophthalmitis associated with bevacizumab injections. Culture-positive risk was not statistically different between the two drugs. The reported use of postinjection topical antibiotics increased the risk of culture-positive endophthalmitis. No association was found with the use of povidone iodine, a lid speculum, a mask, or an operating room. Streptococcus spp. were the most prevalent causative organism, accounting for nine of 54 (17%) of all culture-positive cases. Conclusion Reported postinjection endophthalmitis occurred significantly more in patients treated with bevacizumab than those treated with ranibizumab. However, culture-positive occurrence was similar. Despite the potential for contamination at the time of drug compounding, bevacizumab does not appear to confer a higher risk of culture-positive endophthalmitis than ranibizumab. This study also suggests antibiotic use may increase endophthalmitis occurrence. PMID:25999685

  8. Improved tumor vascularization after anti-VEGF therapy with carboplatin and nab-paclitaxel associates with survival in lung cancer

    PubMed Central

    Heist, Rebecca S.; Duda, Dan G.; Sahani, Dushyant V.; Ancukiewicz, Marek; Fidias, Panos; Sequist, Lecia V.; Temel, Jennifer S.; Shaw, Alice T.; Pennell, Nathan A.; Neal, Joel W.; Gandhi, Leena; Lynch, Thomas J.; Engelman, Jeffrey A.; Jain, Rakesh K.

    2015-01-01

    Addition of anti-VEGF antibody therapy to standard chemotherapies has improved survival and is an accepted standard of care for advanced non–small cell lung cancer (NSCLC). However, the mechanisms by which anti-VEGF therapy increases survival remain unclear. We evaluated dynamic CT-based vascular parameters and plasma cytokines after bevacizumab alone and after bevacizumab plus chemotherapy with carboplatin and nab-paclitaxel in advanced NSCLC patients to explore potential biomarkers of treatment response and resistance to this regimen. Thirty-six patients were enrolled in this study. The primary end point was 6-mo progression-free survival rate, which was 74% (95% CI: 57, 97). This regimen has a promising overall response rate of 36% and median time to progression of 8.5 (6.0, 38.7) mo and overall survival of 12.2 (9.6, 44.1) mo. We found that anti-VEGF therapy led to a sustained increase in plasma PlGF, a potential pharmacodynamic marker. We also found that higher levels of soluble VEGFR1 measured before starting bevacizumab with chemotherapy were associated with worse survival, supporting its potential role as biomarker of treatment resistance. Our imaging biomarker studies indicate that bevacizumab-based treatment—while reducing blood flow, volume, and permeability in the overall population—may be associated with improved survival in patients with improved tumor vasculature and blood perfusion after treatment. This hypothesis-generating study supports the notion that excessively decreasing vascular permeability and pruning/rarefaction after bevacizumab therapy may negatively impact the outcome of combination therapy in NSCLC patients. This hypothesis warrants further dose-titration studies of bevacizumab to examine the dose effect on tumor vasculature and treatment efficacy. PMID:25605928

  9. Optimizing the Anti-VEGF Treatment Strategy for Neovascular Age-Related Macular Degeneration: From Clinical Trials to Real-Life Requirements

    PubMed Central

    Mantel, Irmela

    2015-01-01

    This Perspective discusses the pertinence of variable dosing regimens with anti-vascular endothelial growth factor (VEGF) for neovascular age-related macular degeneration (nAMD) with regard to real-life requirements. After the initial pivotal trials of anti-VEGF therapy, the variable dosing regimens pro re nata (PRN), Treat-and-Extend, and Observe-and-Plan, a recently introduced regimen, aimed to optimize the anti-VEGF treatment strategy for nAMD. The PRN regimen showed good visual results but requires monthly monitoring visits and can therefore be difficult to implement. Moreover, application of the PRN regimen revealed inferior results in real-life circumstances due to problems with resource allocation. The Treat-and-Extend regimen uses an interval based approach and has become widely accepted for its ease of preplanning and the reduced number of office visits required. The parallel development of the Observe-and-Plan regimen demonstrated that the future need for retreatment (interval) could be reliably predicted. Studies investigating the observe-and-plan regimen also showed that this could be used in individualized fixed treatment plans, allowing for dramatically reduced clinical burden and good outcomes, thus meeting the real life requirements. This progressive development of variable dosing regimens is a response to the real-life circumstances of limited human, technical, and financial resources. This includes an individualized treatment approach, optimization of the number of retreatments, a minimal number of monitoring visits, and ease of planning ahead. The Observe-and-Plan regimen achieves this goal with good functional results. Translational Relevance: This perspective reviews the process from the pivotal clinical trials to the development of treatment regimens which are adjusted to real life requirements. The article discusses this translational process which– although not the classical interpretation of translation from fundamental to clinical

  10. The quantitation of C6 in rabbit and human sera

    PubMed Central

    Tedesco, F.; Lachmann, P. J.

    1971-01-01

    C6 quantitation was carried out in rabbit and human sera by the single radial immunodiffusion technique. The C6 content of the rabbit and human sera used as standards was estimated by precipitin analysis, using an anti-C6 antiserum labelled with 125I. The mean C6 level in normal human serum was 11 μg/ml, whereas in normal rabbit serum it was 35 μg/ml. Sera from forty rabbits heterozygous for C6 deficiency were found to have a mean concentration of C6 of 14 μg/ml. The C6 level was estimated in sera from patients with various immunological disorders and found to be significantly higher in the sera from patients with rheumatoid arthritis and normal in the sera from patients with SLE, glomerulonephritis, nephrotic syndrome and myeloma. C6 haemolytic assays were found to correlate well with the antigenic assays only in fresh sera. In various circumstances this correlation breaks down, presumably because of C6 inactivator. This inactivator, in contrast to C3-inactivator, appears to be bound to antigen–antibody complement complexes. ImagesFig. 2Fig. 3 PMID:4998970

  11. Oncogenic RAS pathway activation promotes resistance to anti-VEGF therapy through G-CSF-induced neutrophil recruitment.

    PubMed

    Phan, Vernon T; Wu, Xiumin; Cheng, Jason H; Sheng, Rebecca X; Chung, Alicia S; Zhuang, Guanglei; Tran, Christopher; Song, Qinghua; Kowanetz, Marcin; Sambrone, Amy; Tan, Martha; Meng, Y Gloria; Jackson, Erica L; Peale, Franklin V; Junttila, Melissa R; Ferrara, Napoleone

    2013-04-01

    Granulocyte-colony stimulating factor (G-CSF) promotes mobilization of CD11b(+)Gr1(+) myeloid cells and has been implicated in resistance to anti-VEGF therapy in mouse models. High G-CSF production has been associated with a poor prognosis in cancer patients. Here we show that activation of the RAS/MEK/ERK pathway regulates G-CSF expression through the Ets transcription factor. Several growth factors induced G-CSF expression by a MEK-dependent mechanism. Inhibition of G-CSF release with a MEK inhibitor markedly reduced G-CSF production in vitro and synergized with anti-VEGF antibodies to reduce CD11b(+)Ly6G(+) neutrophil mobilization and tumor growth and led to increased survival in animal models of cancer, including a genetically engineered mouse model of pancreatic adenocarcinoma. Analysis of biopsies from pancreatic cancer patients revealed increased phospho-MEK, G-CSF, and Ets expression and enhanced neutrophil recruitment compared with normal pancreata. These results provide insights into G-CSF regulation and on the mechanism of action of MEK inhibitors and point to unique anticancer strategies. PMID:23530240

  12. Epidemiological and Clinical Baseline Characteristics as Predictive Biomarkers of Response to Anti-VEGF Treatment in Patients with Neovascular AMD.

    PubMed

    Tsilimbaris, Miltiadis K; López-Gálvez, Maria I; Gallego-Pinazo, Roberto; Margaron, Philippe; Lambrou, George N

    2016-01-01

    Purpose. To review the current literature investigating patient response to antivascular endothelial growth factor-A (VEGF) therapy in the treatment of neovascular age-related macular degeneration (nAMD) and to identify baseline characteristics that might predict response. Method. A literature search of the PubMed database was performed, using the keywords: AMD, anti-VEGF, biomarker, optical coherence tomography, treatment outcome, and predictor. The search was limited to articles published from 2006 to date. Exclusion criteria included phase 1 trials, case reports, studies focusing on indications other than nAMD, and oncology. Results. A total of 1467 articles were identified, of which 845 were excluded. Of the 622 remaining references, 47 met all the search criteria and were included in this review. Conclusion. Several baseline characteristics correlated with anti-VEGF treatment response, including best-corrected visual acuity, age, lesion size, and retinal thickness. The majority of factors were associated with disease duration, suggesting that longer disease duration before treatment results in worse treatment outcomes. This highlights the need for early treatment for patients with nAMD to gain optimal treatment outcomes. Many of the identified baseline characteristics are interconnected and cannot be evaluated in isolation; therefore multivariate analyses will be required to determine any specific relationship with treatment response. PMID:27073691

  13. Choroidal Neovascularization Associated with Punctate Inner Choroidopathy: Combination of Intravitreal Anti-VEGF and Systemic Immunosuppressive Therapy

    PubMed Central

    Hohberger, Bettina; Rudolph, Michael; Bergua, Antonio

    2015-01-01

    Purpose Choroidal neovascularization (CNV) associated with punctate inner choroidopathy (PIC) is a rare clinical entity, yet still a challenge for medical treatment. A case of a young myopic woman developing CNV secondary to unilateral PIC is presented. Clinical morphology, diagnostic procedure and follow-up are reported. Case Report A 29-year-old woman presented with multiple yellowish dots at the posterior pole. No other signs of inflammation could be seen. Angiography with fluorescein yielded hyperfluorescent signals in the affected areas with a diffuse leak, and SD-OCT showed a slightly elevated retinal pigment epithelial layer, consistent with the diagnosis of PIC. Additionally a classic CNV was observed. Results Anti-inflammatory therapy with local prednisolone acetate eye drops in combination with intravitreal injection of anti-vascular endothelial growth factor (VEGF, bevacizumab) yielded an increased best-corrected visual acuity. As CNV reappeared, systemic medication with prednisone and azathioprine in combination with two further intravitreal injections of anti-VEGF stabilized CNV and increased visual acuity again. Conclusion Combined therapy of immunosuppression with intravitreal anti-VEGF injections can be considered as therapeutic strategy in the management of recurrent CNV associated with PIC. PMID:26955337

  14. Oncogenic RAS pathway activation promotes resistance to anti-VEGF therapy through G-CSF–induced neutrophil recruitment

    PubMed Central

    Phan, Vernon T.; Wu, Xiumin; Cheng, Jason H.; Sheng, Rebecca X.; Chung, Alicia S.; Zhuang, Guanglei; Tran, Christopher; Song, Qinghua; Kowanetz, Marcin; Sambrone, Amy; Tan, Martha; Meng, Y. Gloria; Jackson, Erica L.; Peale, Franklin V.; Junttila, Melissa R.; Ferrara, Napoleone

    2013-01-01

    Granulocyte-colony stimulating factor (G-CSF) promotes mobilization of CD11b+Gr1+ myeloid cells and has been implicated in resistance to anti-VEGF therapy in mouse models. High G-CSF production has been associated with a poor prognosis in cancer patients. Here we show that activation of the RAS/MEK/ERK pathway regulates G-CSF expression through the Ets transcription factor. Several growth factors induced G-CSF expression by a MEK-dependent mechanism. Inhibition of G-CSF release with a MEK inhibitor markedly reduced G-CSF production in vitro and synergized with anti-VEGF antibodies to reduce CD11b+Ly6G+ neutrophil mobilization and tumor growth and led to increased survival in animal models of cancer, including a genetically engineered mouse model of pancreatic adenocarcinoma. Analysis of biopsies from pancreatic cancer patients revealed increased phospho-MEK, G-CSF, and Ets expression and enhanced neutrophil recruitment compared with normal pancreata. These results provide insights into G-CSF regulation and on the mechanism of action of MEK inhibitors and point to unique anticancer strategies. PMID:23530240

  15. Optical coherence tomography parameters predictive of visual outcome after anti-VEGF therapy for retinal vein occlusion

    PubMed Central

    Fujihara-Mino, Akiko; Mitamura, Yoshinori; Inomoto, Naoki; Sano, Hiroki; Akaiwa, Kei; Semba, Kentaro

    2016-01-01

    Purpose To determine the optical coherence tomography (OCT) parameters that are predictive of visual outcome after anti-VEGF therapy for a retinal vein occlusion (RVO). Methods Fifty-seven eyes with macular edema (ME) secondary to a central or branch RVO treated with bevacizumab or ranibizumab were studied. Spectral-domain OCT and microperimetry were performed before, 1, 3, and 6 months after the treatment and at the final visit. Central retinal thickness (CRT), macular volume (MV), integrity of the external limiting membrane (ELM), ellipsoid zone (EZ), and foveal bulge (FB), and photoreceptor outer segment (PROS) length were determined. Results The mean follow-up period was 17.8±11.5 months. In 46 of the 57 eyes, a resolution of the ME was achieved. The pretreatment CRT and MV, presence of intact ELM, EZ, and FB, and PROS length at the time of ME resolution were significantly correlated with the best-corrected visual acuity and retinal sensitivity at the final visit (P<0.050). Multiple regression analyses showed that the pretreatment MV had the highest correlation with the posttreatment best-corrected visual acuity and retinal sensitivity (P<0.050). Conclusion The CRT, MV, ELM, EZ, FB, and PROS length are predictive factors for the visual outcome after anti-VEGF therapy for RVO. PMID:27486302

  16. Epidemiological and Clinical Baseline Characteristics as Predictive Biomarkers of Response to Anti-VEGF Treatment in Patients with Neovascular AMD

    PubMed Central

    López-Gálvez, Maria I.; Margaron, Philippe; Lambrou, George N.

    2016-01-01

    Purpose. To review the current literature investigating patient response to antivascular endothelial growth factor-A (VEGF) therapy in the treatment of neovascular age-related macular degeneration (nAMD) and to identify baseline characteristics that might predict response. Method. A literature search of the PubMed database was performed, using the keywords: AMD, anti-VEGF, biomarker, optical coherence tomography, treatment outcome, and predictor. The search was limited to articles published from 2006 to date. Exclusion criteria included phase 1 trials, case reports, studies focusing on indications other than nAMD, and oncology. Results. A total of 1467 articles were identified, of which 845 were excluded. Of the 622 remaining references, 47 met all the search criteria and were included in this review. Conclusion. Several baseline characteristics correlated with anti-VEGF treatment response, including best-corrected visual acuity, age, lesion size, and retinal thickness. The majority of factors were associated with disease duration, suggesting that longer disease duration before treatment results in worse treatment outcomes. This highlights the need for early treatment for patients with nAMD to gain optimal treatment outcomes. Many of the identified baseline characteristics are interconnected and cannot be evaluated in isolation; therefore multivariate analyses will be required to determine any specific relationship with treatment response. PMID:27073691

  17. Anti-EGFR and anti-VEGF agents: important targeted therapies of colorectal liver metastases.

    PubMed

    Feng, Qing-Yang; Wei, Ye; Chen, Jing-Wen; Chang, Wen-Ju; Ye, Le-Chi; Zhu, De-Xiang; Xu, Jian-Min

    2014-04-21

    Colorectal liver metastasis (CLM) is common worldwide. Targeted therapies with monoclonal antibodies have been proven effective in numerous clinical trials, and are now becoming standards for patients with CLM. The development and application of anti-epidermal growth factor receptor (anti-EGFR) and anti-vascular endothelial growth factor (anti-VEGF) antibodies represents significant advances in the treatment of this disease. However, new findings continue to emerge casting doubt on the efficacy of this approach. The Kirsten rat sarcoma viral oncogene (KRAS) has been proven to be a crucial predictor of the success of anti-EGFR treatment in CLM. Whereas a recent study summarized several randomized controlled trials, and showed that patients with the KRAS G13D mutation significantly benefited from the addition of cetuximab in terms of progress-free survival (PFS, 4.0 mo vs 1.9 mo, HR = 0.51, P = 0.004) and overall survival (OS, 7.6 mo vs 5.7 mo, HR = 0.50, P = 0.005). Some other studies also reported that the KRAS G13D mutation might not be absolutely predictive of non-responsiveness to anti-EGFR therapy. At the same time, "new" RAS mutations, including mutations in neuroblastoma RAS viral (v-ras) oncogene homolog (NRAS) and exons 3 and 4 of KRAS, have been suggested to be predictors of a poor treatment response. This finding was first reported by the update of the PRIME trial. The update showed that for patients with non-mutated KRAS exon 2 but other RAS mutations, panitumumab-fluorouracil, leucovorin, and oxaliplatin (FOLFOX)4 treatment led to inferior PFS (HR = 1.28, 95%CI: 0.79-2.07) and OS (HR = 1.29, 95%CI: 0.79-2.10), which was consistent with the findings in patients with KRAS mutations in exon 2. Then, the update of the PEAK trial and the FIRE-III trial also supported this finding, which would reduce candidates for anti-EGFR therapy but enhance the efficacy. In first-line targeted combination therapy, the regimens of cetuximab plus FOLFOX was called into

  18. Rabbit models for the study of human atherosclerosis: from pathophysiological mechanisms to translational medicine.

    PubMed

    Fan, Jianglin; Kitajima, Shuji; Watanabe, Teruo; Xu, Jie; Zhang, Jifeng; Liu, Enqi; Chen, Y Eugene

    2015-02-01

    Laboratory animal models play an important role in the study of human diseases. Using appropriate animals is critical not only for basic research but also for the development of therapeutics and diagnostic tools. Rabbits are widely used for the study of human atherosclerosis. Because rabbits have a unique feature of lipoprotein metabolism (like humans but unlike rodents) and are sensitive to a cholesterol diet, rabbit models have not only provided many insights into the pathogenesis and development of human atherosclerosis but also made a great contribution to translational research. In fact, rabbit was the first animal model used for studying human atherosclerosis, more than a century ago. Currently, three types of rabbit model are commonly used for the study of human atherosclerosis and lipid metabolism: (1) cholesterol-fed rabbits, (2) Watanabe heritable hyperlipidemic rabbits, analogous to human familial hypercholesterolemia due to genetic deficiency of LDL receptors, and (3) genetically modified (transgenic and knock-out) rabbits. Despite their importance, compared with the mouse, the most widely used laboratory animal model nowadays, the use of rabbit models is still limited. In this review, we focus on the features of rabbit lipoprotein metabolism and pathology of atherosclerotic lesions that make it the optimal model for human atherosclerotic disease, especially for the translational medicine. For the sake of clarity, the review is not an attempt to be completely inclusive, but instead attempts to summarize substantial information concisely and provide a guideline for experiments using rabbits. PMID:25277507

  19. Profiling Analysis of Histone Modifications and Gene Expression in Lewis Lung Carcinoma Murine Cells Resistant to Anti-VEGF Treatment

    PubMed Central

    Du, Yanhua; Chen, Kaiming; Liu, Zhenping; Li, Bing; Li, Jie; Tao, Fei; Gu, Hua; Jiang, Cizhong; Fang, Jianmin

    2016-01-01

    Tumor cells become resistant after long-term use of anti-VEGF (vascular endothelial growth factor) agents. Our previous study shows that treatment with a VEGF inhibitor (VEGF-Trap) facilitates to develop tumor resistance through regulating angiogenesis-related genes. However, the underlying molecular mechanisms remain elusive. Histone modifications as a key epigenetic factor play a critical role in regulation of gene expression. Here, we explore the potential epigenetic gene regulatory functions of key histone modifications during tumor resistance in a mouse Lewis lung carcinoma (LLC) cell line. We generated high resolution genome-wide maps of key histone modifications in sensitive tumor sample (LLC-NR) and resistant tumor sample (LLC-R) after VEGF-Trap treatment. Profiling analysis of histone modifications shows that histone modification levels are effectively predictive for gene expression. Composition of promoters classified by histone modification state is different between LLC-NR and LLC-R cell lines regardless of CpG content. Histone modification state change between LLC-NR and LLC-R cell lines shows different patterns in CpG-rich and CpG-poor promoters. As a consequence, genes with different level of CpG content whose gene expression level are altered are enriched in distinct functions. Notably, histone modification state change in promoters of angiogenesis-related genes consists with their expression alteration. Taken together, our findings suggest that treatment with anti-VEGF therapy results in extensive histone modification state change in promoters with multiple functions, particularly, biological processes related to angiogenesis, likely contributing to tumor resistance development. PMID:27362259

  20. Arming embolic beads with anti-VEGF antibodies and controlling their release using LbL technology.

    PubMed

    Sakr, O S; Berndt, S; Carpentier, G; Cuendet, M; Jordan, O; Borchard, G

    2016-02-28

    Transarterial chemoembolization (TACE) is used to treat various types of hypervascular tumors such as hepatocellular carcinoma and renal cancer. However, embolization and blocking of blood vessels nourishing a tumor mass evokes an angiogenic response due to the secretion of vascular endothelial growth factor (VEGF), which results in the formation of new blood vessels and eventually limitation in therapeutic efficacy. The presented work investigates the feasibility of loading the clinically used embolic beads (DC Bead®) with Bevacizumab (BEV), an anti-VEGF antibody, and control its release kinetics via Layer-by-Layer (LbL) coating. This strategy has the aim to achieve high, localized and sustained concentrations of BEV at the tumor site and reduce drug exposure in the systemic circulation. High loading of BEV on lyophilized beads of about 76mg BEV/bead vial was achieved. LbL coating was carried out by depositing alternating layers of the biocompatible polymers alginate and poly-L-lysine. Coating was proven successful by monitoring the reversal of zeta potential after addition of each layer. Morphological changes of the bead surface before and after coating were illustrated using SEM imaging. Moreover, release profiles from different formulations were studied and results showed that optimizing the number of deposited layers effectively slows the release of BEV for three days. Activity of released BEV was studied in different 2D and 3D cell based assays. Released BEV fractions showed comparable activity to fresh BEV solution used as control after 3days. In conclusion, our results suggest the opportunity for loading anti-VEGF antibodies on commercially available embolic beads to increase the efficacy of TACE of hypervascular tumors. PMID:26780173

  1. Post-intravitreal anti-VEGF endophthalmitis in the United Kingdom: incidence, features, risk factors, and outcomes

    PubMed Central

    Lyall, D A M; Tey, A; Foot, B; Roxburgh, S T D; Virdi, M; Robertson, C; MacEwen, C J

    2012-01-01

    Purpose To describe the incidence, features, management, and risk factors of post-intravitreal anti-VEGF endophthalmitis (PIAE) in patients undergoing treatment for exudative age-related macular degeneration in the United Kingdom. Methods Prospective observational case control study. Forty-seven cases of PIAE were identified through the British Ophthalmological Surveillance Unit from January 2009 to March 2010. Data collected at diagnosis and at 6 months follow-up included patient demographics, intravitreal injection details, pre- and post-injection management, visual acuity, clinical features and management of PIAE, causative organisms, and clinical outcomes. Details were compared with 200 control cases from 10 control centres to identify potential risk factors. Results Estimated PIAE was 0.025%. Culture-positive PIAE incidence was 0.015%. Mean age of presentation was 78 years. Mean number of intravitreal injections before PIAE was 5. Mean days to presentation was 5 (range 1–39). Positive microbiology culture was found in 59.6%. The majority of causative organisms were Gram positive (92.8%). Significant risk factors were failure to administer topical antibiotics immediately after the injection (P=0.001), blepharitis (P=0.006), subconjunctival anaesthesia (P=0.021), patient squeezing during the injection (P=0.021), and failure to administer topical antibiotics before anti-VEGF injection (P=0.05). Discussion The incidence of PIAE in the United Kingdom is comparable to other studies at a rate of 0.025%. The most common causative organisms were Gram positive. Measures to minimise the risk of PIAE include treatment of blepharitis before injection, avoidance of subconjunctival anaesthesia, topical antibiotic administration immediately after injection with consideration to administering topical antibiotics before injection. PMID:23060022

  2. Viral haemorrhagic disease of rabbits and human health.

    PubMed Central

    Carman, J. A.; Garner, M. G.; Catton, M. G.; Thomas, S.; Westbury, H. A.; Cannon, R. M.; Collins, B. J.; Tribe, I. G.

    1998-01-01

    Viral haemorrhagic disease of rabbits (VHD), a potential biological control for wild rabbits in Australia and New Zealand, escaped from quarantined field trials on Wardang Island and spread to the mainland of Australia in October 1995. This study looked for any evidence of infection or illness in people occupationally exposed to the virus. Two hundred and sixty-nine people were interviewed and 259 blood samples were collected. Exposures to VHD-infected rabbits ranged from nil to very high. No VHD antibodies were detected in any of the 259 sera when tested by VHD competitive enzyme immunoassay, which had been validated with 1013 VHDV-specific antibody negative sera. A questionnaire designed to elicit symptoms of disease in a range of organ systems found no significant differences between illness in those exposed and those not exposed to VHD, nor could an association be found between exposure and subsequent episodes of illness. The findings are consistent with the view that exposure to VHD is not associated with infection or disease in humans. PMID:9825794

  3. A novel anti-VEGF165 monoclonal antibody-conjugated liposomal nanocarrier system: physical characterization and cellular uptake evaluation in vitro and in vivo.

    PubMed

    Shi, Chenyang; Gao, Fei; Gao, Xiangdong; Liu, Yu

    2015-02-01

    Vascular endothelial growth factor (VEGF) is an important target for cancer therapy. In the present study, we conjugated the novel fully-human anti-VEGF165 monoclonal antibody, mAb165, with a PEGylated liposome (lip) to produce a monoclonal antibody-conjugated PEGylated liposome (mAb-lip). Physical characterization of mAb-lips showed an average particle size of 108nm. Using a bicinchoninic acid (BCA) assay, the coupling efficiency of mAb165 conjugated to the liposome was 69.8±0.5μg mAb/μmol phospholipid. In addition, we confirmed that conjugation between mAb165 and the liposome did not affect the structure and VEGF binding affinity of the antibody. Cell uptake of mAb-lips was assessed in four cell lines: MCF-7, HepG-2, SGC-7901, and L02 cells. Confocal microscopy and flow cytometry demonstrated that there was no significant difference in cell uptake between mAb-lips and mAb-free liposome either in VEGF-expressing tumor cells or normal cells. Moreover, the cytotoxicity of paclitaxel encapsulated in mAb-lips was not increased in the four cell lines. However, in BALB/c nude mice bearing MCF-7 xenografts, mAb-lips showed superior targeting activity to tumor tissues when compared with the unmodified liposome, which was demonstrated by the fact that rhodamine-labeled mAb-lips exhibited higher fluorescence intensity in tumor tissues than the unmodified liposome. Thus, our study indicated that mAb-lips may have the potential to enhance the therapeutic index of anticancer agents through targeted delivery to tumor cells in vivo. PMID:25661357

  4. Src inhibitor reduces permeability without disturbing vascularization and prevents bone destruction in steroid-associated osteonecrotic lesions in rabbits

    PubMed Central

    He, Yi-Xin; Liu, Jin; Guo, Baosheng; Wang, Yi-Xiang; Pan, Xiaohua; Li, Defang; Tang, Tao; Chen, Yang; Peng, Songlin; Bian, Zhaoxiang; Liang, Zicai; Zhang, Bao-Ting; Lu, Aiping; Zhang, Ge

    2015-01-01

    To examine the therapeutic effect of Src inhibitor on the VEGF mediating vascular hyperpermeability and bone destruction within steroid-associated osteonecrotic lesions in rabbits. Rabbits with high risk for progress to destructive repair in steroid-associated osteonecrosis were selected according to our published protocol. The selected rabbits were systemically administrated with either Anti-VEGF antibody (Anti-VEGF Group) or Src inhibitor (Src-Inhibition Group) or VEGF (VEGF-Supplement Group) or a combination of VEGF and Src inhibitor (Supplement & Inhibition Group) or control vehicle (Control Group) for 4 weeks. At 0, 2 and 4 weeks after administration, in vivo dynamic MRI, micro-CT based-angiography, histomorphometry and immunoblotting were employed to evaluate the vascular and skeletal events in different groups. The incidence of the destructive repair in the Anti-VEGF Group, Src-Inhibition Group and Supplement & Inhibition Group was all significantly lower than that in the Control Group. The angiogenesis was promoted in VEGF-Supplement Group, Src-Inhibition Group and Supplement & Inhibition Group, while the hyperpermeability was inhibited in Anti-VEGF Group, Src-Inhibition Group and Supplement & Inhibition Group. The trabecular structure was improved in Src-Inhibition Group and Supplement & Inhibition Group. Src inhibitor could reduce permeability without disturbing vascularization and prevent destructive repair in steroid-associated osteonecrosis. PMID:25748225

  5. [Tear in retinal pigment epithelium under anti-VEGF therapy for exudative age-related macular degeneration : function recovery under intensive therapy].

    PubMed

    Bartels, S; Barrelmann, A; Book, B; Heimes, B; Gutfleisch, M; Spital, G; Pauleikhoff, D; Lommatzsch, A

    2014-05-01

    This article reports the case of a 72-year-old woman with pigment epithelial detachment with occult choroidal neovascularization (CNV) in exudative age-related macular degeneration (AMD) which developed under anti-vascular endothelial growth factor (VEGF) therapy of a tear in the retinal pigment epithelium (RPE). In the area of free RPE autofluorescence was completely absent and the microperimetry in this area showed an absolute scotoma. The visual acuity was 0.1. After continuation of anti-VEGF therapy because of persistent subretinal and intraretinal fluid over 3 years an increased autofluorescence was observed and the microperimetry showed an increase in central retinal sensitivity. The central visual acuity improved to 0.5 and in this area a whitish subretinal tissue formed morphologically. In the spectral domain optical coherence tomography (SD-OCT) image this structure was hyperreflective which might suggest a certain regeneration process of the RPE under anti-VEGF-therapy. PMID:24046170

  6. Gene Therapy with Endogenous Inhibitors of Angiogenesis for Neovascular Age-Related Macular Degeneration: Beyond Anti-VEGF Therapy

    PubMed Central

    Prea, Selwyn M.; Chan, Elsa C.; Dusting, Gregory J.; Vingrys, Algis J.; Bui, Bang V.

    2015-01-01

    Age-related macular degeneration (AMD) is the leading cause of substantial and irreversible vision loss amongst elderly populations in industrialized countries. The advanced neovascular (or “wet”) form of the disease is responsible for severe and aggressive loss of central vision. Current treatments aim to seal off leaky blood vessels via laser therapy or to suppress vessel leakage and neovascular growth through intraocular injections of antibodies that target vascular endothelial growth factor (VEGF). However, the long-term success of anti-VEGF therapy can be hampered by limitations such as low or variable efficacy, high frequency of administration (usually monthly), potentially serious side effects, and, most importantly, loss of efficacy with prolonged treatment. Gene transfer of endogenous antiangiogenic proteins is an alternative approach that has the potential to provide long-term suppression of neovascularization and/or excessive vascular leakage in the eye. Preclinical studies of gene transfer in a large animal model have provided impressive preliminary results with a number of transgenes. In addition, a clinical trial in patients suffering from advanced neovascular AMD has provided proof-of-concept for successful gene transfer. In this mini review, we summarize current theories pertaining to the application of gene therapy for neovascular AMD and the potential benefits when used in conjunction with endogenous antiangiogenic proteins. PMID:25821585

  7. Pharmacokinetics of mitomycin C in rabbit and human.

    PubMed

    van Hazel, G A; Kovach, J S

    1982-01-01

    A sensitive and specific high-pressure liquid chromatographic assay was developed to characterize the plasma elimination and urinary excretion of mitomycin C in humans. Extraction of mitomycin C and an internal standard, porfiromycin, from plasma by chromatography over a non-ionic resin, Porapak Q, yields high recovery of both compounds and facilitates measurement of as little as 5 ng mitomycin C by reversed-phase high-pressure liquid chromatography. The assay was used to characterize the plasma elimination of mitomycin C in rabbits and was shown to be applicable to the characterization of the pharmacokinetics of mitomycin C in humans receiving as little as 8 mg/m2. PMID:6809356

  8. Risk of venous and arterial thromboembolic events associated with anti-VEGF agents in advanced non-small-cell lung cancer: a meta-analysis and systematic review

    PubMed Central

    Zhang, Dianbao; Zhang, Xianfen; Zhao, Chunling

    2016-01-01

    Aims To assess the incidence and risk of arterial and venous thromboembolic events (ATEs and VTEs) associated with antivascular endothelial growth factor (VEGF) agents, including VEGF receptor-tyrosine kinase inhibitors and VEGF monoclonal antibodies, in advanced non-small-cell lung cancer (NSCLC) patients. Methods We performed a broad search of PubMed for relevant trials. Prospective randomized trials evaluating therapy with or without anti-VEGF agents in patients with advanced NSCLC were included for analysis. Data on VTEs and ATEs were extracted. The overall incidence, Peto odds ratio (Peto OR), and 95% confidence intervals (CIs) were pooled according to the heterogeneity of included trials. Results A total of 13,436 patients from 23 trials were included for analysis. Our results showed that anti-VEGF agents significantly increased the risk of developing high-grade ATEs (Peto OR: 1.44, 95% CI: 1.00–2.07, P=0.048), but not for all-grade ATEs (Peto OR: 0.94, 95% CI: 0.56–1.59, P=0.82) compared with controls. Additionally, no increased risk of all-grade and high-grade VTEs (Peto OR: 0.94, 95% CI: 0.67–1.31, P=0.71 and Peto OR: 0.95, 95% CI: 0.73–1.22, P=0.67, respectively) was observed in advanced NSCLC patients receiving anti-VEGF agents. Conclusion The use of anti-VEGF agents in advanced NSCLC patients significantly increased the risk of high-grade ATEs, but not for VTEs. Clinicians should be aware of the risk of severe ATEs with administration of these drugs in advanced NSCLC patients. PMID:27382307

  9. Human apolipoprotein A-II protects against diet-induced atherosclerosis in transgenic rabbits

    PubMed Central

    Wang, Yao; Niimi, Manabu; Nishijima, Kazutoshi; Waqar, Ahmed Bilal; Yu, Ying; Koike, Tomonari; Kitajima, Shuji; Liu, Enqi; Inoue, Tomohiro; Kohashi, Masayuki; Keyamura, Yuka; Yoshikawa, Tomohiro; Zhang, Jifeng; Ma, Loretta; Zha, Xiaohui; Watanabe, Teruo; Asada, Yujiro; Chen, Y. Eugene; Fan, Jianglin

    2013-01-01

    Objective Apolipoprotein A-II (apo A-II) is the second major apolipoprotein of HDLs, yet its pathophysiological roles in the development of atherosclerosis remain unknown. We aimed to examine whether apo A-II plays any role in atherogenesis and if so, to elucidate the mechanism involved. Methods and Results We compared the susceptibility of human apo A-II transgenic (Tg) rabbits to cholesterol diet-induced atherosclerosis with non-Tg littermate rabbits. Tg rabbits developed significantly less aortic and coronary atherosclerosis than their non-Tg littermates while total plasma cholesterol levels were similar. Atherosclerotic lesions of Tg rabbits were characterized by reduced macrophages and smooth muscle cells and apo A-II immunoreactive proteins were frequently detected in the lesions. Tg rabbits exhibited low levels of plasma CRP and blood leukocytes compared to non-Tg rabbits and HDLs of Tg rabbit plasma exerted stronger cholesterol efflux activity and inhibitory effects on the inflammatory cytokine expression by macrophages in vitro than HDLs isolated from non-Tg rabbits. In addition, β-VLDLs of Tg rabbits were less sensitive to copper-induced oxidation than β-VLDLs of non-Tg rabbits. Conclusions These results suggest that enrichment of apo A-II in HDL particles has atheroprotective effects and apo A-II may become a target for the treatment of atherosclerosis. PMID:23241412

  10. Outcomes of 23-Gauge Vitrectomy Combined with Phacoemulsification, Panretinal Photocoagulation, and Trabeculectomy without Use of Anti-VEGF Agents for Neovascular Glaucoma with Vitreous Hemorrhage

    PubMed Central

    Yan, Hua

    2016-01-01

    Purpose. To evaluate the outcomes of 23-gauge vitrectomy combined with phacoemulsification, PRP and trabeculectomy without use of anti-VEGF-agents for NVG. Methods. Eighteen eyes of 18 patients with NVG underwent 23-gauge vitrectomy combined with phacoemulsification, PRP and trabeculectomy without use of anti-VEGF agents. The preoperative BCVA ranged from light perception to 0.2. The preoperative IOP ranged from 38 mmHg to 64 mmHg with a mean of 54 ± 8 mmHg. The average follow-up time was 14.5 ± 3 months with a range from 11 to 24 months. Results. The postoperative VA increased in 14 eyes and was stable in 4 eyes at the final follow-up. The mean IOP was 12 ± 3 mmHg at postoperative day 1. The mean IOP was 15 ± 2 mmHg, 16 ± 3 mmHg, 23 ± 5 mmHg, 28 ± 4 mmHg, 22 ± 5 mmHg, 17 ± 3 mmHg, and 19 ± 4 mmHg at postoperative days 2 and 3, 1, 2, 3, and 12 weeks, and 1 year postoperatively, respectively, with a range from 10 to 30 mmHg at the final follow-up time point of one year. The IOP was significantly lower than the preoperative one 12 weeks postoperatively (p < 0.05). Conclusion. 23-gauge vitrectomy combined with phacoemulsification, PRP, and trabeculectomy without use of anti-VEGF-agents is a safe and effective method in treating NVG. PMID:26885379

  11. The permeability of rabbit and human corneal endothelium.

    PubMed Central

    Hodson, S; Wigham, C

    1983-01-01

    The fluxes of sodium, chloride and bicarbonate across endothelium plus stroma and then stroma alone were measured in the direction from lens-side to tear-side in rabbit and human corneas in vitro, in order to measure passive permeabilities. The results were used to calculate the permeability of the endothelium. Hodgkin's equation (1951) was then used to calculate the partial electrical conductivity of each ion crossing the endothelium. The summated electrical conductivities of sodium, chloride and bicarbonate were equal to 89 +/- 8% of the measured electrical conductivity, suggesting that the ions diffuse independently across the endothelium in the direction lens-side to tear-side. Stereological analysis of the intercellular spaces supports the idea that the ions permeate through this route and that the physical shape of the spaces determines almost entirely the permeability of the endothelial layer. Trans-endothelial sodium and chloride permeabilities are nearly equal, which may be explained by supposing the intercellular spaces include a cation exchanger of fixed negative charge capacity around 60 m-equiv l.-1 intercellular fluid. PMID:6631742

  12. Short-term Efficacy of Intravitreal Dexamethasone Implant in Vitrectomized Eyes with Recalcitrant Diabetic Macular Edema and Prior Anti-VEGF Therapy

    PubMed Central

    Shah, Ankoor R.; Xi, Mengqiao; Abbey, Ashkan M.; Yonekawa, Yoshihiro; Faia, Lisa J.; Hassan, Tarek S.; Ruby, Alan J.; Wolfe, Jeremy D.

    2016-01-01

    Purpose: To determine the efficacy of an intravitreal dexamethasone implant (IDI) for diabetic macular edema (DME) in vitrectomized eyes. Methods: This interventional retrospective consecutive case series included vitrectomized eyes undergoing IDI placement for treatment of recalcitrant DME between June 2011 and June 2014. All patients had previously received anti-VEGF therapy (ranibizumab or bevacizumab). Primary endpoints were changes in visual acuity (VA) and central retinal thickness (CRT) from baseline values one month after device implantation. Secondary endpoints were VA and CRT changes at 3 months. Results: A total of 8 eyes of 8 patients met the inclusion criteria. One month after IDI placement, there was a significant (p = 0.01) improvement in VA from 0.79 ± 0.52 logMAR (20/123 Snellen equivalent) to 0.64 ± 0.55 logMAR (20/88), meanwhile CRT improved from 455.75 ± 123.19 to 295.00 ± 90.39 μm (p = 0.02). These findings persisted at 3 months. Conclusion: In vitrectomized eyes previously treated with anti-VEGF agents for recalcitrant DME, implantation of the IDI appears to be efficacious in improving VA and CRT at 1-month with the observed benefits persisting for at least for 3 months. PMID:27413499

  13. Human-derived nanoparticles and vascular response to injury in rabbit carotid arteries: proof of principle.

    PubMed

    Schwartz, Maria A K; Lieske, John C; Kumar, Vivek; Farell-Baril, Gerard; Miller, Virginia M

    2008-01-01

    Self-calcifying, self-replicating nanoparticles have been isolated from calcified human tissues. However, it is unclear if these nanoparticles participate in disease processes. Therefore, this study was designed to preliminarily test the hypothesis that human-derived nanoparticles are causal to arterial disease processes. One carotid artery of 3 kg male rabbits was denuded of endothelium; the contralateral artery remained unoperated as a control. Each rabbit was injected intravenously with either saline, calcified, or decalcified nanoparticles cultured from calcified human arteries or kidney stones. After 35 days, both injured and control arteries were removed for histological examination. Injured arteries from rabbits injected with saline showed minimal, eccentric intimal hyperplasia. Injured arteries from rabbits injected with calcified kidney stone- and arterial-derived nanoparticles occluded, sometimes with canalization. The calcified kidney stone-derived nanoparticles caused calcifications within the occlusion. Responses to injury in rabbits injected with decalcified kidney stone-derived nanoparticles were similar to those observed in saline-injected animals. However, decalcified arterial-derived nanoparticles produced intimal hyperplasia that varied from moderate to occlusion with canalization and calcification. This study offers the first evidence that there may be a causal relationship between human-derived nanoparticles and response to injury including calcification in arteries with damaged endothelium. PMID:18686783

  14. Early treatment of acute submacular haemorrhage secondary to wet AMD using intravitreal tissue plasminogen activator, C3F8, and an anti-VEGF agent.

    PubMed

    de Silva, S R; Bindra, M S

    2016-07-01

    PurposeAcute submacular haemorrhage secondary to wet age-related macular degeneration (AMD) has a poor prognosis for which there is currently no 'gold standard' treatment. We evaluated the efficacy of early treatment using intravitreal triple therapy of tissue plasminogen activator (tPA), expansile gas, and an anti-VEGF agent.MethodsThis retrospective case series included eight patients presenting with acute submacular haemorrhage involving the fovea. All patients received treatment with 50 μg (0.05 ml) tPA, 0.3 ml 100% perfluoropropane (C3F8), and an anti-VEGF agent (0.05 mg Ranibizumab or 1.25 mg Bevacizumab in 0.05 ml) administered via intravitreal injection. An anterior chamber paracentesis post injection or vitreous tap was performed before injection to prevent retinal vascular occlusion secondary to raised intra-ocular pressure. Outcomes assessed were visual acuity, change in macular morphology, and complications.ResultsPatients presented promptly with delay between symptom onset and clinic review being 1.9±0.6 days (mean±SD). Treatment was delivered quickly with interval from presentation to treatment being 1.1±1.2 days. Symptom onset to treatment was 3.0±1.0 days. Subfoveal haemorrhage was effectively displaced in all patients. LogMAR visual acuity improved from 1.67±0.47 at presentation to 0.63±0.33 at final follow-up (P<0.0001), a mean of 7.9±4.8 months after treatment. Central retinal thickness improved from 658.1±174.2 μm at presentation to 316.6±142.4 μm at final follow-up (P=0.0028).ConclusionsEarly treatment of submacular haemorrhage using intravitreal tPA, C3F8, and anti-VEGF was effective in significantly improving visual acuity in this series of patients who presented soon after symptom onset. Treatment was well tolerated in this group of elderly and potentially frail patients. PMID:27080482

  15. Pharmacogenetics of Complement Factor H Y402H Polymorphism and Treatment of Neovascular AMD with Anti-VEGF Agents: A Meta-Analysis

    PubMed Central

    Chen, Guohai; Tzekov, Radouil; Li, Wensheng; Jiang, Fangzheng; Mao, Sihong; Tong, Yuhua

    2015-01-01

    The purpose of this study is to investigate whether the Y402H polymorphism (rs1061170, a T-to-C transition at amino acid position 402) in the complement factor H (CFH) gene have a pharmacogenetics effect on the anti-vascular endothelial growth factor (VEGF) treatment for neovascular age-related macular degeneration (AMD). We performed a meta-analysis using databases including PubMed and EMBASE to find relevant studies. 13 published association studies were selected for this meta-analysis, including 2704 patients. For the CFH Y402H polymorphism, anti-VEGF treatment was much less effective in AMD patients with the CFH CC genotype (CC versus TT: odds ratio (OR) = 55, 95% confidence interval (CI), 0.31 to 0.95, P = 0.03; CC versus CT: OR = 0.60, 95% CI, 0.40 to 0.91, P = 0.02; and CC versus CT + TT: OR = 0.59, 95% CI, 0.38 to 0.90, P = 0.02, respectively). In subgroup analysis, CFH Y402H polymorphism was more likely to be a predictor of response for Caucasians (CC versus CT+TT: OR = 0.63, 95% CI, 0.42 to 0.95, P = 0.03). In conclusion, pharmacogenetics of CFH Y402H polymorphism may play a role in response to anti-VEGF treatment for neovascular AMD, especially for Caucasians. PMID:26411831

  16. Modulated cellular delivery of anti-VEGF siRNA (bevasiranib) by incorporating supramolecular assemblies of hydrophobically modified polyamidoamine dendrimer in stealth liposomes.

    PubMed

    Golkar, Nasim; Samani, Soliman Mohammadi; Tamaddon, Ali Mohammad

    2016-08-20

    A novel lipopolymer based system was designed and characterized for cellular delivery of anti-VEGF siRNA in SKBR-3 breast tumor cell line. Polyamidoamine (PAMAM) dendrimers of low generations (G1, G2 and G3) were incorporated into polyethylene glycol (PEG)-stabilized liposomes by following the consecutive steps: (a) synthesis of the cholesterol conjugates (40% molar ratio of cholesterol to primary amines of PAMAM), (b) incorporation of the conjugates in liposome by lipid mixing and (c) microencapsulation of the siRNA using the ethanol drop method. The cholesterol conjugates of PAMAM dendrimers (G1-Chol40%, G2-Chol40% and G3-Chol40%) formed self assembly with low CMC values (<11μg/ml). Not only did G2-Chol40% show the highest lipid mixing among the cholesterol conjugates, but also, had the lowest leakage of encapsulated carboxyfluorescein tracer. Various N(amine))/L(lipid)/P(phosphate) mole ratios were investigated for siRNA condensation by ethidium bromide dye exclusion assay. The optimum N/L/P ratio of 20:33:10 was chosen for microencapsulation of anti-VEGF siRNA by ethanol drop method, showing particle size of 130nm, zeta-potential of +4mV, siRNA loading efficiency and capacity of 96% and 13wt%, and high stability against heparin sulfate (extracellular matrix). TEM shows uniform and discrete oligo- or multi-lamellar vesicular structures. The liposome incorporating G2-Chol40% was successfully internalized into SKBR-3 cells mainly through clathrin-mediated endocytosis, which was able to escape from endosomes and showed a significantly higher sequence-specific inhibition of VEGF expression and cell growth than the respective G2-Chol40%/siRNA dendriplexes. Importantly, the cytotoxicity decreased with incorporation of G2-Chol40% in the liposomes. PMID:27291973

  17. Predicting vision gains with anti-VEGF therapy in neovascular age-related macular degeneration patients by using low-luminance vision

    PubMed Central

    Frenkel, Ronald E P; Shapiro, Howard; Stoilov, Ivaylo

    2016-01-01

    Background/aims To evaluate baseline low-luminance visual acuity (LLVA) as a predictor of visual acuity improvement in patients with neovascular (wet) age-related macular degeneration (wAMD) receiving antivascular endothelial growth factor A (anti-VEGF) therapy. Methods In the HARBOR trial, 1084 treatment-naïve patients ≥50 years of age with subfoveal wAMD received intravitreal ranibizumab 0.5 or 2.0 mg monthly or as needed. To measure LLVA, patients read a normally illuminated ETDRS (Early Treatment Diabetic Retinopathy Study) chart with a neutral density filter placed in front of the study eye. Patients were assigned into quartiles based on the magnitude of the difference between best-corrected visual acuity under optimal luminance (BCVA) and LLVA (BCVA–LLVA gap). The association between mean change in BCVA from baseline and BCVA–LLVA gap at baseline was analysed using a general linear model. Results A smaller baseline BCVA–LLVA gap predicted significantly higher BCVA gains over 24 months (p<0.0001 at each month; Pearson correlation), even after controlling for baseline BCVA or stratifying by treatment arm. Patients in the smallest baseline BCVA–LLVA gap quartile gained an average of +13.4 letters compared with +2.4 letters for patients in the widest baseline BCVA–LLVA gap quartile. At months 12 and 24, the smallest baseline BCVA–LLVA gap quartile had the highest proportion of ≥15−≥30-letter gain, and the widest baseline BCVA–LLVA gap quartile had the highest proportion of ≥15-/≥30-letter loss (p<0.0001; Fisher's exact test). Conclusions The baseline BCVA–LLVA gap is a significant predictor of visual acuity response to anti-VEGF treatment in patients with wAMD. Trial registration number NCT00891735; Post-results. PMID:26541435

  18. In vitro glutathione conjugation of methyl iodide in rat, rabbit, and human blood and tissues.

    PubMed

    Poet, Torka S; Wu, Hong; Corley, Richard A; Thrall, Karla D

    2009-05-01

    Methyl iodide (MeI) is an intermediate in the manufacture of some pesticides and pharmaceuticals, and is under review for US registration as a non-ozone depleting alternative for methyl bromide for pre-plant soil fumigation. MeI is primarily metabolized via conjugation with glutathione (GSH), with further metabolism to S-methyl cysteine and methanethiol. To facilitate extrapolations of animal pharmacokinetic data to humans, rate constants for the GSH metabolism of MeI were determined in cytosols prepared from the liver and kidneys of rats, human donors, female rabbits, and rabbit fetuses, from rabbit olfactory and respiratory epithelium, and from rabbit and rat blood using a headspace vial equilibration technique and two-compartment mathematical model. MeI was metabolized in liver and kidney from adults of all three species, but metabolism was not detectable in fetal rabbit kidney. Maximal metabolic rates (V(max)) were similar in liver from rat and human donors (approximately 40 and 47 nmol/min/mg, respectively) whereas the V(max) rates in kidney cytosols varied approximately three-fold between the three species. No difference was observed in the loss of MeI from active and inactive whole blood from either rats or rabbits. The metabolism in olfactory and respiratory epithelial cytosol had Michaelis-Menten constant (K(m)) values that were several times higher than for any other tissue, suggesting essentially first-order metabolism in the nose. The metabolism of MeI in human liver cytosol prepared from five individual donors indicated two potential populations, one high affinity/low capacity and one with a lower affinity but higher capacity. PMID:19519152

  19. A rabbit model of human familial, nonsyndromic unicoronal suture synostosis. II. Intracranial contents, intracranial volume, and intracranial pressure.

    PubMed

    Mooney, M P; Siegel, M I; Burrows, A M; Smith, T D; Losken, H W; Dechant, J; Cooper, G; Fellows-Mayle, W; Kapucu, M R; Kapucu, L O

    1998-06-01

    This two-part study reviews data from a recently developed colony of New Zealand white rabbits with familial, nonsyndromic unilateral coronal suture synostosis, and this second part presents neuropathological findings and age-related changes in intracranial volume (ICV) and intracranial pressure (ICP) in 106 normal rabbits and 56 craniosynostotic rabbits from this colony. Brain morphology and anteroposterior length were described in 44 rabbit fetuses and perinates (27 normal; 17 synostosed). Middle meningeal artery patterns were qualitatively assessed from 2-D PCC MRI VENC scans and endocranial tracings from 15, 126-day-old rabbits (8 normal, 7 rabbits with unicoronal synostosis). Brain metabolism was evaluated by assessing 18F-FDG uptake with high-resolution PET scanning in 7, 25-day-old rabbits (3 normal, 4 with unicoronal or bicoronal synostosis). Intracranial contents and ICV were assessed using 3-D CT scanning of the skulls of 30 rabbits (20 normal,10 with unicoronal synostosis) at 42 and 126 days of age. Serial ICP data were collected from 66 rabbits (49 normal; 17 with unicoronal synostosis) at 25 and 42 days of age. ICP was assessed in the epidural space using a Codman NeuroMonitor microsensor transducer. Results revealed that cerebral cortex morphology was similar between normal and synostosed fetuses around the time of synostosis. Significantly (P<0.05) decreased A-P cerebral hemisphere growth rates and asymmetrical cortical remodeling were noted with increasing age in synostotic rabbits. In addition, rabbits with unicoronal suture synostosis exhibited asymmetrical middle meningeal artery patterns, decreased and asymmetrical brain metabolism, a "beaten-copper" intracranial appearance, significantly (P<0.05) decreased ICV, and significantly (P<0.01) elevated ICP compared with normal control rabbits. The advantages and disadvantages of these rabbits as a model for human familial, nonsyndromic unicoronal suture synostosis are discussed, especially in light

  20. Calcium transient and sodium-calcium exchange current in human versus rabbit sinoatrial node pacemaker cells.

    PubMed

    Verkerk, Arie O; van Borren, Marcel M G J; Wilders, Ronald

    2013-01-01

    There is an ongoing debate on the mechanism underlying the pacemaker activity of sinoatrial node (SAN) cells, focusing on the relative importance of the "membrane clock" and the "Ca(2+) clock" in the generation of the small net membrane current that depolarizes the cell towards the action potential threshold. Specifically, the debate centers around the question whether the membrane clock-driven hyperpolarization-activated current, I f , which is also known as the "funny current" or "pacemaker current," or the Ca(2+) clock-driven sodium-calcium exchange current, I NaCa, is the main contributor to diastolic depolarization. In our contribution to this journal's "Special Issue on Cardiac Electrophysiology," we present a numerical reconstruction of I f and I NaCa in isolated rabbit and human SAN pacemaker cells based on experimental data on action potentials, I f , and intracellular calcium concentration ([Ca(2+)] i ) that we have acquired from these cells. The human SAN pacemaker cells have a smaller I f , a weaker [Ca(2+)] i transient, and a smaller I NaCa than the rabbit cells. However, when compared to the diastolic net membrane current, I NaCa is of similar size in human and rabbit SAN pacemaker cells, whereas I f is smaller in human than in rabbit cells. PMID:23606816

  1. Smooth muscle and purinergic contraction of the human, rabbit, rat, and mouse testicular capsule.

    PubMed

    Banks, Frederick C L; Knight, Gillian E; Calvert, Robert C; Turmaine, Mark; Thompson, Cecil S; Mikhailidis, Dimitri P; Morgan, Robert J; Burnstock, Geoffrey

    2006-03-01

    The smooth-muscle cells of the testicular capsule (tunica albuginea) of man, rat, and mouse were examined by electron microscopy. They were characteristically flattened, elongated, branching cells and diffusely incorporated into the collagenous matrix and did not form a compact muscle layer. Contractile and synthetic smooth-muscle cell phenotypes were identified. Nerve varicosities in close apposition to smooth muscle were seen in human tissue. Contractions induced by adenosine 5'-triphosphate (ATP), alpha, beta-methylene ATP, noradrenaline (NA), acetylcholine (ACh), and electrical field stimulation (EFS) of autonomic nerves were investigated. Nerve-mediated responses of the rabbit and human tunica albuginea were recorded. The EFS-induced human responses were completely abolished by prazosin. In the rabbit, EFS-induced contractile responses were reduced by pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid by 36% and by prazosin by 77%. Both antagonists together almost completely abolished all EFS-induced contractions. The human tunica albuginea was contracted by NA, ATP, and alpha, beta-methylene ATP, but not by ACh. The rabbit and rat tunica albuginea were contracted by NA, ATP, alpha, beta-methylene ATP, and ACh. The mouse tunica albuginea was contracted by ACh, ATP, and alpha, beta-methylene ATP, but relaxed to NA. Immunohistochemical studies showed that P2X1 (also known as P2RX1) and P2X2 (also known as P2RX2) receptors were expressed on the smooth muscle of the rodent testicular capsule, expression being less pronounced in man. The testicular capsule of the rat, mouse, rabbit, and man all contain contractile smooth muscle. ATP, released as a cotransmitter from sympathetic nerves, can stimulate the contraction of rabbit smooth muscle. Human, rat, and mouse testicular smooth muscle demonstrated purinergic responsiveness, probably mediated through the P2X1 and/or P2X2 receptors. PMID:16280417

  2. Experimental observation of human bone marrow mesenchymal stem cell transplantation into rabbit intervertebral discs

    PubMed Central

    Tao, Hao; Lin, Yazhou; Zhang, Guoqing; Gu, Rui; Chen, Bohua

    2016-01-01

    Allogeneic bone marrow mesenchymal stem cell (BMSC) transplantation has been investigated worldwide. However, few reports have addressed the survival status of human BMSCs in the intervertebral discs (IVDs) in vivo following transplantation. The current study aimed to observe the survival status of human BMSCs in rabbit IVDs. The IVDs of 15 New Zealand white rabbits were divided into three groups: Punctured blank control group (L1-2); punctured physiological saline control group (L2-3); and punctured human BMSCs transfected with green fluorescent protein (GFP) group (L3-4, L4-5 and L5-6). One, 2, 4, 6 and 8 weeks after transplantation the IVDs were removed and a fluorescence microscope was used to observe the density of GFP-positive human BMSCs. The results indicated that in the sections of specimens removed at 1, 2, 4, 6 and 8 weeks post-transplantation, no GFP-positive cells were observed in the control groups, whereas GFP-positive cells were apparent in the nucleus pulposus at all periods in the GFP-labeled human BMSCs group, and the cell density at 6 and 8 weeks was significantly less than that at 1, 2 and 4 weeks post-transplantation (P<0.001). Thus, it was identified that human BMSCs were able to survive in the rabbit IVDs for 8 weeks. PMID:27588177

  3. The pharmacokinetics of phenylethyl alcohol (PEA): safety evaluation comparisons in rats, rabbits, and humans.

    PubMed

    Politano, Valerie T; Diener, Robert M; Christian, Mildred S; Hawkins, David R; Ritacco, Gretchen; Api, Anne Marie

    2013-01-01

    The present studies were conducted to compare the dermal absorption, plasma pharmacokinetics, and excretion of phenylethyl alcohol (PEA) by pregnant and nonpregnant rats, rabbits, and humans. The PEA is a natural fragrance material that is widely used in perfumes, soaps, and lotions and is a major ingredient of natural rose oil. Following dermal (430, 700, or 1400 mg/kg body weight [bw]), gavage (430 mg/kg bw), or dietary (430 mg/kg bw) administration of PEA to rats, plasma concentrations of PEA were found to be low regardless of the route of administration. The plasma concentrations of phenylacetic acid (PAA, the major metabolite of PEA) greatly exceeded the concentrations of PEA and were highest after gavage, followed by dermal then dietary administration. Absorption, distribution, metabolism, and excretion were compared following topical application of ¹⁴C-labeled PEA to rats, rabbits, and humans (specific activities of dosing solutions: 58-580, 164, and 50 µCi/mL, respectively). In rabbits, the plasma concentration-time profile for PAA was markedly prolonged compared to rats or humans. In humans, only 7.6% of the applied dose of PEA was absorbed, versus 77% in rats and 50% in rabbits. Based on a human dermal systemic exposure of 0.3 mg/kg per day from the use of multiple consumer personal care products containing PEA, a rat dermal no observed adverse effect level of 70 mg/kg per day, and the percentage of dose absorbed in humans, the margin of safety exceeds 2600 concluding that, under normal fragrance use conditions, PEA is not a developmental toxicity hazard for humans. PMID:23385160

  4. Rabbit Neonates and Human Adults Perceive a Blending 6-Component Odor Mixture in a Comparable Manner

    PubMed Central

    Sinding, Charlotte; Thomas-Danguin, Thierry; Chambault, Adeline; Béno, Noelle; Dosne, Thibaut; Chabanet, Claire; Schaal, Benoist; Coureaud, Gérard

    2013-01-01

    Young and adult mammals are constantly exposed to chemically complex stimuli. The olfactory system allows for a dual processing of relevant information from the environment either as single odorants in mixtures (elemental perception) or as mixtures of odorants as a whole (configural perception). However, it seems that human adults have certain limits in elemental perception of odor mixtures, as suggested by their inability to identify each odorant in mixtures of more than 4 components. Here, we explored some of these limits by evaluating the perception of three 6-odorant mixtures in human adults and newborn rabbits. Using free-sorting tasks in humans, we investigated the configural or elemental perception of these mixtures, or of 5-component sub-mixtures, or of the 6-odorant mixtures with modified odorants' proportion. In rabbit pups, the perception of the same mixtures was evaluated by measuring the orocephalic sucking response to the mixtures or their components after conditioning to one of these stimuli. The results revealed that one mixture, previously shown to carry the specific odor of red cordial in humans, was indeed configurally processed in humans and in rabbits while the two other 6-component mixtures were not. Moreover, in both species, such configural perception was specific not only to the 6 odorants included in the mixture but also to their respective proportion. Interestingly, rabbit neonates also responded to each odorant after conditioning to the red cordial mixture, which demonstrates their ability to perceive elements in addition to configuration in this complex mixture. Taken together, the results provide new insights related to the processing of relatively complex odor mixtures in mammals and the inter-species conservation of certain perceptual mechanisms; the results also revealed some differences in the expression of these capacities between species putatively linked to developmental and ecological constraints. PMID:23341948

  5. Characterization of cDNA clones encoding rabbit and human serum paraoxonase: The mature protein retains its signal sequence

    SciTech Connect

    Hassett, C.; Richter, R.J.; Humbert, R.; Omiecinski, C.J.; Furlong, C.E. ); Chapline, C.; Crabb, J.W. )

    1991-10-22

    Serum paraoxonase hydrolyzes the toxic metabolites of a variety of organophosphorus insecticides. High serum paraoxonase levels appear to protect against the neurotoxic effects of organophosphorus substrates of this enzyme. The amino acid sequence accounting for 42% of rabbit paraoxonase was determined. From these data, two oligonucleotide probes were synthesized and used to screen a rabbit liver cDNA library. Human paraoxonase clones were isolated from a liver cDNA library by using the rabbit cDNA as a hybridization probe. Inserts from three of the longest clones were sequenced, and one full-length clone contained an open reading frame encoding 355 amino acids, four less than the rabbit paraoxonase protein. Amino-terminal sequences derived from purified rabbit and human paraoxonase proteins suggested that the signal sequence is retained, with the exception of the initiator methionine residue. Characterization of the rabbit and human paraoxonase cDNA clones confirms that the signal sequences are not processed, except for the N-terminal methionine residue. The rabbit and human cDNA clones demonstrate striking nucleotide and deduced amino acid similarities (greater than 85%), suggesting an important metabolic role and constraints on the evolution of this protein.

  6. Biotransformation of deramciclane in primary hepatocytes of rat, mouse, rabbit, dog, and human.

    PubMed

    Monostory, Katalin; Kohalmy, Krisztina; Ludányi, Krisztina; Czira, Gábor; Holly, Sándor; Vereczkey, László; Urmös, Iván; Klebovich, Imre; Kóbori, László

    2005-11-01

    The metabolic fate of deramciclane [(1R,2S,4R)-(-)-2-phenyl-2-(2'-dimethylamino-ethoxy)-1,7,7-trimethyl-bicyclo[2.2.1]heptane], a new anxiolytic drug candidate, has been determined in rat, mouse, rabbit, dog, and human hepatocytes. Rat and rabbit cells were the most active, whereas the rate of metabolism was quite slow in human hepatocytes. During biotransformation, deramciclane underwent side chain modification and oxidation at several positions of the molecule. The side chain modification led to the formation of N-desmethyl deramciclane and phenylborneol. The oxidation of deramciclane resulted in several hydroxy-, carboxy-, and N-oxide derivatives. The hydroxylation took place at primary or secondary carbons of the camphor ring as well as at the side chain; furthermore, dihydroxylated derivatives were also found. The side chain-modified metabolites were also oxidized to hydroxy- or carboxy-derivatives. Conjugation of phase I metabolites, as a route of elimination, was also observed in rat, rabbit, and dog hepatocytes. Although there were some species differences in biotransformation of deramciclane, it was concluded that phase I metabolism in human liver cells seemed to be similar to the metabolism in the hepatocytes isolated from rat. With careful approach, the rat model may be considered to be predictive for human metabolism of deramciclane. PMID:16118331

  7. Intravenous transferrin, RGD peptide and dual-targeted nanoparticles enhance anti-VEGF intraceptor gene delivery to laser-induced CNV

    PubMed Central

    Singh, SR; Grossniklaus, HE; Kang, SJ; Edelhauser, HF; Ambati, BK; Kompella, UB

    2010-01-01

    Choroidal neovascularization (CNV) leads to loss of vision in age-related macular degeneration (AMD), the leading cause of blindness in adult population over 50 years old. In this study, we developed intravenously administered, nanoparticulate, targeted nonviral retinal gene delivery systems for the management of CNV. CNV was induced in Brown Norway rats using a 532 nm laser. We engineered transferrin, arginine–glycine–aspartic acid (RGD) peptide or dual-functionalized poly-(lactide-co-glycolide) nanoparticles to target delivery of anti-vascular endothelial growth factor (VEGF) intraceptor plasmid to CNV lesions. Anti-VEGF intraceptor is the only intracellularly acting VEGF inhibitory modality. The results of the study show that nanoparticles allow targeted delivery to the neovascular eye but not the control eye on intravenous administration. Functionalizing the nanoparticle surface with transferrin, a linear RGD peptide or both increased the retinal delivery of nanoparticles and subsequently the intraceptor gene expression in retinal vascular endothelial cells, photoreceptor outer segments and retinal pigment epithelial cells when compared to nonfunctionalized nanoparticles. Most significantly, the CNV areas were significantly smaller in rats treated with functionalized nanoparticles as compared to the ones treated with vehicle or nonfunctionalized nanoparticles. Thus, surface-functionalized nanoparticles allow targeted gene delivery to the neovascular eye on intravenous administration and inhibit the progression of laser-induced CNV in a rodent model. PMID:19194480

  8. Can Fluorine-18-Fluorodeoxyglucose Positron Emission Tomography Be Used As a Useful Method to Evaluate the Treatment Response to Neoadjuvant Therapy Combined With Sorafenib and Anti-VEGF in Children Diagnosed With Metastatical Bone Sarcoma?

    PubMed Central

    Tacyildiz, Nurdan; Tanyildiz, Hikmet Gulsah; Dincaslan, Handan Ugur; Yavuz, Gulsan; Unal, Emel; Ozkan, Elgin; Soydal, Cigdem; Kucuk, Ozlem; Yildiz, Yusuf

    2016-01-01

    Background The prognosis is still poor for patients with a metastatic bone tumor and new treatment approaches (anti-VEGF and tyrosine kinase inhibitors vs) are therefore needed. Objectives The aim of our study was to evaluate how the primary and metastatic lesions of our patients with a bone tumor were affected by these treatments and to determine the importance of the 18F-FDG PET method. Patients and Methods Twenty metastatic bone tumor cases were included. Sorafenib and anti-VEGF were added to the standard treatment in cases with widespread metastatic disease at diagnosis or after neoadjuvant chemotherapy showing less than 90% tumor necrosis in the surgical sample. Positron emission tomography (PET) imaging was performed at diagnosis, the preoperative period following neoadjuvant chemotherapy, during postoperative follow-up, and when treatment was discontinued. Results The primary treatment region median SUVmax level decreased from 7.35 to 2.5 in the living patients (n = 16) while there was no significant decrease in the patients who succumbed to the disease (P < 0.001). Comparison of the pre- and post-treatment metastasis region median SUVmax levels in patients with metastatic involvement showed a decrease from 2.1 to 0 in the surviving patients but only from 4.8 to 3.2 in the deceased patients (P < 0.01). Survival results indicated that 28.6% of the patients receiving classical treatment only died while all the patients receiving additional sorafenib and anti-VEGF survived. Conclusions 18F-PET may be a useful technique before and during the follow-up of neoadjuvant treatment in pediatric metastatic bone tumor patients. The addition of sorafenib and anti-VEGF to classical treatment has a favorable contribution to the response and therefore the survival duration. PMID:27307968

  9. Human Adipose-Derived Mesenchymal Progenitor Cells Engraft into Rabbit Articular Cartilage

    PubMed Central

    Wang, Wen; He, Na; Feng, Chenchen; Liu, Victor; Zhang, Luyi; Wang, Fei; He, Jiaping; Zhu, Tengfang; Wang, Shuyang; Qiao, Weiwei; Li, Suke; Zhou, Guangdong; Zhang, Li; Dai, Chengxiang; Cao, Wei

    2015-01-01

    Mesenchymal stem cells (MSCs) are known to have the potential for articular cartilage regeneration, and are suggested for the treatment of osteoarthritis (OA). Here, we investigated whether intra-articular injection of xenogeneic human adipose-derived mesenchymal progenitor cells (haMPCs) promoted articular cartilage repair in rabbit OA model and engrafted into rabbit articular cartilage. The haMPCs were cultured in vitro, and phenotypes and differentiation characteristics of cells were evaluated. OA was induced surgically by anterior cruciate ligament transection (ACLT) and medical meniscectomy of knee joints. At six weeks following surgery, hyaluronic acid (HA) or haMPCs was injected into the knee joints, the contralateral knee served as normal control. All animals were sacrificed at the 16th week post-surgery. Assessments were carried out by macroscopic examination, hematoxylin/eosin (HE) and Safranin-O/Fast green stainings and immunohistochemistry. The data showed that haMPC treatment promoted cartilage repair. Signals of human mitochondrial can be directly detected in haMPC treated cartilage. The haMPCs expressed human leukocyte antigen I (HLA-I) but not HLA-II-DR in vivo. These results suggest that intra-articular injection of haMPCs promotes regeneration of articular cartilage in rabbit OA model, and support the notion that MPCs are transplantable between HLA-incompatible individuals. PMID:26023716

  10. Comparative metabolism of 14C-labeled apixaban in mice, rats, rabbits, dogs, and humans.

    PubMed

    Zhang, Donglu; He, Kan; Raghavan, Nirmala; Wang, Lifei; Mitroka, James; Maxwell, Brad D; Knabb, Robert M; Frost, Charles; Schuster, Alan; Hao, Feng; Gu, Zheming; Humphreys, W Griffith; Grossman, Scott J

    2009-08-01

    The metabolism and disposition of [(14)C]apixaban, a potent, reversible, and direct inhibitor of coagulation factor Xa, were investigated in mice, rats, rabbits, dogs, and humans after a single oral administration and in incubations with hepatocytes. In plasma, the parent compound was the major circulating component in mice, rats, dogs, and humans. O-Demethyl apixaban sulfate (M1) represented approximately 25% of the parent area under the time curve in human plasma. This sulfate metabolite was present, but in lower amounts relative to the parent, in plasma from mice, rats, and dogs. Rabbits showed a plasma metabolite profile distinct from that of other species with apixaban as a minor component and M2 (O-demethyl apixaban) and M14 (O-demethyl apixaban glucuronide) as prominent components. The fecal route was a major elimination pathway, accounting for >54% of the dose in animals and >46% in humans. The urinary route accounted for <15% of the dose in animals and 25 to 28% in humans. Apixaban was the major component in feces of every species and in urine of all species except rabbit. M1 and M2 were common prominent metabolites in urine and feces of all species as well as in bile of rats and humans. In vivo metabolite profiles showed quantitative differences between species and from in vitro metabolite profiles, but all human metabolites were found in animal species. After intravenous administration of [(14)C]apixaban to bile duct-cannulated rats, the significant portion (approximately 22%) of the dose was recovered as parent drug in the feces, suggesting direct excretion of the drug from gastrointestinal tracts of rats. Overall, apixaban was effectively eliminated via multiple elimination pathways in animals and humans, including oxidative metabolism, and direct renal and intestinal excretion. PMID:19420130

  11. Creation of chimeric human/rabbit APOBEC1 with HIV-1 restriction and DNA mutation activities

    NASA Astrophysics Data System (ADS)

    Ikeda, Terumasa; Ong, Eugene Boon Beng; Watanabe, Nobumoto; Sakaguchi, Nobuo; Maeda, Kazuhiko; Koito, Atsushi

    2016-01-01

    APOBEC1 (A1) proteins from lagomorphs and rodents have deaminase-dependent restriction activity against HIV-1, whereas human A1 exerts a negligible effect. To investigate these differences in the restriction of HIV-1 by A1 proteins, a series of chimeric proteins combining rabbit and human A1s was constructed. Homology models of the A1s indicated that their activities derive from functional domains that likely act in tandem through a dimeric interface. The C-terminal region containing the leucine-rich motif and the dimerization domains of rabbit A1 is important for its anti-HIV-1 activity. The A1 chimeras with strong anti-HIV-1 activity were incorporated into virions more efficiently than those without anti-HIV-1 activity, and exhibited potent DNA-mutator activity. Therefore, the C-terminal region of rabbit A1 is involved in both its packaging into the HIV-1 virion and its deamination activity against both viral cDNA and genomic RNA. This study identifies the novel molecular mechanism underlying the target specificity of A1.

  12. Creation of chimeric human/rabbit APOBEC1 with HIV-1 restriction and DNA mutation activities.

    PubMed

    Ikeda, Terumasa; Ong, Eugene Boon Beng; Watanabe, Nobumoto; Sakaguchi, Nobuo; Maeda, Kazuhiko; Koito, Atsushi

    2016-01-01

    APOBEC1 (A1) proteins from lagomorphs and rodents have deaminase-dependent restriction activity against HIV-1, whereas human A1 exerts a negligible effect. To investigate these differences in the restriction of HIV-1 by A1 proteins, a series of chimeric proteins combining rabbit and human A1s was constructed. Homology models of the A1s indicated that their activities derive from functional domains that likely act in tandem through a dimeric interface. The C-terminal region containing the leucine-rich motif and the dimerization domains of rabbit A1 is important for its anti-HIV-1 activity. The A1 chimeras with strong anti-HIV-1 activity were incorporated into virions more efficiently than those without anti-HIV-1 activity, and exhibited potent DNA-mutator activity. Therefore, the C-terminal region of rabbit A1 is involved in both its packaging into the HIV-1 virion and its deamination activity against both viral cDNA and genomic RNA. This study identifies the novel molecular mechanism underlying the target specificity of A1. PMID:26738439

  13. Creation of chimeric human/rabbit APOBEC1 with HIV-1 restriction and DNA mutation activities

    PubMed Central

    Ikeda, Terumasa; Ong, Eugene Boon Beng; Watanabe, Nobumoto; Sakaguchi, Nobuo; Maeda, Kazuhiko; Koito, Atsushi

    2016-01-01

    APOBEC1 (A1) proteins from lagomorphs and rodents have deaminase-dependent restriction activity against HIV-1, whereas human A1 exerts a negligible effect. To investigate these differences in the restriction of HIV-1 by A1 proteins, a series of chimeric proteins combining rabbit and human A1s was constructed. Homology models of the A1s indicated that their activities derive from functional domains that likely act in tandem through a dimeric interface. The C-terminal region containing the leucine-rich motif and the dimerization domains of rabbit A1 is important for its anti-HIV-1 activity. The A1 chimeras with strong anti-HIV-1 activity were incorporated into virions more efficiently than those without anti-HIV-1 activity, and exhibited potent DNA-mutator activity. Therefore, the C-terminal region of rabbit A1 is involved in both its packaging into the HIV-1 virion and its deamination activity against both viral cDNA and genomic RNA. This study identifies the novel molecular mechanism underlying the target specificity of A1. PMID:26738439

  14. Oxytocin mediates the estrogen-dependent contractile activity of endothelin-1 in human and rabbit epididymis.

    PubMed

    Filippi, Sandra; Morelli, Annamaria; Vignozzi, Linda; Vannelli, Gabriella Barbara; Marini, Mirca; Ferruzzi, Pietro; Mancina, Rosa; Crescioli, Clara; Mondaini, Nicola; Forti, Gianni; Ledda, Fabrizio; Maggi, Mario

    2005-08-01

    Epididymis is a sex steroid (androgen + estrogen)-sensitive duct provided with spontaneous motility, allowing sperm transport. We previously reported that the oxytocin (OT) receptor (OTR) mediates an estrogen-dependent increase in epididymal contractility. Because endothelin (ET)-1 also regulates epididymal motility, we tested its sex steroid dependence in a rabbit model. We demonstrated that estrogens up-regulate responsiveness to ET-1, which is reduced by blocking aromatase activity (letrozole, 2.5 mg/kg) or by triptorelin (2.9 mg/kg)-induced hypogonadism, whereas it is fully restored by estradiol valerate (3.3 mg/kg weekly) but not by testosterone enanthate (30 mg/kg weekly). However, changing sex steroid milieu did not affect either ET-1, its receptor gene, or protein expression. Two structurally distinct OTR-antagonists [(d(CH2)5(1), Tyr(Me)(2), Orn(8))-OT and atosiban] almost completely abolished ET-1 contractility, without competing for [125I]ET-1 binding, suggesting that OT/OTR partially mediates ET-1 action. Immunohistochemical studies in human and rabbit epididymis demonstrated that both OT and its synthesis-associated protein, neurophysin I, are expressed in the epithelial cells facing the muscular layer, suggesting local OT production. Quantitative RT-PCR demonstrated a high abundance of OT transcripts in human epididymis. OT transcript was also originally detected and partially sequenced in rabbit epididymis. To verify whether ET-1 regulates OT release, we used rabbit epididymal epithelial cell cultures. These cells expressed a high density of [125I]ET-1 binding sites and responded to ET-1 with a dose-dependent OT release. Hence, we propose that an ET-1-induced OT/OTR system activation underlies the estrogen-dependent hyperresponsiveness to ET-1. These local sources might promote the spontaneous motility necessary for sperm transport. PMID:15860558

  15. Characteristics of rabbit transgenic mammary gland expressing recombinant human factor VIII.

    PubMed

    Chrenek, P; Makarevich, A V; Pivko, J; Massanyi, P; Lukac, N

    2009-02-01

    The objective of this research was to compare (i) the content of milk protein and recombinant human factor VIII (rhFVIII) in the milk of transgenic and non-transgenic rabbit females at three lactations and (ii) histological structure, ultrastructural morphology and occurrence of apoptosis in rabbit transgenic and non-transgenic mammary gland during third lactation and involution. Significant differences (t(0.05)) in milk protein content were found between transgenic and non-transgenic at all three lactations. The percentage of apoptotic cells was significantly higher (t(0.01)) in non-transgenic ones compared with transgenic mammary gland tissues (6.5% versus 2.4%) taken at the involution stage. Morphometrical analysis of histological preparations at the involution stage detected a significantly higher (t(0.05)) relative volume of lumen in transgenic animals compared with non-transgenic ones (60.00 versus 46.51%). Ultrastructural morphology of the transgenic mammary gland epithelium at the involution stage revealed an increased relative volume of protein globules (t(0.05)); at the lactation stage, a significantly higher volume of mitochondria (13.8%) compared with the non-transgenic (9.8%) ones was observed. These results, although revealing differences in some parameters of ultrastructure and histology, indicate no harmful effect of the mouse whey acid protein-hFVIII transgene expression on the state of mammary gland of transgenic rabbit females. PMID:19143684

  16. A rabbit model of human familial, nonsyndromic unicoronal suture synostosis. I. Synostotic onset, pathology, and sutural growth patterns.

    PubMed

    Mooney, M P; Siegel, M I; Burrows, A M; Smith, T D; Losken, H W; Dechant, J; Cooper, G; Kapucu, M R

    1998-06-01

    Poswillo has stated, "The more severe anomalies of the calvaria, such as plagiocephaly, Crouzon [syndrome], and Apert syndrome still defy explanation, in the absence of an appropriate animal system to study" (p. 207). This two-part study reviews data from a recently developed colony of New Zealand white rabbits with familial, nonsyndromic unilateral coronal suture synostosis. Part 1 presents pathological findings and compensatory sutural growth data from 109 normal rabbits and 82 craniosynostotic rabbits from this colony. Synostotic foci, onset, and progression were described in the calvariae from 102 staged (fetal days 21, 25, 27, 33; term = 30 days) fetuses (39 normal, 63 synostosed). Calvarial suture growth patterns from 10 to 126 days of age were assessed from serial radiographs obtained from 89 rabbits (70 normal rabbits and 19 rabbits with unicoronal suture synostosis) with amalgam bone marker implants. Perinatal results revealed that by fetal day 25 the synostotic focal point in synostotic rabbits consistently originated from the endocortical surface of the calvaria in the middle of the coronal suture at a presumed high-tension, interdigitating zone. Histological analysis revealed hyperostotic osteogenic fronts on the affected side compared with the unaffected side. Postnatal sutural growth data revealed a predictable pattern of plagiocephaly (contralateral coronal sutures growing more than ipsilateral sutures and ipsilateral frontonasal and anterior lambdoidal sutures growing more than contralateral sutures), which resulted in early cranial vault deformities and a double "S" shape torquing towards the affected side. The advantages and disadvantages of these rabbits as a model for human familial, nonsyndromic unicoronal suture synostosis are discussed, especially in light of recent cytokine and genetic findings from human craniosynostotic studies. PMID:9694335

  17. Binding of rabbit muscle aldolase to band 3, the predominant polypeptide of the human erythrocyte membrane.

    PubMed

    Strapazon, E; Steck, T L

    1976-04-01

    Aldolase is a trace protein in isolated human red cell membrane preparations. Following total elution of the endogenous enzyme by a saline wash, the interaction of this membrane with rabbit muscle aldolase was studied. At saturation, exogenous aldolase constituted over 40% of the repleted membrane protein. Scatchard analysis revealed two classes of sites, each numbering approximately 7 X 10(5) per ghost. Specificity was suggested by the exclusive binding of the enzyme to the membrane's inner (cytoplasmic) surface. Furthermore, milimolar levels of fructose 1,6-bisphosphate eluted the enzyme from ghosts, while fructose 6-phosphate and NADH (a metabolite which elutes human erythrocyte glyceraldehyde-3-phosphate dehydrogenase (G3PD) from its binding site) were ineffectuve. Removing peripheral membrane proteins with EDTA and lithium 3,5-diiodosalicylate did not diminish the binding capacity of the membranes. An aldolase-band 3 complex, dissociable by high ionic strength or fructose 1,6-bisphosphate treatment, was demonstrated in Triton X-100 extracts of repleted membranes by rate zonal sedimentation analysis on sucrose gradients. We conclude that the association of rabbit muscle aldolase with isolated human erythrocyte membranes reflects its specific binding to band 3 at the cytoplasmic surface, as is also true of G3PD. PMID:1259946

  18. Efficacy of Anti-VEGF and Laser Photocoagulation in the Treatment of Visual Impairment due to Diabetic Macular Edema: A Systematic Review and Network Meta-Analysis

    PubMed Central

    Régnier, Stephane; Malcolm, William; Allen, Felicity; Wright, Jonathan; Bezlyak, Vladimir

    2014-01-01

    aflibercept and both anti-VEGF therapies had statistically superior efficacy to laser. PMID:25029255

  19. Sclera-Choroid-RPE Transport of Eight β-Blockers in Human, Bovine, Porcine, Rabbit, and Rat Models

    PubMed Central

    Kadam, Rajendra S.; Cheruvu, Narayan P. S.; Edelhauser, Henry F.

    2011-01-01

    Purpose. To determine the influence of drug lipophilicity, ocular pigmentation, and species differences on transscleral solute transport. Methods. The transport of eight β-blockers across excised sclera/sclera-choroid-RPE (SCRPE) of albino rabbit, pigmented rabbit, human, porcine, and bovine eyes was determined over 6 hours. The ex vivo transscleral β-blocker transport to the vitreous at the end of 6 hours was determined in euthanatized, pigmented Brown Norway rats. The thicknesses of the sclera and SCRPE and the melanin content in choroid-RPE (CRPE) were measured to determine whether species differences in drug transport can be explained on this basis. Results. Solute lipophilicity inversely correlated with the SCRPE cumulative percentage of transport in all species (R2 ≥ 0.80). The CRPE impeded the SCRPE transport of all β-blockers (51%–64% resistance in the rabbits; 84%–99.8% in the bovine and porcine eyes) more than the sclera, with the impedance increasing with lipophilicity. SCRPE transport followed the trend albino rabbit > pigmented rabbit > human > porcine > bovine, and a cross-species comparison showed good Spearman's rho correlation (R2 ≥ 0.85). Bovine (R2 = 0.84), porcine (R2 = 0.84), and human (R2 = 0.71) SCRPE transport was more predictive than that in the rabbit models (R2 = 0.60–0.61) of transscleral solute transport to the vitreous in rats. The CRPE concentrations were higher in pigmented rabbits than in albino rabbits. The melanin content of the CRPE exhibited the trend albino rabbit ≪ pigmented rabbit < porcine ∼ bovine < rat. Normalization to scleral thickness abolished the species differences in scleral transport. Normalization to SCRPE thickness and melanin content significantly reduced species differences in SCRPE transport. Conclusions. Owing to the presence of pigment and drug binding, choroid-RPE is the principal barrier to transscleral β-blocker transport, with the barrier being more significant for lipophilic

  20. Data on cell growth inhibition induced by anti-VEGF siRNA delivered by Stealth liposomes incorporating G2 PAMAM-cholesterol versus Metafectene® as a function of exposure time and siRNA concentration.

    PubMed

    Golkar, Nasim; Samani, Soliman Mohammadi; Tamaddon, Ali Mohammad

    2016-09-01

    In this data article, carboxyfluorescein-loaded liposomes were prepared and purified from free carboxyfluorescein using gel filtration chromatography in the first part. In the next part, following preparation of anti-VEGF siRNA loaded liposomes incorporating hydrophobically modified G2 PAMAM dendrimer (G2-Chol40%) (Golkar et al., 2016) [1], the cell growth inhibition induced by the formulations (siRNA/Metafectene complexes and siRNA loaded liposomes incorporating hydrophobic G2) was evaluated at two exposure times through MTT assay in a breast cancer cell (SKBR-3) and compared by two-way ANOVA. PMID:27508257

  1. Oxytocin does not directly alter cardiac repolarization in rabbit or human cardiac myocytes.

    PubMed

    Qu, Yusheng; Fang, Mei; Gao, BaoXi; Amagasu, Shanti; Crumb, William J; Vargas, Hugo M

    2015-02-01

    Oxytocin, a nine amino acid peptide, is highly conserved in placental mammals, including humans. Oxytocin has a physiological role in parturition and parenteral administration of the synthetic peptide is used to induce labor and control postpartum hemorrhage. Endogenous levels of oxytocin before labor are ∼20 pg/mL, but pharmacological administration of the peptide can achieve levels of 110 pg/mL (0.1 nmol/L) following intravenous administration. Cardiac arrhythmia and premature ventricular contractions have been associated with oxytocin administration in addition to QTc interval prolongation. In the conscious rabbit model, intravenous oxytocin produced QT and QTc prolongation. The mechanism of oxytocin-induced QTc prolongation is uncertain but could be the result of indirect changes in autonomic nervous tone, or a direct effect on the duration of cardiomyocyte repolarization. The purpose of this study was to examine the ability of oxytocin to alter cardiac repolarization directly. Two conventional models were used: QTc interval evaluation in the isolated rabbit heart (IRH) and assessment of action potential duration (APD) in human ventricular myocytes (HVM). Oxytocin did not prolong QTc intervals in IRH or APD in HVM when tested at suprapharmacological concentrations, for example, up to 1 μmol/L. The results indicate that oxytocin has very low risk for eliciting QTc and APD prolongation directly, and infer that the QTc changes observed in vivo may be attributed to an indirect mechanism. PMID:25692020

  2. Oxytocin does not directly alter cardiac repolarization in rabbit or human cardiac myocytes

    PubMed Central

    Qu, Yusheng; Fang, Mei; Gao, BaoXi; Amagasu, Shanti; Crumb, William J; Vargas, Hugo M

    2015-01-01

    Oxytocin, a nine amino acid peptide, is highly conserved in placental mammals, including humans. Oxytocin has a physiological role in parturition and parenteral administration of the synthetic peptide is used to induce labor and control postpartum hemorrhage. Endogenous levels of oxytocin before labor are ∼20 pg/mL, but pharmacological administration of the peptide can achieve levels of 110 pg/mL (0.1 nmol/L) following intravenous administration. Cardiac arrhythmia and premature ventricular contractions have been associated with oxytocin administration in addition to QTc interval prolongation. In the conscious rabbit model, intravenous oxytocin produced QT and QTc prolongation. The mechanism of oxytocin-induced QTc prolongation is uncertain but could be the result of indirect changes in autonomic nervous tone, or a direct effect on the duration of cardiomyocyte repolarization. The purpose of this study was to examine the ability of oxytocin to alter cardiac repolarization directly. Two conventional models were used: QTc interval evaluation in the isolated rabbit heart (IRH) and assessment of action potential duration (APD) in human ventricular myocytes (HVM). Oxytocin did not prolong QTc intervals in IRH or APD in HVM when tested at suprapharmacological concentrations, for example, up to 1 μmol/L. The results indicate that oxytocin has very low risk for eliciting QTc and APD prolongation directly, and infer that the QTc changes observed in vivo may be attributed to an indirect mechanism. PMID:25692020

  3. Human Umbilical Cord Blood Cells Ameliorates Motor Deficits In Rabbits In a Cerebral Palsy Model

    PubMed Central

    Drobyshevsky, A.; Cotten, C. M.; Shi, Z.; Luo, K.; Jiang, R.; Derrick, M.; Tracy, E. T.; Gentry, T.; Goldberg, R. N.; Kurtzberg, J.; Tan, S.

    2015-01-01

    Cerebral palsy (CP) has significant impact on both patients and society but therapy is limited. Human umbilical cord blood cells (HUCBC), containing various stem and progenitor cells, have been used to treat various brain genetic conditions. In small animal experiments, HUCBC have improved outcomes after hypoxic-ischemic injury. Clinical trials using HUCBC are underway testing feasibility, safety and efficacy for neonatal injury as well as CP. We tested HUCBC therapy in a validated rabbit model of CP after acute changes secondary to hypoxic-ischemic (H-I) injury had subsided. Following uterine ischemia at 70% gestation, we infused HUCBC to newborn rabbit kits with either mild or severe neurobehavioral changes. Infusion of high dose HUCBC, 5x106 cells, dramatically altered the natural history of the injury alleviating the abnormal phenotype including posture, righting reflex, locomotion, tone, and dystonia. Half the high dose showed lesser but still significant improvement. The swimming test however showed that joint function did not restore to naïve control function in either group. Tracing HUCBCs with either MRI biomarkers or PCR for human DNA found little penetration of HUCBC in the newborn brain in the immediate newborn period, suggesting that the beneficial effects were not due to cellular integration or direct proliferative effects but rather to paracrine signaling. This is the first study to show that HUCBC improve motor performance in a dose-dependent manner perhaps by improving compensatory repair processes. PMID:25791742

  4. Pneumonic Tularemia in Rabbits Resembles the Human Disease as Illustrated by Radiographic and Hematological Changes after Infection

    PubMed Central

    Reed, Douglas S.; Smith, Le'Kneitah; Dunsmore, Tammy; Trichel, Anita; Ortiz, Luis A.; Cole, Kelly Stefano; Barry, Eileen

    2011-01-01

    Background Pneumonic tularemia is caused by inhalation of the gram negative bacterium, Francisella tularensis. Because of concerns that tularemia could be used as a bioterrorism agent, vaccines and therapeutics are urgently needed. Animal models of pneumonic tularemia with a pathophysiology similar to the human disease are needed to evaluate the efficacy of these potential medical countermeasures. Principal Findings Rabbits exposed to aerosols containing Francisella tularensis strain SCHU S4 developed a rapidly progressive fatal pneumonic disease. Clinical signs became evident on the third day after exposure with development of a fever (>40.5°C) and a sharp decline in both food and water intake. Blood samples collected on day 4 found lymphopenia and a decrease in platelet counts coupled with elevations in erythrocyte sedimentation rate, alanine aminotransferase, cholesterol, granulocytes and monocytes. Radiographs demonstrated the development of pneumonia and abnormalities of intestinal gas consistent with ileus. On average, rabbits were moribund 5.1 days after exposure; no rabbits survived exposure at any dose (190–54,000 cfu). Gross evaluation of tissues taken at necropsy showed evidence of pathology in the lungs, spleen, liver, kidney and intestines. Bacterial counts confirmed bacterial dissemination from the lungs to the liver and spleen. Conclusions/Significance The pathophysiology of pneumonic tularemia in rabbits resembles what has been reported for humans. Rabbits therefore are a relevant model of the human disease caused by type A strains of F. tularensis. PMID:21931798

  5. Hepatitis E Virus in Farmed Rabbits, Wild Rabbits and Petting Farm Rabbits in the Netherlands.

    PubMed

    Burt, Sara A; Veltman, Jorg; Hakze-van der Honing, Renate; Schmitt, Heike; van der Poel, Wim H M

    2016-09-01

    Rabbits have been suggested as a zoonotic source of Hepatitis E virus. Phylogenetic analysis of HEV isolates from farmed, wild and pet rabbits in the Netherlands (23, 0, and 60 % respectively) showed them to be grouped amongst published rabbit HEV sequences and distinct from most human isolates. Dutch rabbits are unlikely to be a zoonotic source. PMID:27147250

  6. Complete Genome Analysis of a Rabbit Rotavirus Causing Gastroenteritis in a Human Infant

    PubMed Central

    Bonica, Melisa Berenice; Zeller, Mark; Van Ranst, Marc; Matthijnssens, Jelle; Heylen, Elisabeth

    2015-01-01

    Group A rotaviruses (RVA) are responsible for causing infantile diarrhea both in humans and animals. The molecular characteristics of lapine RVA strains are only studied to a limited extent and so far G3P[14] and G3P[22] were found to be the most common G/P-genotypes. During the 2012-2013 rotavirus season in Belgium, a G3P[14] RVA strain was isolated from stool collected from a two-year-old boy. We investigated whether RVA/Human-wt/BEL/BE5028/2012/G3P[14] is completely of lapine origin or the result of reassortment event(s). Phylogenetic analyses of all gene segments revealed the following genotype constellation: G3-P[14]-I2-R2-C2-M3-A9-N2-T6-E5-H3 and indicated that BE5028 probably represents a rabbit to human interspecies transmission able to cause disease in a human child. Interestingly, BE5028 showed a close evolutionary relationship to RVA/Human-wt/BEL/B4106/2000/G3P[14], another lapine-like strain isolated in a Belgian child in 2000. The phylogenetic analysis of the NSP3 segment suggests the introduction of a bovine(-like) NSP3 into the lapine RVA population in the past 12 years. Sequence analysis of NSP5 revealed a head-to-tail partial duplication, combined with two short insertions and a deletion, indicative of the continuous circulation of this RVA lineage within the rabbit population. PMID:25690801

  7. Pulmonary effects of inhaled zinc oxide in human subjects, guinea pigs, rats, and rabbits

    SciTech Connect

    Gordon, T.; Chen, L.C.; Fine, J.M.; Schlesinger, R.B.; Su, W.Y.; Kimmel, T.A.; Amdur, M.O. )

    1992-08-01

    Occupational exposure to freshly formed zinc oxide (ZnO) particles (less than 1.0 micron aerodynamic diameter) produces a well-characterized response known as metal fume fever. An 8-hr threshold limit value (TLV) of 5 mg/m3 has been established to prevent adverse health effects because of exposure to ZnO fumes. Because animal toxicity studies have demonstrated pulmonary effects near the current TLV, the present study examined the time course and dose-response of the pulmonary injury produced by inhaled ZnO in guinea pigs, rats, rabbits, and human volunteers. The test animals were exposed to 0, 2.5, or 5.0 mg/m3 ZnO for up to 3 hr and their lungs lavaged. Both the lavage fluid and recovered cells were examined for evidence of inflammation or altered cell function. The lavage fluid from guinea pigs and rats exposed to 5 mg/m3 had significant increases in total cells, lactate dehydrogenase, beta-glucuronidase, and protein content. These changes were greatest 24 hr after exposure. Guinea pig alveolar macrophage function was depressed as evidenced by in vitro phagocytosis of opsonized latex beads. Significant changes in lavage fluid parameters were also observed in guinea pigs and rats exposed to 2.5 mg/m3 ZnO. In contrast, rabbits showed no increase in biochemical or cellular parameters following a 2-hr exposure to 5 mg/m3 ZnO. Differences in total lung burden of ZnO, as determined in additional animals by atomic absorption spectroscopy, appeared to account for the observed differences in species responses. Although the lungs of guinea pigs and rats retained approximately 20% and 12% of the inhaled dose, respectively, rabbits retained only 5%.

  8. Nuclear imaging analysis of human low-density lipoprotein biodistribution in rabbits and monkeys

    SciTech Connect

    Hay, R.V.; Fleming, R.M.; Ryan, J.W.; Williams, K.A.; Stark, V.J.; Lathrop, K.A.; Harper, P.V. )

    1991-06-01

    We have evaluated the biodistribution of human low-density lipoprotein (LDL) radiolabeled with 99mTc or with {sup 123}I-tyramine cellobiose in rabbits and in rhesus monkeys. Biodistribution was assessed after intravenous injection of radiolabeled LDL by quantitative analysis of scintigrams, counting of excreta, and counting of tissues at necropsy. Both rabbits and monkeys showed lower renal uptake ({sup 123}I:99mTc {approximately} 1:3, as regional percent injected activity corrected for physical decay) and excretion (1:2 to 1:4), but higher hepatic (1.5:1 to 2:1) and cardiac (1.7:1 to 4:1) uptake of {sup 123}I than of 99mTc. Adrenals were visualized in normolipemic animals with {sup 123}I-tyramine cellobiose-LDL but not with 99mTc-LDL. Hyperlipemic animals showed increased cardiac (up to six-fold) and decreased hepatic activity (by 50%-60%) of both radionuclides. We conclude that {sup 123}I-tyramine cellobiose-LDL is better suited than 99mTc-LDL for dynamic studies of LDL metabolism in vivo.

  9. Association of the polymorphism Y402H in the CFH gene with response to anti-VEGF treatment in age-related macular degeneration: a systematic review and meta-analysis.

    PubMed

    Hong, Nan; Shen, Ye; Yu, Chen-Ying; Wang, Shu-Qun; Tong, Jian-Ping

    2016-06-01

    To explore whether the complement factor H (CFH) polymorphism rs1061170/Y402H is associated with responsiveness to antivascular endothelial growth factor (VEGF) agents in age-related macular degeneration (AMD). We reviewed the English literature to examine the association between the polymorphism rs1061170/Y402H of the CFH gene and responsiveness to treatment with anti-VEGF drugs in AMD patients. A meta-analysis of eligible studies was also performed. Pooled odds ratios (ORs) and 95% CIs were estimated using Stata V.12.0. Statistical heterogeneity was measured using Q-statistic testing. Fourteen relevant studies including a total of 2963 AMD patients were eligible. In AMD patients without a treatment history, individuals carrying the rs1061170/Y402H TT genotype were more likely to achieve a better outcome (OR = 1.932, 95% CI = 1.125-3.317, p = 0.017) than those carrying the CC genotype. The polymorphism rs1061170/Y402H might be a genetic predictor of treatment response to anti-VEGF therapy in AMD patients. Further prospective research including a larger number of patients is needed to validate this finding. PMID:27151934

  10. Myxoma virus expressing human interleukin-12 does not induce myxomatosis in European rabbits.

    PubMed

    Stanford, Marianne M; Barrett, John W; Gilbert, Philippe-Alexandre; Bankert, Richard; McFadden, Grant

    2007-11-01

    Myxoma virus (MV) is a candidate for oncolytic virotherapy due to its ability to selectively infect and kill tumor cells, yet MV is a species-specific pathogen that causes disease only in European rabbits. To assess the ability of MV to deliver cytokines to tumors, we created an MV (vMyxIL-12) that expresses human interleukin-12 (IL-12). vMyxIL-12 replicates similarly to wild-type MV, and virus-infected cells secrete bioactive IL-12. Yet, vMyxIL-12 does not cause myxomatosis, despite expressing the complete repertoire of MV proteins. Thus, vMyxIL-12 exhibits promise as an oncolytic candidate and is safe in all known vertebrate hosts, including lagomorphs. PMID:17728229

  11. Purification of rabbit kidney cytokinase and a comparison of its properties with human urokinase

    PubMed Central

    Ali, S. Y.; Evans, Lois

    1968-01-01

    1. The cytokinase (tissue activator of plasminogen) content of several mammalian tissues was evaluated by a quantitative casein hydrolysis method. 2. An alkaline (pH10·5) extraction of cytokinase from rabbit kidney lysosome–microsome fraction, followed by chromatography on DEAE-cellulose at pH7·6 with stepwise or linear increase in concentration of phosphate buffer, gave an 86-fold purification of the enzyme. The purified material was non-proteolytic against casein and heated fibrin and was freeze-dried without significant loss of activity or solubility. 3. Cytokinase is a protein with E0·1%1cm.=0·87 at 280mμ, and does not possess sufficient hexose or sialic acid to be classified as a glycoprotein. It has S20,w 2·9–3·1s and molecular weight 50000 when measured on a calibrated Sephadex G-100 column. It has an isoelectric point between pH8 and pH9, and is maximally active and stable at pH8·5. It is inactivated by heat at 78°. 4. Cytokinase and human urokinase have the same Km value and are inhibited in a partially competitive manner by ∈-aminohexanoic acid and aminomethylcyclohexanecarboxylic acid. They are also inhibited by cysteine and arginine, but are unaffected by iodoacetamide and p-chloromercuribenzoate. 5. On the basis of this and other evidence it is suggested that rabbit kidney cytokinase and human urokinase are similar, if not identical, enzymes. PMID:5641883

  12. N-/O-glycosylation analysis of human FVIIa produced in the milk of transgenic rabbits

    PubMed Central

    Chevreux, Guillaume; Faid, Valegh; Scohyers, Jean-Marc; Bihoreau, Nicolas

    2013-01-01

    Human coagulation factor VIIa is a glycoprotein that promotes haemostasis through activation of the coagulation cascade extrinsic pathway. Most haemophilia A/B patients with inhibitors are treated by injection of plasma-derived or recombinant FVIIa. The use of recombinant products raises questions about the ability of the host cell to produce efficiently post-translationally modified proteins. Glycosylation is especially critical considering that it can modulate protein safety and efficacy. The present paper reports the N-/O-glycosylation pattern of a new recombinant human factor VIIa expressed in the mammary glands of transgenic rabbits. Glycosylation was investigated by chromatography and advanced mass spectrometry techniques for glycan identification and quantitation. Mass spectrometry (MS)/MS analyses were performed to confirm the glycan structures as well as the position and branching of specific monosaccharides or substituents. The two N-glycosylation sites were found to be fully occupied mostly by mono- and bi-sialylated biantennary complex-type structures, the major form being A2G2S1. Some oligomannose/hybrid structures were retrieved in lower abundance, the major ones being GlcNAcα1,O-phosphorylated at the C6-position of a Man residue (Man-6-(GlcNAcα1,O-)phosphate motif) as commonly observed on lysosomal proteins. No immunogenic glycotopes such as Galili (Galα1,3Gal) and HD antigens (N-glycolylneuraminic acid (NeuGc)) were detected. Concerning O-glycosylation, the product exhibited O-fucose and O-glucose-(xylose)0, 1, 2 motifs as expected. The N-glycosylation consistency was also investigated by varying production parameters such as the period of lactation, the number of consecutive lactations and rabbit generations. Results show that the transgenesis technology is suitable for the long-term production of rhFVIIa with a reproducible glycosylation pattern. PMID:24092837

  13. Culicidae (Diptera) selection of humans, chickens and rabbits in three different environments in the province of Chaco, Argentina

    PubMed Central

    Stein, Marina; Zalazar, Laura; Willener, Juana Alicia; Almeida, Francisco Ludueña; Almirón, Walter Ricardo

    2013-01-01

    Studies were conducted to determine the selection of humans, chickens and rabbits by Culicidae in three different environments in the province of Chaco, Argentina. Mosquitoes were collected fortnightly using cylindrical metal traps containing animal bait (chickens and rabbits). The mosquitoes were collected between June 2001-May 2002. During the same period and with the same frequency, mosquitoes biting the human operators of the traps were collected during the first 15 min of exposure within different time intervals: from 09:00 am-11:00 am, 01:00 pm-03:00 pm, 05:00 pm-07:00 pm and 09:00 pm-10:00 pm. A total of 19,430 mosquitoes of 49 species belonging to 10 genera were collected. Culex species mainly selected chicken bait and Wyeomyia species selected rabbit bait. Ochlerotatus and Psorophora species were more abundant in rabbit-baited traps. Anopheles triannulatus, Coquillettidia nigricans, Ochlerotatus scapularis, Mansonia titillans and Psorophora albigenu showed a strong attraction for human bait. The Anopheles, Coquillettidia, Culex and Mansonia species were more active between 05:00 pm-09:00 pm, while Ochlerotatus, Psorophora, Haemagogus and Wyeomyia were most active from 09:00 am-07:00 pm. This study provides additional information about the biology and ecology of arbovirus vectors in Chaco. PMID:23903970

  14. Stereoselective pharmacokinetics and metabolism of the enantiomers of cyclophosphamide. Preliminary results in humans and rabbits.

    PubMed

    Holm, K A; Kindberg, C G; Stobaugh, J F; Slavik, M; Riley, C M

    1990-04-15

    [R(+),S(-)]-Cyclophosphamide [(R,S)-CP] is an anticancer drug, containing a chiral phosphorous atom, which is prepared and used clinically as the racemic mixture. A new high-performance liquid chromatographic assay suitable for pharmacokinetic studies of CP enantiomers in plasma has been reported recently by this laboratory (Reid et al., Anal Chem 61: 441-446, 1989). Briefly, the assay involves ethyl acetate extraction of CP enantiomers from plasma followed by derivatization to diastereomers in a two-step process utilizing chloral and (+)-naproxen acid chloride. Chromatographic analysis was performed on a reversed phase (ODS) column with detection at 232 nm. In the present study, preliminary results on the applicability of this assay to pharmacokinetic studies are presented. Several rabbits were used to compare the influence of i.p., i.v., and oral routes of administration on the stereoselective disposition of (R,S)-CP. Following i.p. administration, S-CP was cleared faster than R-CP. Following oral administration, only R-CP was detectable in plasma, while i.v. administration resulted in minor or no stereoselective disposition. These results indicated that there was a marked stereoselective metabolism of the S-CP enantiomer, with the i.p. and oral routes producing the greatest differences due to first-pass metabolism. Incubation of rabbit-liver microsomes with (R,S)-CP demonstrated that the monooxygenase system can exhibit marked stereoselectivity in its metabolism of CP. The ratio of R-CP to S-CP in the incubation medium increased during the incubation period from 1:1 initially to 4.5:1 after 60 min. The results from the experiments with rabbits indicate that the first-pass metabolism of this drug is highly stereoselective; in contrast, cancer patients who had received (R,S)-CP as an i.v. infusion showed no stereoselectivity in the elimination of the enantiomers. Pharmacokinetic studies with cancer patients, receiving (R,S)-CP as an oral dose, are in progress in

  15. Use of human nail for reconstruction of the orbital floor: an experimental study in rabbits.

    PubMed

    Görgülü, Tahsin; Akçal, Arzu; Uğurlu, Kemal

    2016-07-01

    The orbital floor is the thinnest part of the orbital wall, and in 20% of all maxillofacial injuries it is fractured. Autografts, allografts, and alloplastic materials are used in reconstruction, but there is no consensus about which material is the most appropriate. Nail is a semirigid material that is easy to reshape and is not antigenic. Alloplastic materials, which are used in reconstructions of the orbital floor, have various complications and are expensive. Autografts have donor-site problems, high rates of resorption, and take a long time to do. We created bilateral 10mm defects in the orbital floors in 18 New Zealand rabbits. We reconstructed the left orbital floors with double-ground human nail while the right orbital floors were left open as controls. The orbital floors were examined macroscopically and microscopically at 4, 8, and 12 weeks postoperatively, and there were no macroscopic signs of infection, inflammation, or extrusion. Forced duction tests showed that it was possible to induce movement of the eyeball for all 18 of the reconstructed sides throughout the observation period, and in 14 of the 18 rabbits on the control sides. Positive forced duction test shows us that orbital muscles are trapped in orbital floor defect and due to this movement of eyeball is restricted. Acute and chronic inflammation, fibrosis, vascularisation, and the presence of foreign body giant cells were evaluated microscopically. Acute inflammation and the presence of foreign body giant cells were recorded as mild, whereas fibrosis, chronic inflammation, and vascularisation were severe, as were epithelialisation on the maxillary sinus side of the nails, calcification, and progression of collagen. We found no signs of resorption of the nails. PMID:27090026

  16. Demineralized dentin matrix combined with recombinant human bone morphogenetic protein-2 in rabbit calvarial defects

    PubMed Central

    2016-01-01

    Objectives The aim of this study was to compare the osteogenic effects of demineralized dentin matrix (DDM) combined with recombinant human bone morphogenetic protein-2 (rhBMP-2) in rabbit calvarial defects with DDM and anorganic bovine bone (ABB) combined with rhBMP-2. Materials and Methods Four round defects with 8-mm diameters were created in each rabbit calvaria. Each defect was treated with one of the following: 1) DDM, 2) ABB/rhBMP-2, or 3) DDM/rhBMP-2. The rhBMP-2 was combined with DDM and ABB according to a stepwise dry and dip lyophilizing protocol. Histological and microcomputed tomography (µCT) analyses were performed to measure the amount of bone formation and bone volume after 2- and 8-week healing intervals. Results Upon histological observation at two weeks, the DDM and ABB/rhBMP-2 groups showed osteoconductive bone formation, while the DDM/rhBMP-2 group showed osteoconductive and osteoinductive bone formation. New bone formation was higher in DDM/rhBMP-2, DDM and ABB decreasing order. The amounts of bone formation were very similar at two weeks; however, at eight weeks, the DDM/rhBMP-2 group showed a two-fold greater amount of bone formation compared to the DDM and ABB/rhBMP-2 groups. The µCT analysis showed markedly increased bone volume in the DDM/rhBMP-2 group at eight weeks compared with that of the DDM group. Notably, there was a slight decrease in bone volume in the ABB/rhBMP-2 group at eight weeks. There were no significant differences among the DDM, ABB/rhBMP-2, and DDM/rhBMP-2 groups at two or eight weeks. Conclusion Within the limitations of this study, DDM appears to be a suitable carrier for rhBMP-2 in orthotopic sites. PMID:27162749

  17. Rabbit antithymocyte globulin–induced serum sickness disease and human kidney graft survival

    PubMed Central

    Couvrat-Desvergnes, Grégoire; Salama, Apolline; Le Berre, Ludmilla; Evanno, Gwénaëlle; Viklicky, Ondrej; Hruba, Petra; Vesely, Pavel; Guerif, Pierrick; Dejoie, Thomas; Rousse, Juliette; Nicot, Arnaud; Bach, Jean-Marie; Ang, Evelyn; Foucher, Yohann; Brouard, Sophie; Castagnet, Stéphanie; Giral, Magali; Harb, Jean; Perreault, Hélène; Charreau, Béatrice; Lorent, Marine; Soulillou, Jean-Paul

    2015-01-01

    BACKGROUND. Rabbit-generated antithymocyte globulins (ATGs), which target human T cells, are widely used as immunosuppressive agents during treatment of kidney allograft recipients. However, ATGs can induce immune complex diseases, including serum sickness disease (SSD). Rabbit and human IgGs have various antigenic differences, including expression of the sialic acid Neu5Gc and α-1-3-Gal (Gal), which are not synthesized by human beings. Moreover, anti-Neu5Gc antibodies have been shown to preexist and be elicited by immunization in human subjects. This study aimed to assess the effect of SSD on long-term kidney allograft outcome and to compare the immunization status of grafted patients presenting with SSD following ATG induction treatment. METHODS. We analyzed data from a cohort of 889 first kidney graft recipients with ATG induction (86 with SSD [SSD+] and 803 without SSD [SSD–]) from the Données Informatisées et Validées en Transplantation data bank. Two subgroups of SSD+ and SSD– patients that had received ATG induction treatment were then assessed for total anti-ATG, anti-Neu5Gc, and anti-Gal antibodies using ELISA assays on sera before and after transplantation. RESULTS. SSD was significantly associated with long-term graft loss (>10 years, P = 0.02). Moreover, SSD+ patients exhibited significantly elevated titers of anti-ATG (P = 0.043) and anti-Neu5Gc (P = 0.007) IgGs in late post-graft samples compared with SSD– recipients. CONCLUSION. In conclusion, our data indicate that SSD is a major contributing factor of late graft loss following ATG induction and that anti-Neu5Gc antibodies increase over time in SSD+ patients. FUNDING. This study was funded by Société d’Accélération du Transfert de Technologies Ouest Valorisation, the European FP7 “Translink” research program, the French National Agency of Research, Labex Transplantex, the Natural Science and Engineering Research Council of Canada, and the Canadian Foundation for Innovation. PMID

  18. Highly sensitive label free electrochemical detection of VGEF165 tumor marker based on "signal off" and "signal on" strategies using an anti-VEGF165 aptamer immobilized BSA-gold nanoclusters/ionic liquid/glassy carbon electrode.

    PubMed

    Shamsipur, Mojtaba; Farzin, Leila; Amouzadeh Tabrizi, Mahmoud; Molaabasi, Fatemeh

    2015-12-15

    In this work, a label free electrochemical aptasensor for the detection of ultra-traces of vascular endothelial growth factor (VEGF165) based on "signal off" and "signal on" mechanisms of response was developed. The BSA-gold nanoclusters/ionic liquid (BSA-AuNCs/IL) was used as a suitable nanocomposite platform for immobilization of the aptamer on a glassy carbon electrode. In "signal off" mechanism, the interaction of VEGF165 with its anti-VEGF165 aptamers, resulted in desorption of methylene blue (MB) probe from aptamer and its release into solution. Consequently, the decrease in current intensity of the differential pulse voltammogram of adsorbed MB was monitored and found to be linearly proportional with increasing concentration of VEGF165 in sample solution in the range of 1-120 pM with a limit of detection of 0.32p M. While, in "signal on" mechanism, the interaction of immobilized anti-VEGF165 aptamers on the electrode surface with VEGF165, led to more mass-transfer limiting of the [Fe(CN)6](3-/4-) probe to the electrode surface. Therefore, the charge transfer resistance (Rct) of the probe was increased linearly with increasing concentration of VEGF165 in the range of 2.5-250 pM with a limit of detection of 0.48 pM. The experimental results demonstrated that both of these mechanisms are suitable for determination of low levels of the VEGF165 tumor marker in serum samples. PMID:26162327

  19. Detection thresholds for amplitude modulations of tones in budgerigar, rabbit, and human.

    PubMed

    Carney, Laurel H; Ketterer, Angela D; Abrams, Kristina S; Schwarz, Douglas M; Idrobo, Fabio

    2013-01-01

    Envelope fluctuations of complex sounds carry information that is -essential for many types of discrimination and for detection in noise. To study the neural representation of envelope information and mechanisms for processing of this temporal aspect of sounds, it is useful to identify an animal model that can -sensitively detect amplitude modulations (AM). Low modulation frequencies, which dominate speech sounds, are of particular interest. Yet, most animal -models studied previously are relatively insensitive to AM at low modulation -frequencies. Rabbits have high thresholds for low-frequency modulations, -especially for tone carriers. Rhesus macaques are less sensitive than humans to low-frequency -modulations of wideband noise (O'Conner et al. Hear Res 277, 37-43, 2011). Rats and -chinchilla also have higher thresholds than humans for amplitude -modulations of noise (Kelly et al. J Comp Psychol 120, 98-105, 2006; Henderson et al. J Acoust Soc Am 75, -1177-1183, 1984). In contrast, the budgerigar has thresholds for AM detection of wideband noise similar to those of human listeners at low -modulation frequencies (Dooling and Searcy. Percept Psychophys 46, 65-71, 1981). A -one-interval, two-alternative operant conditioning procedure was used to estimate AM -detection thresholds for 4-kHz tone carriers at low modulation -frequencies (4-256 Hz). Budgerigar thresholds are comparable to those of human subjects in a comparable task. Implications of these comparative results for temporal coding of complex sounds are discussed. Comparative results for masked AM detection are also presented. PMID:23716245

  20. Detection Thresholds for Amplitude Modulations of Tones in Budgerigar, Rabbit, and Human

    PubMed Central

    Ketterer, Angela D.; Abrams, Kristina S.; Schwarz, Douglas M.; Idrobo, Fabio

    2015-01-01

    Envelope fluctuations of complex sounds carry information that is essential for many types of discrimination and for detection in noise. To study the neural representation of envelope information and mechanisms for processing of this temporal aspect of sounds, it is useful to identify an animal model that can sensitively detect amplitude modulations (AM). Low modulation frequencies, which dominate speech sounds, are of particular interest. Yet, most animal models studied previously are relatively insensitive to AM at low modulation frequencies. Rabbits have high thresholds for low-frequency modulations, especially for tone carriers. Rhesus macaques are less sensitive than humans to low-frequency modulations of wideband noise (O’Conner et al. Hear Res 277, 37–43, 2011). Rats and chinchilla also have higher thresholds than humans for amplitude modulations of noise (Kelly et al. J Comp Psychol 120, 98–105, 2006; Henderson et al. J Acoust Soc Am 75, 1177–1183, 1984). In contrast, the budgerigar has thresholds for AM detection of wideband noise similar to those of human listeners at low modulation frequencies (Dooling and Searcy. Percept Psychophys 46, 65–71, 1981). A one-interval, two-alternative operant conditioning procedure was used to estimate AM detection thresholds for 4-kHz tone carriers at low modulation frequencies (4–256 Hz). Budgerigar thresholds are comparable to those of human subjects in a comparable task. Implications of these comparative results for temporal coding of complex sounds are discussed. Comparative results for masked AM detection are also presented. PMID:23716245

  1. Development of the Lacrimal Apparatus in the Rabbit (Oryctolagus cuniculus) and Its Potential Role as an Animal Model for Humans

    PubMed Central

    Rehorek, S. J.; Holland, J. R.; Johnson, J. L.; Caprez, J. M.; Cray, J.; Mooney, M. P.; Hillenius, W. J.; Smith, T. D.

    2011-01-01

    Rabbits have been proposed as a model organism for the human lacrimal apparatus (LA), including the nasolacrimal duct (NLD), based principally on comparative studies of adult morphology; however, little is known about its development. The NLD first appears as an incomplete primordium in the subcutaneous region of the primordial eyelid and subsequently elongates to reach the naris. One posterior and three anterior orbital glands are present fetally although one of the anterior glands is soon lost. The NLD follows a tortuous path and passes through a bony canal consisting of lacrimal, maxilla, and maxilloturbinal bones at different regions. Although early developmental similarities exist to haplorhine primates, the narial opening of the NLD resembles strepsirrhines. This distinction, along with the ductal and glandular differences at the orbital end of the NLD, indicates that rabbits may be a poor model for LA drainage in primates, specifically humans. PMID:22567296

  2. Transmission of Human T-Cell Lymphotropic Virus Type 1 Tax to Rabbits by tax-Only-Positive Human Cells

    PubMed Central

    Zucker-Franklin, Dorothea; Pancake, Bette A.; Lalezari, Parviz; Khorshidi, Manoochehr

    2000-01-01

    The human T-cell lymphrotropic virus type 1 (HTLV-1) is causally related to adult T-cell leukemia and lymphoma and the neurodegenerative diseases tropical spastic paraparesis and HTLV-1-associated myelopathy. In the United States the prevalence of infection has been estimated to range from 0.016 to 0.1% on the basis of serologic tests for antibodies to the viral structural proteins. Blood from donors positive for antibodies to HTLV-1 or HTLV-2 is not used for transfusion. However, patients with the cutaneous T-cell lymphoma mycosis fungoides (MF) are HTLV-1 and -2 seronegative yet harbor proviral sequences identical to those that encode the HTLV-1 transactivating and transforming gene product p40tax in their peripheral blood mononuclear cells (PBMCs), and they usually have antibodies to p40tax. Moreover, a study of 250 randomly selected blood donors revealed that approximately 8% of these seronegative individuals also had HTLV-1 tax sequences and antibodies to p40tax, while they lacked sequences and antibodies related to gag, pol, or env. Thus, it seemed important to determine whether the “tax-only” state can be transmitted by transfusion. To this end, PBMCs from HTLV-1 and -2 seronegative tax-only-positive MF patients or from healthy tax-only-positive blood donors were injected into adult rabbits, an established animal model for HTLV-1 infection. The PBMCs of all injected rabbits became tax sequence positive. These observations suggest that HTLV-1 tax can be transmitted by tax-only-positive mononuclear cells. PMID:10702504

  3. Stretchable, multiplexed pH sensors with demonstrations on rabbit and human hearts undergoing ischemia.

    PubMed

    Chung, Hyun-Joong; Sulkin, Matthew S; Kim, Jong-Seon; Goudeseune, Camille; Chao, Hsin-Yun; Song, Joseph W; Yang, Sang Yoon; Hsu, Yung-Yu; Ghaffari, Roozbeh; Efimov, Igor R; Rogers, John A

    2014-01-01

    Stable pH is an established biomarker of health, relevant to all tissues of the body, including the heart. Clinical monitoring of pH in a practical manner, with high spatiotemporal resolution, is particularly difficult in organs such as the heart due to its soft mechanics, curvilinear geometry, heterogeneous surfaces, and continuous, complex rhythmic motion. The results presented here illustrate that advanced strategies in materials assembly and electrochemical growth can yield interconnected arrays of miniaturized IrOx pH sensors encapsulated in thin, low-modulus elastomers to yield conformal monitoring systems capable of noninvasive measurements on the surface of the beating heart. A thirty channel custom data acquisition system enables spatiotemporal pH mapping with a single potentiostat. In vitro testing reveals super-Nernstian sensitivity with excellent uniformity (69.9 ± 2.2 mV/pH), linear response to temperature (-1.6 mV °C(-1) ), and minimal influence of extracellular ions (<3.5 mV). Device examples include sensor arrays on balloon catheters and on skin-like stretchable membranes. Real-time measurement of pH on the surfaces of explanted rabbit hearts and a donated human heart during protocols of ischemia-reperfusion illustrate some of the capabilities. Envisioned applications range from devices for biological research, to surgical tools and long-term implants. PMID:23868871

  4. Mitochondrial depolarization and electrophysiological changes during ischemia in the rabbit and human heart.

    PubMed

    Sulkin, Matthew S; Boukens, Bas J; Tetlow, Megan; Gutbrod, Sarah R; Ng, Fu Siong; Efimov, Igor R

    2014-10-15

    Instability of the inner mitochondrial membrane potential (ΔΨm) has been implicated in electrical dysfunction, including arrhythmogenesis during ischemia-reperfusion. Monitoring ΔΨm has led to conflicting results, where depolarization has been reported as sporadic and as a propagating wave. The present study was designed to resolve the aforementioned difference and determine the unknown relationship between ΔΨm and electrophysiology. We developed a novel imaging modality for simultaneous optical mapping of ΔΨm and transmembrane potential (Vm). Optical mapping was performed using potentiometric dyes on preparations from 4 mouse hearts, 14 rabbit hearts, and 7 human hearts. Our data showed that during ischemia, ΔΨm depolarization is sporadic and changes asynchronously with electrophysiological changes. Spatially, ΔΨm depolarization was associated with action potential duration shortening but not conduction slowing. Analysis of focal activity indicated that ΔΨm is not different within the myocardium where the focus originates compared with normal ventricular tissue. Overall, our data suggest that during ischemia, mitochondria maintain their function at the expense of sarcolemmal electrophysiology, but ΔΨm depolarization does not have a direct association to ischemia-induced arrhythmias. PMID:25128175

  5. Volume regulatory potassium transport in rabbit and human sickle erythrocytes in vitro

    SciTech Connect

    Al-Rohil, N.S.

    1988-01-01

    One approach to the therapy of sickle cell anemia is to decrease the hemoglobin concentration by inducing a slight swelling of the cell to retard the rate of hemoglobin polymerization. We found that a prolonged incubation of rabbit or human SS red cell in hypotonic medium caused an inactivation of the inactivation of swelling-stimulated potassium transport. The inactivation may have important practical consequences for the therapy of sickle cell anemia. Large cytoskeleton-free vesicles were prepared in order to study the possible role of the spectrin-actin membrane skeleton in the swelling-stimulated and N-ethylmaleimide (NEM)-stimulated transport. NEM pretreatment stimulated {sup 86}Rb efflux in vesicles by a factor of 2.4 + 0.55 (mean {plus minus} S.D.). The NEM effect on {sup 86}Rb efflux was specific in that the {sup 22}Na efflux into a Na medium was not stimulated but actually inhibited. The {sup 86}Rb efflux from the vesicles was not stimulated by hypotonic media. This finding is consistent with a role of the membrane skeleton in the detection and/or transduction of the signal by which cell swelling activates the transport.

  6. Quantitative analysis of naltrexone and 6beta-naltrexol in human, rat, and rabbit plasma by liquid chromatography-electrospray ionization tandem mass spectrometry with application to the pharmacokinetics of Depotrex in rabbits.

    PubMed

    Slawson, Matthew H; Chen, Meng; Moody, David; Comer, Sandra D; Nuwayser, Elie S; Fang, Wenfang B; Foltz, Rodger L

    2007-10-01

    To improve the analysis of naltrexone and its primary metabolite 6beta-naltrexol, a sensitive and specific method for the analysis of subnanogram-per-milliliter concentrations of these analytes in human, rat, and rabbit plasma was developed utilizing liquid chromatography (LC) coupled to electrospray ionization (ESI) tandem mass spectrometry (MS-MS). Plasma samples were extracted utilizing a liquid-liquid extraction technique. Chromatographic separation was achieved using an isocratic solvent system consisting of dilute formic acid and methanol pumped through an ODS-AQ HPLC column. ESI-MS-MS was in the positive ion mode followed by collision-induced dissociation of the protonated molecular ions for naltrexone, 6beta-naltrexol, and their deuterated analogues. This method was validated using Good Laboratory Practice approved methods and was compared to an existing gas chromatography (GC)-MS method by analyzing plasma samples collected from a clinical study. Specificity determined from comparing blank plasma fortified with internal standard to samples fortified with internal standard and analyte at the lower limit of quantitation (LLOQ) from six different human, rat, and rabbit sources demonstrated sufficient signal-to-noise to set the LLOQ at 0.1 ng/mL. This assay has a quantitative range of 0.1-100 ng/mL. The inter- (human only) and intra-assay precision and accuracy in plasma varied by less than 13, 11, and 16% at the LLOQ for both analytes and by less than 10, 10, and 9% at higher concentrations for human, rat, and rabbit plasma, respectively. No loss of analyte was observed after 24 h of room temperature storage in human, rat, and rabbit plasma or three cycles of freezing and thawing of human plasma prior to extraction. Human samples that had been extracted were stable for at least five days when stored frozen at -20 degrees C or for at least two days when stored at room temperature on an autosampler. The GC-MS and LC-MS-MS methods correlated in the measured

  7. Transfection of the Human Heme Oxygenase Gene Into Rabbit Coronary Microvessel Endothelial Cells: Protective Effect Against Heme and Hemoglobin Toxicity

    NASA Astrophysics Data System (ADS)

    Abraham, N. G.; Lavrovsky, Y.; Schwartzman, M. L.; Stoltz, R. A.; Levere, R. D.; Gerritsen, M. E.

    1995-07-01

    Heme oxygenase (HO) is a stress protein and has been suggested to participate in defense mechanisms against agents that may induce oxidative injury such as metals, endotoxin, heme/hemoglobin, and various cytokines. Overexpression of HO in cells might therefore protect against oxidative stress produced by certain of these agents, specifically heme and hemoglobin, by catalyzing their degradation to bilirubin, which itself has antioxidant properties. We report here the successful in vitro transfection of rabbit coronary microvessel endothelial cells with a functioning gene encoding the human HO enzyme. A plasmid containing the cytomegalovirus promoter and the human HO cDNA complexed to cationic liposomes (Lipofectin) was used to transfect rabbit endothelial cells. Cells transfected with human HO exhibited an ≈3.0-fold increase in enzyme activity and expressed a severalfold induction of human HO mRNA as compared with endogenous rabbit HO mRNA. Transfected and nontransfected cells expressed factor VIII antigen and exhibited similar acetylated low-density lipoprotein uptake (two important features that characterize endothelial cells) with >85% of cells staining positive for each marker. Moreover, cells transfected with the human HO gene acquired substantial resistance to toxicity produced by exposure to recombinant hemoglobin and heme as compared with nontransfected cells. The protective effect of HO overexpression against heme/hemoglobin toxicity in endothelial cells shown in these studies provides direct evidence that the inductive response of human HO to such injurious stimuli represents an important tissue adaptive mechanism for moderating the severity of cell damage produced by these blood components.

  8. Acute Radiation Hypotension in the Rabbit: a Model for the Human Radiation Shock Syndrome.

    NASA Astrophysics Data System (ADS)

    Makale, Milan Theodore

    This study has shown that total body irradiation (TBI) of immature (40 to 100 day old) rabbits leads to an acute fall in mean arterial pressure (MAP) 30 to 90 minutes after exposure, which takes no more than about three minutes, and often results in pressures which are less than 50% of the lowest pre-exposure MAP. This is termed acute cardiovascular collapse (ACC). ACC is often accompanied by ECG T-wave elevation, a sharp rise in ear temperature, labored breathing, pupillary constriction, bladder emptying, and loss of abdominal muscle tone. About 73% of 40 to 100 day rabbits exhibit ACC; the others and most older rabbits display gradual pressure reductions (deliberate hypotension) which may be profound, and which may be accompanied by the same changes associated with ACC. ACC and deliberate hypotension occurred in rabbits cannulated in the dorsal aorta, and in non-operated animals. The decline in MAP for all 40 to 100 day cannulated rabbits (deliberate and ACC responders) is 55.4%. The experiments described below only involved 40 to 100 day cannulated TBI rabbits. Heart region irradiation resulted in an average MAP decline of 29.1%, with 1/15 rabbits showing ACC. Heart shielding during TBI reduced the decline in MAP to 19%, with 1/10 rabbits experiencing ACC. These results imply that the heart region, which includes the heart, part of the lungs, neural receptors, roots of the systemic vessels, and the blood, is a sensitive target. Bilateral vagotomy reduced the decline in MAP to 24.9%, and abolished ACC. Atropine (6 mg/kg) reduced the frequency of ACC to 26%, and the decline in MAP to 41.4%. In 11/13 rabbits the voltage generated by left vagal transmission rose after TBI. The vagi appear to participate in radiation hypotension. Heart shielding together with bilateral vagotomy reduced the decline in MAP to only 9.9%, with no ACC responders. The mean right ventricular pressure (MRVP) rose after TBI in 8/10 rabbits. In animals which displayed either ACC or steep

  9. Laying the Foundations for a Human-Predator Conflict Solution: Assessing the Impact of Bonelli's Eagle on Rabbits and Partridges

    PubMed Central

    Moleón, Marcos; Sánchez-Zapata, José A.; Gil-Sánchez, José M.; Barea-Azcón, José M.; Ballesteros-Duperón, Elena; Virgós, Emilio

    2011-01-01

    Background Predation may potentially lead to negative effects on both prey (directly via predators) and predators (indirectly via human persecution). Predation pressure studies are, therefore, of major interest in the fields of theoretical knowledge and conservation of prey or predator species, with wide ramifications and profound implications in human-wildlife conflicts. However, detailed works on this issue in highly valuable –in conservation terms– Mediterranean ecosystems are virtually absent. This paper explores the predator-hunting conflict by examining a paradigmatic, Mediterranean-wide (endangered) predator-two prey (small game) system. Methodology/Principal Findings We estimated the predation impact (‘kill rate’ and ‘predation rate’, i.e., number of prey and proportion of the prey population eaten, respectively) of Bonelli's eagle Aquila fasciata on rabbit Oryctolagus cuniculus and red-legged partridge Alectoris rufa populations in two seasons (the eagle's breeding and non-breeding periods, 100 days each) in SE Spain. The mean estimated kill rate by the seven eagle reproductive units in the study area was c. 304 rabbits and c. 262 partridges in the breeding season, and c. 237 rabbits and c. 121 partridges in the non-breeding period. This resulted in very low predation rates (range: 0.3–2.5%) for both prey and seasons. Conclusions/Significance The potential role of Bonelli's eagles as a limiting factor for rabbits and partridges at the population scale was very poor. The conflict between game profitability and conservation interest of either prey or predators is apparently very localised, and eagles, quarry species and game interests seem compatible in most of the study area. Currently, both the persecution and negative perception of Bonelli's eagle (the ‘partridge-eating eagle’ in Spanish) have a null theoretical basis in most of this area. PMID:21818399

  10. Relevance of Rabbit VX2 Tumor Model for Studies on Human Hepatocellular Carcinoma: A MicroRNA-Based Study

    PubMed Central

    Aravalli, Rajagopal N.; Cressman, Erik N. K.

    2015-01-01

    MicroRNAs are small (~22 nt), noncoding RNA molecules that have critical cellular functions in proliferation, differentiation, angiogenesis and apoptosis. miRNA expression profiling has been used to create signatures of solid tumors and, in many cases, it has been shown to correlate with the severity of the disease. The rabbit VX2 tumor model has been used widely to study a number of human cancers. Our objective in this study is to generate an miRNA signature of the VX2 tumor and to identify miRNAs that are highly expressed in this aggressive tumor. In this study, we performed miRNA profiling of the rabbit VX2 tumor using a microarray that has probes for 1292 unique miRNAs. Their expression in tumor samples was quantified and analyzed. We found that 35 miRNAs were significantly up-regulated in the VX2 tumor. Among these, 13 human miRNAs and eight members of the let-7 family were previously identified in cancers. In addition, we show that the expression of three miRNAs (miR-923, miR-1275, and miR-1308) is novel for the rabbit VX2 tumor, and their expression was not previously shown to be associated with any type of cancer. For the first time, we show the miRNA signature profile for a solid tumor in a rabbit model. miRNAs highly expressed in the VX2 tumor may serve as novel candidates for molecular biomarkers and as potential drug targets. PMID:26690234

  11. Developmental Toxicity and Fertility Assessment in Rabbits with Tabalumab: A Human IgG4 Monoclonal Antibody.

    PubMed

    Breslin, William J; Hilbish, Kim G; Martin, Jennifer A; Halstead, Carolyn A; Edwards, Tammy L

    2015-06-01

    Tabalumab is a human immunoglobulin G subclass 4 monoclonal antibody that has been under development for autoimmune disorders. Tabalumab has full neutralizing activity against both soluble and membrane B-cell activating factor, a B-cell survival factor. The objectives of these studies were to assess the effects of tabalumab on embryo-fetal development and on male (M) and female (F) fertility in rabbits, a pharmacologically relevant species. Doses were administered at 0 (vehicle control), 0.3 (embryo-fetal study only), 1.0, and 30 mg/kg. In the embryo-fetal study, pregnant rabbits does were given a single dose by intravenous injection on gestation day (GD) 7. In the fertility studies, tabalumab was administered by intravenous injection every 7 days starting 2 (F) or 4 (M) weeks before mating, during cohabitation, and until necropsy (M) or through GD 18 (F). Treated animals were mated with untreated partners. Parental clinical signs, body weight, food consumption, blood lymphocyte phenotyping, organ weights, morphologic pathology, ovarian and uterine observations, sperm parameters, and fertility indices were evaluated along with conceptus viability, weight, and morphology. Exposure assessments were made in all main study animals and satellite animals. No adverse parental, reproductive, or developmental effects were observed in any study at any dose. A pharmacodynamic response consisting of dose-dependent decreases in the percent and number of total B lymphocytes and increases in the percent and/or number of total T lymphocytes was observed in parental rabbits at 1.0 and 30 mg/kg. In conclusion, no adverse reproductive or developmental effects were observed in rabbits following exposure to tabalumab at doses as high as 30 mg/kg and exposures at least 14-fold greater than human exposure levels. PMID:26195315

  12. Transport of the subclasses of human IgG across the yolk-sac of the foetal rabbit

    PubMed Central

    Hemmings, W. A.

    1974-01-01

    The four subclasses of human IgG were labelled either with 125I or 131I and injected into rabbit uteri (24 days pregnant) in pairs. Transmission to the foetal circulation was measured 1 day later. It was found that all four sub-classes are transmitted, though IgG1 enters most readily. Whole labelled human IgG fast and slow electrophoretic fractions prepared by DEAE chromatography were also injected and an isoelectrofocusing analysis carried out on the injected IgG and the foetal serum. There was considerable variation of transmission even between adjacent peaks of the IEF pattern. PMID:4435834

  13. The Immunologic Injury Composite with Balloon Injury Leads to Dyslipidemia: A Robust Rabbit Model of Human Atherosclerosis and Vulnerable Plaque

    PubMed Central

    Zhang, Guangyin; Li, Ming; Li, Liangjun; Xu, Yingzhi; Li, Peng; Yang, Cui; Zhou, Yanan; Zhang, Junping

    2012-01-01

    Atherosclerosis is a condition in which a lipid deposition, thrombus formation, immune cell infiltration, and a chronic inflammatory response, but its systemic study has been hampered by the lack of suitable animal models, especially in herbalism fields. We have tried to perform a perfect animal model that completely replicates the stages of human atherosclerosis. This is the first combined study about the immunologic injury and balloon injury based on the cholesterol diet. In this study, we developed a modified protocol of the white rabbit model that could represent a novel approach to studying human atherosclerosis and vulnerable plaque. PMID:22988422

  14. The role of VEGF pathways in human physiologic and pathologic angiogenesis.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In pre-clinical models VEGF is a potent stimulant of both physiologic and pathologic angiogenesis. Conversely, anti-VEGF regimens have successfully inhibited angiogenesis both in vitro and in vivo. We hypothesized that VEGF would stimulate both physiologic and pathologic angiogenesis in a human-ba...

  15. Evaluation of human recombinant bone morphogenetic protein-2-loaded tricalcium phosphate implants in rabbits' bone defects.

    PubMed

    Laffargue, P; Hildebrand, H F; Rtaimate, M; Frayssinet, P; Amoureux, J P; Marchandise, X

    1999-08-01

    Porous beta-tricalcium phosphate (betaTCP) has osteoconductive properties. The adsorption of human recombinant bone morphogenetic protein-2 (rhBMP-2) onto TCP could realize an osteoinductive bone substitute. We evaluated it on an animal model using dual-energy X-ray absorptiometry (DEXA) and solid-state 31P nuclear magnetic resonance (NMR) spectroscopy. BetaTCP cylinders loaded with rhBMP-2 were implanted into rabbits' femoral condyle bone defects, and betaTCP alone as control into the contralateral femur. We studied two different doses of rhBMP-2 (10 and 40 microg) on two groups of four animals. Evaluation consisted in radiography, histology, and histomorphometry, DEXA, and NMR spectroscopy using an original method of quantification. With both doses of rhBMP-2, we observed on radiographs an increase of trabecular bone around implants. Histology showed resorption of the ceramic, trabecular bone with osteoblasts and osteoid substance around the implants, and colonization inside the porous betaTCP by new bone formed. Histomorphometry showed that the osteoid surface (OS/BS) was greatest with the high dose of rhBMP-2. The difference was slight between the low dose of rhBMP-2 and control. DEXA showed a dose-dependent increase of bone mineral density of rhBMP-2-loaded betaTCP vs. control. NMR spectroscopy confirmed that the amount of new bone formed in betaTCP was greater when betaTCP carried rhBMP-2, and increased with the dose of rhBMP-2 used. We showed that betaTCP was a good matrix for rhBMP-2, which gave it osteoinductive properties in an orthotopic site, in a dose-dependent manner. Thus, such composite biomaterial seems to be of great interest in reconstructive bone surgery. Further studies are needed in clinical practice to determine optimal doses. PMID:10458276

  16. Blockage of Src by Specific siRNA as a Novel Therapeutic Strategy to Prevent Destructive Repair in Steroid-Associated Osteonecrosis in Rabbits.

    PubMed

    Zheng, Li-zhen; Cao, Hui-juan; Chen, Shi-hui; Tang, Tao; Fu, Wei-min; Huang, Le; Chow, Dick Ho Kiu; Wang, Yi-xiang; Griffith, James Francis; He, Wei; Zhou, Hong; Zhao, De-wei; Zhang, Ge; Wang, Xin-luan; Qin, Ling

    2015-11-01

    Vascular hyperpermeability and highly upregulated bone resorption in the destructive repair progress of steroid-associated osteonecrosis (SAON) are associated with a high expression of VEGF and high Src activity (Src is encoded by the cellular sarcoma [c-src] gene). This study was designed to prove our hypothesis that blocking the VEGF-Src signaling pathway by specific Src siRNA is able to prevent destructive repair in a SAON rabbit model. Destructive repair in SAON was induced in rabbits. At 2, 4, and 6 weeks after SAON induction, VEGF, anti-VEGF, Src siRNA, Src siRNA+VEGF, control siRNA, and saline were introduced via intramedullary injection into proximal femora for each group, respectively. Vascularization and permeability were quantified by dynamic contrast-enhanced (DCE) MRI. At week 6 after SAON induction, proximal femurs were dissected for micro-computed tomography (μCT)-based trabecular architecture with finite element analysis (FEA), μCT-based angiography, and histological analysis. Histological evaluation revealed that VEGF enhanced destructive repair, whereas anti-VEGF prevented destructive repair and Src siRNA and Src siRNA+VEGF prevented destructive repair and enhanced reparative osteogenesis. Findings of angiography and histomorphometry were consistent with those determined by DCE MRI. Src siRNA inhibited VEGF-mediated vascular hyperpermeability but preserved VEGF-induced neovascularization. Bone resorption was enhanced in the VEGF group and inhibited in the anti-VEGF, Src siRNA, Src siRNA+VEGF groups as determined by both 3D μCT and 2D histomorphometry. FEA showed higher estimated failure load in the Src siRNA and Src siRNA+VEGF groups when compared to the vehicle control group. Blockage of VEGF-Src signaling pathway by specific Src siRNA was able to prevent steroid-associated destructive repair while improving reconstructive repair in SAON, which might become a novel therapeutic strategy. PMID:25917347

  17. Engraftment Potential of Adipose Tissue-Derived Human Mesenchymal Stem Cells After Transplantation in the Fetal Rabbit

    PubMed Central

    Martínez-González, Itziar; Moreno, Rafael; Petriz, Jordi; Gratacós, Eduard

    2012-01-01

    Due to their favorable intrinsic features, including engraftment, differentiation, and immunomodulatory potential, adult mesenchymal stem cells (MSCs) have been proposed for therapeutic in utero intervention. Further improvement of such attributes for particular diseases might merely be achieved by ex vivo MSC genetic engineering previous to transplantation. Here, we evaluated for the first time the feasibility, biodistribution, long-term engraftment, and transgenic enhanced green fluorescent protein (EGFP) expression of genetically engineered human adipose tissue-derived MSCs (EGFP+-ASCs) after intra-amniotic xenotransplantation at E17 of gestation into our validated pregnant rabbit model. Overall, the procedure was safe (86.4% survival rate; absence of anatomical defects). Stable, low-level engraftment of EGFP+-ASCs was confirmed by assessing the presence of the pWT-EGFP lentiviral provirus in the young transplanted rabbit tissues. Accordingly, similar frequencies of provirus-positive animals were found at both 8 weeks (60%) and 16 weeks (66.7%) after in utero intervention. The presence of EGFP+-ASCs was more frequent in respiratory epithelia (lung and trachea), according to the route of administration. However, we were unable to detect EGFP expression, neither by real-time polymerase chain reaction nor by immunohistochemistry, in the provirus-positive tissues, suggesting EGFP transgene silencing mediated by epigenetic events. Moreover, we noticed lack of both host cellular immune responses against xenogeneic ASCs and humoral immune responses against transgenic EGFP. Therefore, the fetal microchimerism achieved by the EGFP+-ASCs in the young rabbit hosts indicates induction of donor-specific tolerance after fetal rabbit xenotransplantation, which should boost postnatal transplantation for the early treatment/prevention of many devastating congenital disorders. PMID:22738094

  18. FDTD analysis of temperature elevation in the lens of human and rabbit models due to near-field and far-field exposures at 2.45 GHz.

    PubMed

    Oizumi, Takuya; Laakso, Ilkka; Hirata, Akimasa; Fujiwara, Osamu; Watanabe, Soichi; Taki, Masao; Kojima, Masami; Sasaki, Hiroshi; Sasaki, Kazuyuki

    2013-07-01

    The eye is said to be one of the most sensitive organs to microwave heating. According to previous studies, the possibility of microwave-induced cataract formation has been experimentally investigated in rabbit and monkey eyes, but not for the human eye due to ethical reasons. In the present study, the temperature elevation in the lens, the skin around the eye and the core temperature of numerical human and rabbit models for far-field and near-field exposures at 2.45 GHz are investigated. The temperature elevations in the human and rabbit models were compared with the threshold temperatures for inducing cataracts, thermal pain in the skin and reversible health effects such as heat exhaustion or heat stroke. For plane-wave exposure, the core temperature elevation is shown to be essential both in the human and in the rabbit models as suggested in the international guidelines and standards. For localised exposure of the human eye, the temperature elevation of the skin was essential, and the lens temperature did not reach its threshold for thermal pain. On the other hand, the lens temperature elevation was found to be dominant for the rabbit eye. PMID:23390146

  19. In vitro CD4+ lymphocyte transformation and infection in a rabbit model with a molecular clone of human T-cell lymphotrophic virus type 1.

    PubMed Central

    Collins, N D; Newbound, G C; Ratner, L; Lairmore, M D

    1996-01-01

    We transfected human and rabbit peripheral blood mononuclear cells (PBMC) with the ACH molecular clone of human T-cell lymphotropic virus type 1 (HTLV-1) to study its in vitro and in vivo properties. PBMC transfected with ACH were shown to transfer infection to naive PBMC. ACH transformed rabbit PBMC, as indicated by interleukin-2-independent proliferation of a transfectant culture. This transformant culture was shown by flow cytometric analysis to be a CD4+ CD25+ T-lymphocyte population containing, as determined by Southern blot analysis, at least three integrated HTLV-1 proviral copies. HTLV-1 infection was produced in rabbits inoculated with ACH-transfected, irradiated PBMC. Inoculated rabbits seroconverted to positivity for antibodies against HTLV-1 and had steady or rising HTLV-1 enzyme-linked immunosorbent assay antibody titers. Western blot (immunoblot) analysis revealed sustained seroconversion of rabbits to positivity for antibodies against all major viral antigenic determinants. Infection of rabbits was further demonstrated by antigen capture assay of p24 in PBMC and lymph node cultures and PCR amplification of proviral sequences from PBMC. These data suggest that ACH, like wild-type HTLV-1, infects and transforms primary CD4+ T lymphocytes and is infectious in vivo. This clone will facilitate investigations into the role of viral genes on biological properties of HTLV-1 in vitro and in vivo. PMID:8794375

  20. Arachidonic acid metabolism in the platelets and neutrophils of diabetic rabbit and human subjects

    SciTech Connect

    Greco, N.J.

    1985-01-01

    An alteration of arachidonic acid metabolism to prostaglandins and leukotrienes from platelets and polymorphonuclear leukocytes respectively is evident in subjects with diabetes mellitus. There is evidence of altered platelet/vascular wall interactions in diabetes mellitus and evidence that polymorphonuclear leukocytes influence the vascular walls. Theories on the pathogenesis of atherosclerosis include both blood cells. Platelet hypersensitivity is evident in those platelets from the alloxan-induced diabetic rabbit either suspended in plasma or buffer. Arachidonic acid- and collagen-induced platelet aggregation, release of /sup 14/serotonin, and T x B/sub 2/ and 12-HETE production is enhanced when responses of diabetic platelets are compared to control platelets. Control rabbit neutrophils produce more LTB/sub 4/, LTB/sub 4/ isomers and 5-HETE than diabetic rabbits neutrophils. Decreased synthesis from diabetic rabbit neutrophils is not explained by increased catabolism of LTB/sub 4/, reesterification of 5-HETE, or increased eicosanoid formation. These experiments demonstrate both platelet and neutrophil dysfunction in diabetic subjects. Because of the involvement of these cells in regulating circulatory homeostatis, abnormal behavior could aggravate the atherosclerotic process. Platelet and neutrophil dysfunctions are noted before macroscopic vascular lesions are apparent suggesting an important role in the pathogenesis of atherosclerosis.

  1. Disposal rabbit

    DOEpatents

    Lewis, L.C.; Trammell, D.R.

    1983-10-12

    A disposable rabbit for transferring radioactive samples in a pneumatic transfer system comprises aerated plastic shaped in such a manner as to hold a radioactive sample and aerated such that dissolution of the rabbit in a solvent followed by evaporation of the solid yields solid waste material having a volume significantly smaller than the original volume of the rabbit.

  2. Disposable rabbit

    DOEpatents

    Lewis, Leroy C.; Trammell, David R.

    1986-01-01

    A disposable rabbit for transferring radioactive samples in a pneumatic transfer system comprises aerated plastic shaped in such a manner as to hold a radioactive sample and aerated such that dissolution of the rabbit in a solvent followed by evaporation of the solid yields solid waste material having a volume significantly smaller than the original volume of the rabbit.

  3. Effects of recombinant human interleukin-10 on Treg cells, IL-10 and TGF-β in transplantation of rabbit skin.

    PubMed

    Liu, Kai Shan; Fan, Xiao Qin; Zhang, Lei; Wen, Qiong Na; Feng, Ji Hong; Chen, Fu Chao; Luo, Jun Min; Sun, Wan Bang

    2014-02-01

    The current study aimed to investigate the rejection and survival time of grafted skin, and the changes of Treg cells, interleukin 10 (IL-10) and transforming growth factor-β (TGF-β) in peripheral blood following skin transplantation with recombinant human interleukin-10 (rhIL-10) or cyclosporin A (CsA), as well as the role of IL-10 in immunological rejection mechanisms. A total of 36 rabbits were divided into two groups. The skin of a donor rabbit was transplanted onto the back of one receptor rabbit. Receptors were randomly divided into six groups, including rhIL-10 low-dose (5 µg/kg/d), rhIL-10 high-dose (10 µg/kg/d), CsA low-dose (5 mg/kg/d), CsA high-dose (10 mg/kg/d), rhIL-10 (5 µg/kg/d) and CsA (5 mg/kg/d) and negative control normal saline (NS; 1 ml/d). All groups received intramuscular drug injection for ten days, beginning one day prior to skin transplantation surgery. Following transplantation, each rabbit's peripheral blood was collected at different times. The changes of CD4+CD25+ regulatory T cells, IL-10 and TGF-β were determined by flow cytometry and enzyme-linked immunosorbent assay. When compared with the control group, the rejection and survival times of the experimental groups were longer following skin graft. Compared with the two CsA groups and the control group, the proportion of CD4+CD25+ regulatory T cells of rhIL-10 groups was significantly upregulated on the 4th and 7th days following surgery. However, TGF-β levels were not significantly different. Data suggested that the concentration of IL-10 was positively correlated with the proportion of CD4+CD25+ regulatory T cells. In addition, IL-10 may delay the rejection time of rabbit skin transplantation and prolong the survival time. Thus, the role of IL-10 in inhibited allograft rejection may be associated with CD4+CD25+ regulatory T cells and IL-10, and may be independent of TGF-β. PMID:24270972

  4. Plasma clearance of human extracellular-superoxide dismutase C in rabbits

    SciTech Connect

    Karlsson, K.; Marklund, S.L.

    1988-09-01

    Extracellular-superoxide dismutase (EC-SOD) is heterogenous in the vasculature with regard to heparin affinity and can be separated into three fractions: A, without affinity; B, with weak affinity; and C, with relatively strong heparin affinity. The plasma clearance of intravenously injected 125I-labeled and unlabeled human EC-SOD C was studied in rabbits. About 90% of injected 125I-EC-SOD C was eliminated from the blood within 5-10 min. Injection of heparin after 10 or 20 min led to an immediate release of all sequestered 125I-EC-SOD C back to the blood plasma. Later injections of heparin led to diminished release, although release could still be demonstrated after 72 h. A half-time of approximately 10 h could be calculated for heparin-releasable 125I-EC-SOD C. Unlabeled EC-SOD C, determined as enzymic activity and with ELISA, was likewise sequestered and released to the same degree as 125I-labeled EC-SOD C by heparin as tested at 20 min and 5 h. The immediacy of the heparin-induced release indicates that the sequestered enzyme had been bound to endothelial cell surfaces. The length of the half-time suggests that the putative cell surface binding has a physiological function and is not primarily a step in enzyme degradation. The distribution of sequestered 125I-labeled EC-SOD C to different organs was determined at times between 10 min and 24 h. Of the organs, the liver contained the most 125I-EC-SOD C, followed by kidney, spleen, heart, and lung. At all investigated times, the content in the analyzed organs was nearly as large as the amount that could be promptly released to plasma by intravenous heparin. This indicates that almost all 125I-EC-SOD C in the organs was present on endothelial cell surfaces and was not bound by other tissue cell surfaces, or was present within the cells.

  5. Magnetic resonance knee arthrography. Enhanced contrast by gadolinium complex in the rabbit and in humans.

    PubMed

    Engel, A

    1990-01-01

    This study contains the fundamentals and the technique of the intraarticular application of an MRI contrast agent in connection with magnetic resonance imaging (MRI arthrography). It also presents the resulting clinical relevance for knee joint diagnostics. The significance of MRI arthrography is linked above all to the central question of whether or not it is possible to depict the hyaline cartilage, its surface and its thickness with the help of MRI arthrography. MRI arthrography was used for in vitro examinations of rabbit knee joint cartilage and human joint cartilage. The in vivo application was carried out in 73 patients. Apart from the metric evaluation and the assessment of the information content of the MRI image, the corresponding histologic sections were made in 20 knee joints in order to compare the cartilage surface and the thickness of the cartilage with the results in the MRI image. The optimum amount of contrast agent for visualization was determined, the uptake and clearance of the contrast agent from the cartilage were assessed, and trace elements from the cartilage were also analyzed. The examination showed that the molecular structure of the contrast agent (gadolinium-DTPA) does not prevent the uptake of the contrast agent into the matrix of the hyaline cartilage. But this process is reversible. Thus, 14 hours after the intraarticular application of the contrast agent no measurable traces of gadolinium-DTPA could be established. The intraarticular application of the contrast agent also made it possible to achieve a constant and reproducible visualization of all joint structures. This affected mainly the surface of the hyaline cartilage. The best imaging quality was achieved with intraarticular application of 30 to 40 mL of a 2 mmolar solution of gadolinium-DTPA. The technique used for the intraarticular application is the same as for the common procedures of knee joint aspiration. The clinical importance of MRI arthrography lies in the fact that

  6. Production, isolation, and characterization of rabbit anti-idiotypic antibodies directed against human antithyrotrophin receptor antibodies.

    PubMed Central

    Baker, J R; Lukes, Y G; Burman, K D

    1984-01-01

    Previous studies have shown that anti-idiotypic antibodies can be developed in vivo through animal immunization with idiotype, and that these antibodies can be isolated from other anti-immunoglobulin antibodies by affinity purification. These techniques have relied on large amounts of idiotype, which were produced either by hyperimmunization or by monoclonal antibodies, to serve as the affinity adsorbent. In the present study, we produced anti-idiotypic antibodies to human anti-thyroid-stimulating hormone (TSH) receptor antibodies by first injecting rabbits with (TSH receptor purified) IgG from Graves' patients. The resulting antiserum was then adsorbed with Sepharose-coupled TSH in an attempt to specifically bind and isolate the anti-idiotype. The antibody obtained from this process was shown to bind specifically to TSH receptor-binding antibodies from Graves' patients, and this binding could be inhibited by 56% with the addition of 10(-4) M TSH but not by HCG (10(-2) M). The anti-idiotype also bound to TSH, and this binding could be specifically inhibited by receptor-purified Graves' IgG (60% inhibition at 10 micrograms/ml IgG), but not by IgG from normal subjects (no inhibition at 50 micrograms/ml IgG). In a TSH receptor binding assay, the anti-idiotype could inhibit TSH receptor binding in Graves' sera at a 1,000-fold lower concentration than could anti-kappa/lambda antiserum; the anti-idiotypic antiserum also inhibited in vitro TSH-mediated adenylate cyclase stimulation at an IgG concentration of 5 micrograms/ml, while heterologous anti-TSH antisera and normal IgG at similar concentrations had no effect. Finally, despite being generated against a single patient's TSH receptor binding antibody, the anti-idiotype was able to block TSH receptor binding in the serum of six other Graves' patients, thus suggesting that there may be conformational conservation in the antigen that is recognized by different individuals' TSH receptor-binding immunoglobulins. PMID

  7. Iloprost- and isoproterenol-induced increases in cAMP are regulated by different phosphodiesterases in erythrocytes of both rabbits and humans

    PubMed Central

    Adderley, Shaquria P.; Dufaux, Eileen A.; Sridharan, Meera; Bowles, Elizabeth A.; Hanson, Madelyn S.; Stephenson, Alan H.; Ellsworth, Mary L.; Sprague, Randy S.

    2009-01-01

    Activation of the G protein Gs results in increases in cAMP, a necessary step in the pathway for ATP release from rabbit and human erythrocytes. In all cells, the level of cAMP is the product of its synthesis by adenylyl cyclase and its hydrolysis by phosphodiesterases (PDEs). Both iloprost (Ilo), a PGI2 analog, and isoproterenol (Iso), a β-agonist, stimulate receptor-mediated increases in cAMP in rabbit and human erythrocytes. However, the specific PDEs associated with each of these signaling pathways in the erythrocyte have not been fully characterized. Previously, we reported that PDE3B is present in rabbit and human erythrocyte membranes and that PDE3 inhibitors potentiate Ilo-induced increases in cAMP. Here we report that inhibitors of either PDE2 or PDE4, erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA) and rolipram, respectively, potentiate Iso-induced increases in cAMP in rabbit and human erythrocytes. Importantly, these inhibitors had no effect on cAMP increases associated with the incubation of erythrocytes with Ilo. In addition, we establish, for the first time, the presence of PDE2A protein in rabbit and human erythrocyte membranes. Finally, we determined that preincubation of human erythrocytes with EHNA and rolipram together potentiate Iso-induced ATP release, whereas preincubation with cilostazol enhances Ilo-induced release of ATP. These results are consistent with the hypothesis that, in rabbit and human erythrocytes, Ilo-induced increases in cAMP and ATP release are regulated by PDE3, whereas those associated with Iso are regulated by the activities of both PDE2 and PDE4. These studies demonstrate that PDE activity in these cells is localized to specific signaling pathways. PMID:19252089

  8. Distribution of Purkinje cell-specific Zebrin-II/aldolase C immunoreactivity in the mouse, rat, rabbit, and human retina.

    PubMed

    Caffé, A R; Von Schantz, M; Szél, A; Voogd, J; Van Veen, T

    1994-10-01

    The developmental, genetic, and biochemical similarities that have been observed between the cerebellum and retina form the basis for ongoing investigations into retinal expression of cerebellar-specific proteins. We have examined the mouse, rat, rabbit, and human retina for expression of a protein that is present in parasagittal Purkinje cell strips and that is recognized by the antibody Zebrin-II. This protein has recently been identified as a member of the aldolase C isoenzymes. Western blotting and immunocytochemistry have been used. The monoclonal antibody Zebrin-II recognized a prominent 36 kDa protein band on immunoblots of both the cerebellum and the retina of the examined species. Immunocytochemistry showed that, in the three nonhuman species, cells were stained in the ganglion cell layer (GCL). In addition, in the mouse and rabbit, cells in the inner nuclear layer (INL) were also labeled. Except for the visual streak, there were more immunopositive cells in the rabbit GCL and INL than in corresponding areas of the mouse retina. In the human, in contrast to the other species, the photoreceptor cell layer was strongly aldolase C immunoreactive. In all species except for the rat, the photoreceptor inner segments also displayed a weak labeling. The results show that this aldolase C isoenzyme is another protein that is selectively expressed by the cerebellum and retina. Furthermore, the retinal expression is species specific, and this pattern seems to show a good correlation with the oxygenation level of the individual compartments. The indication that this aldolase C isoenzyme has specific developmental functions in the retina provides additional clues for our understanding of cerebellar organization. PMID:7814693

  9. Clostridium perfringens Type A Food Poisoning II. Response of the Rabbit Ileum as an Indication of Enteropathogenicity of Strains of Clostridium perfringens in Human Beings

    PubMed Central

    Strong, Dorothy H.; Duncan, Charles L.; Perna, Giuseppe

    1971-01-01

    The effect of feeding human beings individual strains of Clostridium perfringens or culture filtrates thereof was examined. The strains selected for challenge included both those which had previously been shown to produce fluid accumulation in the ligated ileum or overt diarrhea when injected into the nonligated ileum of the rabbit, or had produced both, and those which did not regularly produce these responses. Challenge doses prepared by allowing each strain to grow in beef stew for 3 hr at 46 C resulted in a 61% incidence of diarrhea when rabbit-positive cells were used. No diarrhea occurred among the subjects fed rabbit-negative strains prepared in a similar manner. The procedures employed in preparing the challenge dose appeared to influence the results obtained. When cell-free filtrates were fed, 4 of 15 persons consuming filtrates from rabbit-positive strains developed diarrhea. All subjects fed filtrates from rabbit-negative strains remained free from diarrhea. Serological tests were carried out to compare the identity of the strains of C. perfringens consumed by the subjects and those excreted in the feces. Heat resistance measured as D100 values varied greatly among the rabbit-positive strains. PMID:16557937

  10. Auditory Distance Coding in Rabbit Midbrain Neurons and Human Perception: Monaural Amplitude Modulation Depth as a Cue

    PubMed Central

    Zahorik, Pavel; Carney, Laurel H.; Bishop, Brian B.; Kuwada, Shigeyuki

    2015-01-01

    Mechanisms underlying sound source distance localization are not well understood. Here we tested the hypothesis that a novel mechanism can create monaural distance sensitivity: a combination of auditory midbrain neurons' sensitivity to amplitude modulation (AM) depth and distance-dependent loss of AM in reverberation. We used virtual auditory space (VAS) methods for sounds at various distances in anechoic and reverberant environments. Stimulus level was constant across distance. With increasing modulation depth, some rabbit inferior colliculus neurons increased firing rates whereas others decreased. These neurons exhibited monotonic relationships between firing rates and distance for monaurally presented noise when two conditions were met: (1) the sound had AM, and (2) the environment was reverberant. The firing rates as a function of distance remained approximately constant without AM in either environment and, in an anechoic condition, even with AM. We corroborated this finding by reproducing the distance sensitivity using a neural model. We also conducted a human psychophysical study using similar methods. Normal-hearing listeners reported perceived distance in response to monaural 1 octave 4 kHz noise source sounds presented at distances of 35–200 cm. We found parallels between the rabbit neural and human responses. In both, sound distance could be discriminated only if the monaural sound in reverberation had AM. These observations support the hypothesis. When other cues are available (e.g., in binaural hearing), how much the auditory system actually uses the AM as a distance cue remains to be determined. PMID:25834060

  11. Auditory distance coding in rabbit midbrain neurons and human perception: monaural amplitude modulation depth as a cue.

    PubMed

    Kim, Duck O; Zahorik, Pavel; Carney, Laurel H; Bishop, Brian B; Kuwada, Shigeyuki

    2015-04-01

    Mechanisms underlying sound source distance localization are not well understood. Here we tested the hypothesis that a novel mechanism can create monaural distance sensitivity: a combination of auditory midbrain neurons' sensitivity to amplitude modulation (AM) depth and distance-dependent loss of AM in reverberation. We used virtual auditory space (VAS) methods for sounds at various distances in anechoic and reverberant environments. Stimulus level was constant across distance. With increasing modulation depth, some rabbit inferior colliculus neurons increased firing rates whereas others decreased. These neurons exhibited monotonic relationships between firing rates and distance for monaurally presented noise when two conditions were met: (1) the sound had AM, and (2) the environment was reverberant. The firing rates as a function of distance remained approximately constant without AM in either environment and, in an anechoic condition, even with AM. We corroborated this finding by reproducing the distance sensitivity using a neural model. We also conducted a human psychophysical study using similar methods. Normal-hearing listeners reported perceived distance in response to monaural 1 octave 4 kHz noise source sounds presented at distances of 35-200 cm. We found parallels between the rabbit neural and human responses. In both, sound distance could be discriminated only if the monaural sound in reverberation had AM. These observations support the hypothesis. When other cues are available (e.g., in binaural hearing), how much the auditory system actually uses the AM as a distance cue remains to be determined. PMID:25834060

  12. CRISPR/Cas9-mediated GJA8 knockout in rabbits recapitulates human congenital cataracts.

    PubMed

    Yuan, Lin; Sui, Tingting; Chen, Mao; Deng, Jichao; Huang, Yongye; Zeng, Jian; Lv, Qingyan; Song, Yuning; Li, Zhanjun; Lai, Liangxue

    2016-01-01

    Cataracts are the leading cause of vision loss in the world, although surgical treatment can restore vision in cataract patients. Until now, there have been no adequate animal models for in vivo studies of artificial lens safety and drug interactions. Genetic studies have demonstrated that GJA8 is involved in maintaining lens opacity and proper lens development. In this study, a cataract model with GJA8 gene knockout was developed via co-injection of Cas9/sgRNA mRNA into rabbit zygotes. Our results showed that gene mutation efficiency in the GJA8 locus reached 98.7% in embryos and 100% in pups, demonstrating that the Cas9/sgRNA system is a highly efficient tool for gene editing in rabbits. In agreement with other studies, our genetic and histology results showed that impaired GJA8 function caused microphthalmia, small lens size and cataracts. In summary, our novel rabbit model of cataracts will be an important drug-screening tool for cataract prevention and treatment. PMID:26912477

  13. CRISPR/Cas9-mediated GJA8 knockout in rabbits recapitulates human congenital cataracts

    PubMed Central

    Yuan, Lin; Sui, Tingting; Chen, Mao; Deng, Jichao; Huang, Yongye; Zeng, Jian; Lv, Qingyan; Song, Yuning; Li, Zhanjun; Lai, Liangxue

    2016-01-01

    Cataracts are the leading cause of vision loss in the world, although surgical treatment can restore vision in cataract patients. Until now, there have been no adequate animal models for in vivo studies of artificial lens safety and drug interactions. Genetic studies have demonstrated that GJA8 is involved in maintaining lens opacity and proper lens development. In this study, a cataract model with GJA8 gene knockout was developed via co-injection of Cas9/sgRNA mRNA into rabbit zygotes. Our results showed that gene mutation efficiency in the GJA8 locus reached 98.7% in embryos and 100% in pups, demonstrating that the Cas9/sgRNA system is a highly efficient tool for gene editing in rabbits. In agreement with other studies, our genetic and histology results showed that impaired GJA8 function caused microphthalmia, small lens size and cataracts. In summary, our novel rabbit model of cataracts will be an important drug-screening tool for cataract prevention and treatment. PMID:26912477

  14. Goat anti-rabbit IgG conjugated fluorescent dye-doped silica nanoparticles for human breast carcinoma cell recognition.

    PubMed

    Chen, Min-Yan; Chen, Ze-Zhong; Wu, Ling-Ling; Tang, Hong-Wu; Pang, Dai-Wen

    2013-11-12

    We report an indirect method for cancer cell recognition using photostable fluorescent silica nanoprobes as biological labels. The dye-doped fluorescent silica nanoparticles were synthesized using the water-in-oil (W/O) reverse microemulsion method. The silica matrix was produced by the controlled hydrolysis of tetraethylorthosilicate (TEOS) in water nanodroplets with the initiation of ammonia (NH3·H2O). Fluorescein isothiocyanate (FITC) or rhodamine B isothiocyanate conjugated with dextran (RBITC-Dextran) was doped in silica nanoparticles (NPs) with a size of 60 ± 5 nm as a fluorescent signal element by covalent bonding and steric hindrance, respectively. The secondary antibody, goat anti-rabbit IgG, was conjugated on the surface of the PEG-terminated modified FITC-doped or RBITC-Dextran-doped silica nanoparticles (PFSiNPs or PBSiNPs) by covalent binding to the PEG linkers using the cyanogen bromide method. The concentrations of goat anti-rabbit IgG covering the nanoprobes were quantified via the Bradford method. In the proof-of-concept experiment, an epithelial cell adhesion molecule (EpCAM) on the human breast cancer SK-Br-3 cell surface was used as the tumor marker, and the nanoparticle functionalized with rabbit anti-EpCAM antibody was employed as the nanoprobe for cancer cell recognition. Compared with fluorescent dye labeled IgG (FITC-IgG and RBITC-IgG), the designed nanoprobes display dramatically increased stability of fluorescence as well as photostability under continuous irradiation. PMID:24179992

  15. Recombinant human bone morphogenetic protein-2 suspended in fibrin glue enhances bone formation during distraction osteogenesis in rabbits

    PubMed Central

    Li, Yunfeng; Li, Rui; Hu, Jing; Song, Donghui; Jiang, Xiaowen

    2016-01-01

    Introduction Bone morphogenetic protein-2 (BMP-2) has high potential for bone formation, but its in vivo effects are unpredictable due to the short life time. This study was designed to evaluate the effects of recombinant human (rh) BMP-2 suspended in fibrin on bone formation during distraction osteogenesis (DO) in rabbits. Material and methods The in vitro release kinetics of rhBMP-2 suspended in fibrin was tested using an enzyme-linked immunosorbent assay. Unilateral tibial lengthening for 10 mm was achieved in 48 rabbits. At the completion of osteodistraction, vehicle, fibrin, rhBMP-2 or rhBMP-2 suspended in fibrin (rhBMP-2 + fibrin) was injected into the center of the lengthened gap, with 12 animals in each group. Eight weeks later, the distracted callus was examined by histology, micro-CT and biomechanical testing. Radiographs of the distracted tibiae were taken at both 4 and 8 weeks after drug treatment. Results It was found that fibrin prolonged the life span of rhBMP-2 in vitro with sustained release during 17 days. The rhBMP-2 + fibrin treated animals showed the best results in bone mineral density, bone volume fraction, cortical bone thickness by micro-CT evaluation and mechanical properties by the three-point bending test when compared to the other groups (p < 0.05). In histological images, rhBMP-2 + fibrin treatment showed increased callus formation and better gap bridging compared to the other groups. Conclusions The results of this study suggest that fibrin holds promise to be a good carrier of rhBMP-2, and rhBMP-2 suspended in fibrin showed a stronger promoting effect on bone formation during DO in rabbits. PMID:27279839

  16. Using the Past to Inform the Future: Anti-VEGF Therapy as a Road Map to Develop Novel Therapies for Diabetic Retinopathy

    PubMed Central

    Titchenell, Paul M.; Antonetti, David A.

    2013-01-01

    Therapies targeting vascular endothelial growth factor (VEGF) are revolutionizing the treatment of diabetic retinopathy (DR) and diabetic macular edema (DME). In August 2012, ranibizumab, a monoclonal antibody fragment targeting VEGF designed for ocular use, became the first and only U.S. Food and Drug Administration–approved medical therapy for DME and the first approved treatment in over 25 years. This approval was based on strong preclinical data followed by numerous clinical trials that demonstrate an essential role of VEGF in vascular permeability and angiogenesis in both normal physiology and disease pathology. In this Perspective, we will examine the experimental studies and scientific data that aided in the success of the development of therapies targeting VEGF and consider how these approaches may inform the development of future therapeutics for diabetic eye disease. A multipoint model is proposed, based on well-established drug development principles, with the goal of improving the success of clinical drug development. This model suggests that to provide a validated preclinical target, investigators should demonstrate the following: the role of the target in normal physiology, a causal link to disease pathogenesis, correlation to human disease, and the ability to elicit clinically relevant improvements of disease phenotypes in animal models with multiple, chemically diverse interventions. This model will provide a framework to validate the current preclinical targets and identify novel targets to improve drug development success for DR. PMID:23704522

  17. Cellular carbohydrate components in human, rabbit and rat lacrimal gland. Studies using fluorescein and peroxidase labelled lectins.

    PubMed

    Ahmed, A; Grierson, I

    1989-01-01

    Orbital lacrimal glands from adult male and female rabbits, rats and humans were examined for the presence of intracellular receptors of four lectins: concanavalin-A agglutinin, lutus tetragonolobus agglutinin, ricinus comunis-60 agglutinin and wheat-germ agglutinin using fluorescein-conjugated lectin and peroxidase labelling methods for fluorescence and electron microscopy, respectively. Lectins were used as specific probes to detect carbohydrate moiety of the lacrimal gland. The pattern of labelling with the lectins suggests that N-acetyl-glucosamine, N-acetyl-D-galactosamine, D-galactose, D-mannose, sialic acid and L-fucose are contained in the lacrimal gland of the three species. The significance of these findings is discussed. PMID:2920911

  18. Common-path Fourier domain optical coherence tomography of irradiated human skin and ventilated isolated rabbit lungs

    NASA Astrophysics Data System (ADS)

    Popp, A.; Wendel, M.; Knels, L.; Knuschke, P.; Mehner, M.; Koch, T.; Boller, D.; Koch, P.; Koch, E.

    2005-08-01

    A compact common path Fourier domain optical coherence tomography (FD-OCT) system based on a broadband superluminescence diode is used for biomedical imaging. The epidermal thickening of human skin after exposure to ultraviolet radiation is measured to proof the feasibility of FD-OCT for future substitution of invasive biopsies in a long term study on natural UV skin protection. The FD-OCT system is also used for imaging lung parenchyma. FD-OCT images of a formalin fixated lung show the same alveolar structure as scanning electron microscopy images. In the ventilated and blood-free perfused isolated rabbit lung FD-OCT is used for real-time cross-sectional image capture of alveolar mechanics throughout tidal ventilation. The alveolar mechanics changing from alternating recruitment-derecruitment at zero positive end-expiratory pressure (PEEP) to persistent recruitment after applying a PEEP of 5 cm H2O is observed in the OCT images.

  19. Novel bocaparvoviruses in rabbits.

    PubMed

    Lanave, G; Martella, V; Farkas, S L; Marton, S; Fehér, E; Bodnar, L; Lavazza, A; Decaro, N; Buonavoglia, C; Bányai, K

    2015-11-01

    Bocaparvovirus is a newly established genus within the family Parvoviridae and has been identified as a possible cause of enteric, respiratory, reproductive/neonatal and neurological disease in humans and several animal species. In this study, metagenomic analysis was used to identify and characterise a novel bocaparvovirus in the faeces of rabbits with enteric disease. To assess the prevalence of the novel virus, rectal swabs and faecal samples obtained from rabbits with and without diarrhoea were screened with a specific PCR assay. The complete genome sequence of the novel parvovirus was reconstructed. The virus was distantly related to other bocaparvoviruses; the three ORFs shared 53%, 53% and 50% nucleotide identity, respectively, to homologous genes of porcine bocaparvoviruses. The virus was detected in 8/29 (28%) and 16/95 (17%) samples of rabbits with and without diarrhoea, respectively. Sequencing of the capsid protein fragment targeted by the diagnostic PCR identified two distinct bocaparvovirus populations/sub-types, with 91.7-94.5% nucleotide identity to each other. Including these novel parvoviruses in diagnostic algorithms of rabbit diseases might help inform their potential pathogenic role and impact on rabbit production and the virological profiles of laboratory rabbits. PMID:26383859

  20. Recombinant saphenous vein 5-HT1B receptors of the rabbit: comparative pharmacology with human 5-HT1B receptors.

    PubMed

    Wurch, T; Palmier, C; Colpaert, F C; Pauwels, P J

    1997-01-01

    1. The rabbit recombinant saphenous vein 5-hydroxytryptamine1B (r 5-HT1B) receptor stably transfected in rat C6-glial cells was characterized by measuring adenosine 3':5'-cyclic monophosphate (cycle AMP) formation upon exposure to various 5-HT receptor ligands. The effects of agonists and antagonists were compared with their effects determined previously at the human cloned 5-HT1B (h 5-HT1B) receptor under similar experimental conditions. 2. Intact C6-glial cells expressing rb HT1B receptors exhibited [3H]-5-carboxamidotryptamine (5-CT) binding sites with a Kd of 0.80 +/- 0.13 nM and a Bmax between 225 to 570 fmol mg-1 protein. The binding affinities of a series of 5-HT receptor ligands determined in a membrane preparation with [3H]-5-CT or [3H]-N-[4-methoxy-3-(4-methylpiperazin-1-yl)phenyl]-3-methyl-4-(-4 -pyridyl) benzamide (GR 125,743) were similar. With the exception of ketanserin, ligand affinities were comparable to those determined at the clones h 5-HT1B receptor site. 3. rb 5-HT1B receptors were negatively coupled to cyclic AMP formation upon stimulation with 5-HT agonists. Of the several 5-HT agonists tested, 5-CT was the most potent, the potency rank order being: 5-CT > 5-HT > zolmitriptan > naratriptan > rizatriptan > sumatriptan > R (+)-8-(hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT). The maximal responses of these agonists were similar to those induced by 5-HT. The potency of these agonists showed a positive correlation (r2 = 0.87; P < 0.002) with their potency at the cloned h 5-HT1B receptor subtype. 4. 2'-Methyl-4-(5-methyl-[1,2,4]oxadiazol-3-yl)-biphenyl-4-carboxylic acid [4-methoxy-e-(4-methyl-piperazin-1-yl)-phenyl]-amide (GR 127,935), methiothepin and ketanserin each behaved as silent, competitive antagonists at rb 5HT1B receptors; pKB values were 8.41, 8.32 and 7.05, respectively when naratriptan was used as an agonist. These estimates accorded with their binding affinities and the potencies found on 5-HT and/or sumatriptan

  1. High-level expression of a novel recombinant human plasminogen activator (rhPA) in the milk of transgenic rabbits and its thrombolytic bioactivity in vitro.

    PubMed

    Song, Shaozheng; Ge, Xin; Cheng, Yaobin; Lu, Rui; Zhang, Ting; Yu, Baoli; Ji, Xueqiao; Qi, Zhengqiang; Rong, Yao; Yuan, Yuguo; Cheng, Yong

    2016-08-01

    The human tissue-type plasminogen activator (tPA) is a key kinase of fibrinolysis that plays an important role in dissolving fibrin clots to promote thrombolysis. The recombinant human plasminogen activator (rhPA) has more thrombolytic advantages than the wild type tPA. To increase the half-life and thrombolytic activity of tPA, a mutant containing only the essential K2 fibrin-binding and P activating plasminogen domains of the wild type tPA was cloned. This fragment was then inserted into goat β-casein regulatory sequences. Then, a mammary gland-specific expression vector, PCL25/rhPA, was constructed, and the transgenic rabbits were generated. In this study, 18 live transgenic founders (12♀, 6♂) were generated using pronuclear microinjection. Six transgenic rabbits were obtained, and the expression levels of rhPA in the milk had a range of 15.2-630 µg/ml. A fibrin agarose plate assay of rhPA showed that it had strong thrombolytic bioactivity in vitro, and the highest specific activity was >360 (360 times more than that of alteplase). The results indicated that the rhPA containing only the K2 and P domains is efficiently expressed with higher thrombolytic bioactivity in the milk of transgenic rabbits. Our study also demonstrated a new method for the large-scale production of clinically relevant recombinant pharmaceutical proteins in the mammary glands of transgenic rabbits. PMID:27230577

  2. The effect of rabbit antithymocyte globulin on human mesenchymal stem cells.

    PubMed

    Franquesa, Marcella; Baan, Carla C; Korevaar, Sander S; Engela, Anja U; Roemeling-van Rhijn, Marieke; Weimar, Willem; Betjes, Michiel G H; Grinyo, Josep M; Hoogduijn, Martin J

    2013-06-01

    Mesenchymal stem cells (MSCs) possess immunomodulatory properties which are of key interest for their application in autoimmunity and transplantation. In transplantation, administration of MSCs has shown promising results in preclinical models and has recently moved to clinical trials. Therefore, it is important to study the interactions between MSCs and immunosuppressive drugs currently used in transplantation. We aimed to analyze the effect of rabbit antithymocyte globulin (rATG) MSCs. MSCs were obtained from perirenal fat of kidney donors and exposed to ranging doses of rATG (Thymoglobulin(®) , Genzyme; 0.5-100 μg/ml). Binding of rATG, effects on viability and susceptibility to be killed by cytotoxic lymphocytes as well as effects on their immunosuppressive potential of MSCs were tested. rATG binds dose-dependently to MSCs. This binding was associated with slightly impaired viability after 48 and 72 h when compared with nonexposed MSCs. In contrast to nontreated MSCs, rATG preexposed MSCs were susceptible to be lysed by cytokine-activated CD8(+) cytotoxic cells and NKT cells. The capacity of MSCs to suppress the proliferation of anti-CD3/CD28 activated CD4 and CD8 T cells were reduced by the presence of rATG in the culture. rATG reduces the viability and antiproliferative capacity of MSCs in a dose-dependent manner and converts them into targets for CD8 T cells and NKT cell lysis. PMID:23682671

  3. Human monoclonal antibody AVP-21D9 to protective antigen reduces dissemination of the Bacillus anthracis Ames strain from the lungs in a rabbit model.

    PubMed

    Peterson, Johnny W; Comer, Jason E; Baze, Wallace B; Noffsinger, David M; Wenglikowski, Autumn; Walberg, Kristin G; Hardcastle, Jason; Pawlik, Jennifer; Bush, Kathryn; Taormina, Joanna; Moen, Scott; Thomas, John; Chatuev, Bagram M; Sower, Laurie; Chopra, Ashok K; Stanberry, Lawrence R; Sawada, Ritsuko; Scholz, Wolfgang W; Sircar, Jagadish

    2007-07-01

    Dutch-belted and New Zealand White rabbits were passively immunized with AVP-21D9, a human monoclonal antibody to protective antigen (PA), at the time of Bacillus anthracis spore challenge using either nasal instillation or aerosol challenge techniques. AVP-21D9 (10 mg/kg) completely protected both rabbit strains against lethal infection with Bacillus anthracis Ames spores, regardless of the inoculation method. Further, all but one of the passively immunized animals (23/24) were completely resistant to rechallenge with spores by either respiratory challenge method at 5 weeks after primary challenge. Analysis of the sera at 5 weeks after primary challenge showed that residual human anti-PA levels decreased by 85 to 95%, but low titers of rabbit-specific anti-PA titers were also measured. Both sources of anti-PA could have contributed to protection from rechallenge. In a subsequent study, bacteriological and histopathology analyses revealed that B. anthracis disseminated to the bloodstream in some naïve animals as early as 24 h postchallenge and increased in frequency with time. AVP-21D9 significantly reduced the dissemination of the bacteria to the bloodstream and to various organs following infection. Examination of tissue sections from infected control animals, stained with hematoxylin-eosin and the Gram stain, showed edema and/or hemorrhage in the lungs and the presence of bacteria in mediastinal lymph nodes, with necrosis and inflammation. Tissue sections from infected rabbits dosed with AVP-21D9 appeared comparable to corresponding tissues from uninfected animals despite lethal challenge with B. anthracis Ames spores. Concomitant treatment with AVP-21D9 at the time of challenge conferred complete protection in the rabbit inhalation anthrax model. Early treatment increased the efficacy progressively and in a dose-dependent manner. Thus, AVP-21D9 could offer an adjunct or alternative clinical treatment regimen against inhalation anthrax. PMID:17452469

  4. Human Monoclonal Antibody AVP-21D9 to Protective Antigen Reduces Dissemination of the Bacillus anthracis Ames Strain from the Lungs in a Rabbit Model▿

    PubMed Central

    Peterson, Johnny W.; Comer, Jason E.; Baze, Wallace B.; Noffsinger, David M.; Wenglikowski, Autumn; Walberg, Kristin G.; Hardcastle, Jason; Pawlik, Jennifer; Bush, Kathryn; Taormina, Joanna; Moen, Scott; Thomas, John; Chatuev, Bagram M.; Sower, Laurie; Chopra, Ashok K.; Stanberry, Lawrence R.; Sawada, Ritsuko; Scholz, Wolfgang W.; Sircar, Jagadish

    2007-01-01

    Dutch-belted and New Zealand White rabbits were passively immunized with AVP-21D9, a human monoclonal antibody to protective antigen (PA), at the time of Bacillus anthracis spore challenge using either nasal instillation or aerosol challenge techniques. AVP-21D9 (10 mg/kg) completely protected both rabbit strains against lethal infection with Bacillus anthracis Ames spores, regardless of the inoculation method. Further, all but one of the passively immunized animals (23/24) were completely resistant to rechallenge with spores by either respiratory challenge method at 5 weeks after primary challenge. Analysis of the sera at 5 weeks after primary challenge showed that residual human anti-PA levels decreased by 85 to 95%, but low titers of rabbit-specific anti-PA titers were also measured. Both sources of anti-PA could have contributed to protection from rechallenge. In a subsequent study, bacteriological and histopathology analyses revealed that B. anthracis disseminated to the bloodstream in some naïve animals as early as 24 h postchallenge and increased in frequency with time. AVP-21D9 significantly reduced the dissemination of the bacteria to the bloodstream and to various organs following infection. Examination of tissue sections from infected control animals, stained with hematoxylin-eosin and the Gram stain, showed edema and/or hemorrhage in the lungs and the presence of bacteria in mediastinal lymph nodes, with necrosis and inflammation. Tissue sections from infected rabbits dosed with AVP-21D9 appeared comparable to corresponding tissues from uninfected animals despite lethal challenge with B. anthracis Ames spores. Concomitant treatment with AVP-21D9 at the time of challenge conferred complete protection in the rabbit inhalation anthrax model. Early treatment increased the efficacy progressively and in a dose-dependent manner. Thus, AVP-21D9 could offer an adjunct or alternative clinical treatment regimen against inhalation anthrax. PMID:17452469

  5. Expression of human factor IX in rabbit hepatocytes by retrovirus-mediated gene transfer: Potential for gene therapy of hemophilia B

    SciTech Connect

    Thompson, A.R. Puget Sound Blood Center, Seattle, WA ); Darlington, G. ); Armentano, D.; Woo, S.L.C.

    1990-08-01

    Hemophilia B (Christmas disease) is a chromosome X-linked blood clotting disorder which results when factor IX is deficient or functionally defective. The enzyme is synthesized in the liver, and the existence of animal models for this genetic disease will permit the development of somatic gene therapy protocols aimed at transfer of the functional gene into the liver. The authors report the construction of an N2-based recombinant retroviral vector, NCMVFIX, for efficient transfer and expression of human factor IX cDNA in primary rabbit hepatocytes. In this construct the human cytomegalovirus immediate early promoter directs the expression of factor IX. Hepatocytes were isolated from 3-week-old New Zealand White rabbits, infected with the recombinant virus, and analyzed for secretion of active factor IX. The infected rabbit hepatocytes produced human factor IX that is indistinguishable from enzyme derived from normal human plasma. The recombinant protein is sufficiently {gamma}-carboxylated and is functionally active in clotting assays. These results establish the feasibility of using infected hepatocytes for the expression of this protein and are a step toward the goal of correcting hemophilia B by hepatic gene transfer.

  6. Prophylaxis With a Middle East Respiratory Syndrome Coronavirus (MERS-CoV)-Specific Human Monoclonal Antibody Protects Rabbits From MERS-CoV Infection.

    PubMed

    Houser, Katherine V; Gretebeck, Lisa; Ying, Tianlei; Wang, Yanping; Vogel, Leatrice; Lamirande, Elaine W; Bock, Kevin W; Moore, Ian N; Dimitrov, Dimiter S; Subbarao, Kanta

    2016-05-15

    With >1600 documented human infections with Middle East respiratory syndrome coronavirus (MERS-CoV) and a case fatality rate of approximately 36%, medical countermeasures are needed to prevent and limit the disease. We examined the in vivo efficacy of the human monoclonal antibody m336, which has high neutralizing activity against MERS-CoV in vitro. m336 was administered to rabbits intravenously or intranasally before infection with MERS-CoV. Prophylaxis with m336 resulted in a reduction of pulmonary viral RNA titers by 40-9000-fold, compared with an irrelevant control antibody with little to no inflammation or viral antigen detected. This protection in rabbits supports further clinical development of m336. PMID:26941283

  7. Pathogenicity of rotavirus in rabbits.

    PubMed Central

    Thouless, M E; DiGiacomo, R F; Deeb, B J; Howard, H

    1988-01-01

    The role of rotavirus in diarrheal disease of rabbits was investigated, and a model for human rotavirus infection was established. Orogastric inoculation of 8- and 12-week-old New Zealand White rabbits with a rabbit strain of rotavirus (L:ALA:84) resulted in fecal shedding of virus for 6 to 8 days from 2 to 5 days after inoculation. Most rabbits exhibited diarrhea, coincident with the onset of viral shedding, which persisted for 2 to 4 days. Diarrhea was characterized by soft or fluid stools and fecal staining of the perineum. Inoculation of 3-week-old rabbits resulted in a briefer period of viral shedding and diarrhea of a milder nature. Histopathologic examination during the period of viral shedding revealed a mild, nonsuppurative enteritis. Inoculated rabbits exhibited antibodies in serum to rotavirus by enzyme-linked immunosorbent assay. Sham-inoculated or uninoculated rabbits maintained in the same cage or the same room with inoculated rabbits acquired rotavirus infection. The mild diarrheal disease which resulted with a rotavirus isolate from severe field cases suggests that cofactors were involved. Images PMID:2838507

  8. Ultrathin, Stretchable, Multiplexing pH Sensor Arrays on Biomedical Devices With Demonstrations on Rabbit and Human Hearts Undergoing Ischemia

    PubMed Central

    Chung, Hyun-Joong; Sulkin, Matthew S.; Kim, Jong-Seon; Goudeseune, Camille; Chao, Hsin-Yun; Song, Joseph W.; Yang, Sang Yoon; Hsu, Yung-Yu; Ghaffari, Roozbeh

    2014-01-01

    Stable pH is an established biomarker of health, relevant to all tissues of the body, including the heart. Clinical monitoring of pH in a practical manner, with high spatiotemporal resolution, is particularly difficult in organs such as the heart due to its soft mechanics, curvilinear geometry, heterogeneous surfaces and continuous, complex rhythmic motion. The results presented here illustrate that advanced strategies in materials assembly and electrochemical growth can yield interconnected arrays of miniaturized IrOx pH sensors encapsulated in thin, low-modulus elastomers to yield conformal monitoring systems capable of non-invasive measurements on the surface of the beating heart. A thirty channel custom data acquisition system enables spatiotemporal pH mapping with a single potentiostat. In-vitro testing reveals super-Nernstian sensitivity with excellent uniformity (69.9 ± 2.2 mV/pH), linear response to temperature (−1.6 mV/°C), and minimal influence of extracellular ions (< 3.5 mV). Device examples include sensor arrays on balloon catheters and on skin-like stretchable membranes. Real-time measurement of pH on the surfaces of explanted rabbit hearts and a donated human heart during protocols of ischemia-reperfusion illustrate some of the capabilities. Envisioned applications range from devices for biological research, to surgical tools and long-term implants. PMID:23868871

  9. Replication needed to detect alterations in the composition of rodent, rabbit, or human testes via volume density approaches.

    PubMed

    Berndtson, William E

    2010-01-01

    Sperm production is an important variable affecting the reproductive capacity of men and other male mammals. Because spermatogenesis is highly susceptible to disruption, volume density techniques that enable the composition of testicular tissue to be characterized or sperm production rates to be quantified are used extensively to assess potential impacts of known or suspected reproductive toxins, the safety of proposed human or animal drugs, and basic studies on spermatogenesis in normal individuals. The number of subjects used per treatment group for such studies has been variable. However, the power and sensitivity of any experiment is dependent on the inherent variability associated with the end point(s) of interest and the number of replicates (ie, animals or men per treatment group) employed per treatment group. Because the reliability of one's experimental outcome should be of utmost consideration, it is important to characterize the typical levels of inherent variability associated with one's chosen end point(s) and to answer the question: how many subjects are required per treatment group to provide an experiment with a given power and sensitivity for detecting actual treatment effects? This study was undertaken to 1) characterize the inherent variability associated with the volume density of several testicular components in rodents, rabbits, and humans and among cell numbers derived from volume density data and 2) identify the approximate number of replicates that would be required to provide future studies of predictable power and sensitivity for which data were to be generated via the volume density approach. Replication requirements differed, sometimes by several orders of magnitude, among these species and among end points within a single species. In addition, for many of these species and end points, the number of replicates necessary to ensure modest power and sensitivity for detecting treatment differences exceeded that used in most investigations

  10. Pharmacokinetics of 2-ethyl-1,3-hexanediol. III. In vitro skin penetration comparisons using the excised skin of humans, rats, and rabbits.

    PubMed

    Frantz, S W; Ballantyne, B; Beskitt, J L; Tallant, M J; Greco, R J

    1995-11-01

    Excised skin from Fischer 344 rats, New Zealand White rabbits, and human females (obtained from mammoplasty patients) were compared for their in vitro skin penetration potential with 2-[14C]-ethyl-1,3-hexanediol (EHD). EHD was applied as both an undiluted dose and a 3% v/v aqueous dose using a flowthrough skin penetration chamber design and was analyzed over 0-6 hr. The undiluted dose was equivalent to a 150 mg/kg dose used in vivo with rats (Frantz et al., Drug Metab. Dispos. 20(1), 6-18, 1992), but normalized on a per cm2 surface area basis, and applied under occluded conditions (covered as for in vivo studies). Undiluted applications of EHD did not substantially penetrate skin, with effluent recoveries of approximately 0.9% of the applied dose for human skin, 2-4% for rat skin, and 3-6% for rabbit skin. By comparison, nonoccluded human skin showed lower effluent radioactivity (0.6%), which was attributed to EHD evaporation from skin. With undiluted EHD, approximately 97% of the recovered 14C was an unabsorbed dose for human skin, with 94% for rat skin and 85% for rabbit skin (expressed as a percentage of the recovered dose). Based on HPLC analysis of effluent samples, 99-100% of the undiluted [14C]EHD penetrated rat, rabbit, and human skin in the unmetabolized form. In contrast, approximately 5% of the applied aqueous dose was recovered in the effluents for human skin, while 6-9% appeared in effluents for rat skin; rabbit skin was not evaluated for aqueous doses. The fraction of unabsorbed aqueous EHD dose totaled 53% of the applied dose for human skin and 63% for rat skin. Evaporative loss of undiluted [14C]EHD was also measured (captured on activated charcoal) in separate experiments and compared with a known standard chemical, N,N[14C]diethyl-m-toluamide (DEET). Evaporation of EHD was clearly a competing factor with penetration, particularly for human skin preparations, and evaporative losses were similar to those seen in previous studies. Penetration of skin

  11. Antigen dose escalation study of a VEGF-based therapeutic cancer vaccine in non human primates.

    PubMed

    Morera, Yanelys; Bequet-Romero, Mónica; Ayala, Marta; Pérez, Pedro Puente; Castro, Jorge; Sánchez, Javier; Alba, José Suárez; Ancízar, Julio; Cosme, Karelia; Gavilondo, Jorge V

    2012-01-01

    CIGB-247 is a cancer therapeutic, based on recombinant modified human vascular endothelial growth factor (VEGF) as antigen, in combination with the oil free adjuvant VSSP (very small sized proteoliposomes of Neisseria meningitidis outer membrane). Our previous experimental studies in mice with CIGB-247 have shown that the vaccine has both anti-tumoral and anti-metastatic activity, and produces both antibodies that block VEGF-VEGF receptor interaction, and a specific T-cell cytotoxic response against tumor cells. CIGB-247, with an antigen dose of 100 μg, has been characterized by an excellent safety profile in mice, rats, rabbits, and non human primates. In this article we extend the immunogenicity and safety studies of CIGB-247 in non human primates, scaling the antigen dose from 100 μg to 200 and 400 μg/vaccination. Our results indicate that such dose escalation did not affect animal behavior, clinical status, and blood parameters and biochemistry. Also, vaccination did not interfere with skin deep skin wound healing. Anti-VEGF IgG antibodies and specific T-cell mediated responses were documented at all three studied doses. Antigen dose apparently did not determine differences in maximum antibody titer during the 8 weekly immunization induction phase, or the subsequent increase in antibodies seen for monthly boosters delivered afterwards. Higher antigen doses had a positive influence in antibody titer maintenance, after cessation of immunizations. Boosters were important to achieve maximum antibody VEGF blocking activity, and specific T-cell responses in all individuals. Purified IgG from CIGB-247 immunized monkey sera was able to impair proliferation and formation of capillary-like structures in Matrigel, for HMEC cells in culture. Altogether, these results support the further clinical development of the CIGB-247 therapeutic cancer vaccine, and inform on the potential mechanisms involved in its effect. PMID:22075086

  12. Functional properties of DENV EDIII‑reactive antibodies in human DENV‑1‑infected sera and rabbit antiserum to EDIII.

    PubMed

    Chen, Jing; Wen, Kun; Li, Xiao-Quan; Yi, Hai-Su; Ding, Xi-Xia; Huang, Yan-Fen; Pan, Yu-Xian; Hu, Dong-Mei; Di, Biao; Che, Xiao-Yan; Fu, Ning

    2016-08-01

    The envelope domain III (EDIII) of the dengue virus (DENV) has been confirmed to be involved in receptor binding. It is the target of specific neutralizing antibodies, and is considered to be a promising subunit dengue vaccine candidate. However, several recent studies have shown that anti‑EDIII antibodies contribute little to the neutralizing or enhancing ability of human DENV‑infected serum. The present study involved an analysis of the neutralization and antibody‑dependent enhancement (ADE) activities of EDIII‑reactive antibodies in human convalescent sera from patients with primary DENV‑1 infection and rabbit antiserum immunized with recombinant DENV‑1 EDIII protein. The results indicated that serum neutralization was not associated with titres of EDIII‑binding antibodies in the human DENV‑1‑infected sera. The depletion of anti‑EDIII antibodies from these serum samples revealed that the anti‑EDIII antibodies of the patients contributed little to neutralization and ADE. However, the EDIII‑reactive antibodies from the rabbit antiserum exhibited protective abilities of neutralization at a high dilution (~1:50,000) and ADE at a low dilution (~1:5,000) for the homotypic DENV infection. Notably, the rabbit antiserum displayed ADE activity only at a dilution of 1:40 for the heterotypic virus infection, which suggests that EDIII‑reactive antibodies may be safe in secondary infection with heterotypic viruses. These results suggest that DENV EDIII is not the predominant antigen of the DENV infection process; however, purified or recombinant DENV EDIII may be used as a subunit vaccine to provoke an effective and safe antibody response. PMID:27357403

  13. 2-/sup 14/C-1-Allyl-3,5-diethyl-6-chlorouracil I: Synthesis, absorption in human skin, excretion, distribution, and metabolism in rats and rabbits

    SciTech Connect

    Kaul, R.; Hempel, B.; Kiefer, G.

    1982-08-01

    With /sup 14/C-potassium cyanate as the starting material, 2-/sup 14/C-1-allyl-3,5-diethyl-6-chlorouracil was synthesized for in vitro and in vivo absorption studies in human skin and for metabolic studies in rats and rabbits. The radioactivity in the horny layer, epidermis, and dermis of the human skin was determined after different intervals of time, and the radioactivity excreted in the urine was measured by collecting samples for 5 days from a patient and also under occlusion conditions. Almost 90% of the radioactivity remained on the surface and approximately 6.28% penetrated and was systemically absorbed. Over a 5-day period, a total of 3.25% was excreted. Almost 3% was systemically absorbed and cumulated in the system. After intraperitoneal application in male and female rats, most of the radioactivity was excreted in the feces and urine, with female rats excreting more in the urine than male rats. The radioactivity rose in the organs in the first 3 hr and then decreased. At the end of 144 hr, no appreciable radioactivity could be found in the organs and tissues, except in the carcass where the cumulation was maximum (1%). After intravenous injection in rabbits, most of the radioactivity (80%) was excreted in the urine and only 4% in the feces. At the end of 96 hr, approximately 3% was cumulated in the body. The drug was quantitatively metabolized in both rats and rabbits: Metabolite 1 (70-85%), Metabolite 2 (10-15%), Metabolite 3 (5-10%), and Metabolite 4 (0.3%).

  14. Sensitivity of K1-Encapsulated Escherichia coli to Killing by the Bactericidal/Permeability-Increasing Protein of Rabbit and Human Neutrophils

    PubMed Central

    Weiss, Jerrold; Victor, Michael; Cross, Alan S.; Elsbach, Peter

    1982-01-01

    The presence of K1 capsular polysaccharides increases the resistance of Escherichia coli to killing by serum and phagocytosis by polymorphonuclear leukocytes (PMNs). To determine whether K1 capsule impedes the action of intracellular bactericidal systems of PMNs, we compared the sensitivity of several K1-encapsulated and non-encapsulated strains of E. coli to killing by the bactericidal/permeability-increasing protein (BPI) isolated from rabbit and human PMNs. BPI appears to be the principal bactericidal agent of PMNs toward E. coli and other gram-negative bacteria (Weiss et al., J. Clin. Invest. 69:959-970, 1982). The presence of K1 capsule was monitored by sensitivity to K1-specific bacteriophages. The non-encapsulated strains used represent both random bacteremic isolates and non-encapsulated derivatives of K1-encapsulated strains obtained by selection for resistance to K1-specific phages. We found little or no difference in the sensitivity of K1-encapsulated and non-encapsulated E. coli to killing by neutralized acid extracts of rabbit PMNs. Bacterial killing by these crude fractions can be attributed to the action of BPI because: (i) bacterial killing was blocked by immune (anti-BPI) immunoglobulin but not by preimmune immunoglobulin and (ii) comparison of the dose-response curves of bacterial killing by crude extracts and by purified BPI showed that the bactericidal activity of crude fractions corresponded closely to the BPI content. Human and rabbit BPIs exhibited similar bactericidal potency toward K1-encapsulated E. coli; i.e., <5 μg of either protein killed >90% of 2.5 × 107 bacteria. Thus, the potent bactericidal action of BPI toward E. coli is not impeded by K1 capsule, suggesting that the virulence of K1-encapsulated E. coli is a consequence of extracellular survival but not of resistance to intracellular killing. PMID:6759406

  15. Aflibercept, bevacizumab and ranibizumab prevent glucose-induced damage in human retinal pericytes in vitro, through a PLA2/COX-2/VEGF-A pathway.

    PubMed

    Giurdanella, Giovanni; Anfuso, Carmelina Daniela; Olivieri, Melania; Lupo, Gabriella; Caporarello, Nunzia; Eandi, Chiara M; Drago, Filippo; Bucolo, Claudio; Salomone, Salvatore

    2015-08-01

    Diabetic retinopathy, a major cause of vision loss, is currently treated with anti-VEGF agents. Here we tested two hypotheses: (i) high glucose damages retinal pericytes, the cell layer surrounding endothelial cells, via VEGF induction, which may be counteracted by anti-VEGFs and (ii) activation of PLA2/COX-2 pathway by high glucose might be upstream and/or downstream of VEGF in perycites, as previously observed in endothelial cells. Human retinal pericytes were treated with high glucose (25mM) for 48h and/or anti-VEGFs (40μg/ml aflibercept, 25μg/ml bevacizumab, 10μg/ml ranibizumab). All anti-VEGFs significantly prevented high glucose-induced cell damage (assessed by LDH release) and improved cell viability (assessed by MTT and Evans blue). High glucose-induced VEGF-A expression, as detected both at mRNA (qPCR) and protein (ELISA) level, while receptor (VEGFR1 and VEGFR2) expression, detected in control condition, was unaffected by treatments. High glucose induced also activation of PLA2/COX-2 pathway, as revealed by increased phosphorylation of cPLA2, COX-2 expression and PGE2 release. Treatment with cPLA2 (50μM AACOCF3) and COX-2 (5μM NS-392) inhibitors prevented both cell damage and VEGF-A induced by high glucose. Finally, challenge with exogenous VEGF-A (10ng/ml) induced VEGF-A expression, while anti-VEGFs reduced VEGF-A expression induced by either high glucose or exogenous VEGF-A. These data indicate that high glucose directly damages pericytes through activation of PLA2/COX-2/VEGF-A pathway. Furthermore, a kind of feed-forward loop between cPLA2/COX-2/PG axis and VEGF appears to operate in this system. Thus, anti-VEGFs afford protection of pericytes from high glucose by inhibiting this loop. PMID:26056075

  16. Spontaneous bilateral avulsion fracture of the tuberositas tibiae in a New Zealand White rabbit - a counterpart to Osgood-Schlatter disease in humans?

    PubMed

    Nehrbass, D; Arens, D; Zeiter, S

    2015-02-01

    The first reported case describing a spontaneous bilateral avulsion fracture of the tuberositas tibiae in a New Zealand White rabbit is presented. So far in animals, this condition has been only described in dogs and horses. In humans, this condition is also called Osgood-Schlatter disease (OSD) or syndrome, traction apophysitis of the tibial tubercle (ATT) or patellar tendon enthesopathy of the tibial tuberosity respectively. It is mainly seen in young adolescents coinciding with periods of growth spurts. In humans, its pathogenesis is believed to be caused by repetitive tendon/muscle strain at the insertion of the patellar tendon to the immature tibial tuberosity, which has its own secondary ossification center. Morphologically this case is characterized by bilateral chronic avulsion with incomplete separation of the tuberositas tibae, and proximal dislocation of the patella (patella alta). Despite these marked pathological changes, the animal was clinically without findings. Nevertheless, this case emphasizes the need for thorough clinical and radiological examination of rabbits intended for preclinical research studies prior to study begin, especially in orthopedic research. PMID:25435475

  17. Monoclonal antibodies directed against major histocompatibility complex antigens bind to the surface of Treponema pallidum isolated from infected rabbits or humans.

    PubMed

    Marchitto, K S; Kindt, T J; Norgard, M V

    1986-09-01

    Evidence is presented for the association of class I major histocompatibility complex (MHC) antigens with the surface of Treponema pallidum during infection. A monoclonal antibody (IgG2a) directed against a murine H-2Kb epitope of public specificity reacted with the cell surface of T. pallidum, as assayed by the binding of protein A-colloidal gold in immunoelectron microscopy. Monoclonal antibodies directed against class I rabbit MHC antigens also reacted in immunofluorescence assays with material on the surface of rabbit-cultivated T. pallidum. In addition, impression smears of human syphilitic genital ulcers that were darkfield-positive for the presence of spirochetes were tested in immunofluorescence assays with monoclonal antibodies directed against human MHC antigens; antibody directed against HLA-ABC (class I) was reactive whereas antibody directed against HLA-DR (class II) was nonreactive. Results of the study suggest that the association of host-derived class I MHC antigens or molecular mimicry may play a role in T. pallidum evasion of host immune defenses. PMID:2428519

  18. The cottontail rabbits of Virginia

    USGS Publications Warehouse

    Llewellyn, L.M.; Handley, C.O.

    1945-01-01

    Five races of cottontail rabbits belonging to three species occur in Virginia. One of them, the Mearns cottontail (Sylvilagus floridanus mearnsi), is reported here for the first time. It occurs in six southwestern counties of the state, while the eastern cottontail (S. f. mallurus) occurs in the remainder of the state with the exception of Smith and Fishermans islands off the eastern coast of Cape Charles, where it is replaced by Hitchens cottontail (S. f. hitchensi). The New England cottontail (S. transitionalis) is found on the higher mountain peaks, above 3000 feet, and the swamp rabbit (S. palustris) occurs in the Dismal Swamp region of southeastern Virginia.....The height of the breeding season for the eastern cottontail in Virginia is March and April, but breeding continues through the entire year except in December and January. The average litter size based on embryo counts was 4.7. The sex ratio of 234 specimens from all parts of the state, taken mostly in the December to February period, was 53 males to 47 females. That of a group of 145 rabbits live-trapped at Blacksburg during February and Marchwas 58 males to 42 females. The figures show that males are more active than females during the winter months, and therefore are more easily taken then....In transplanting cottontails from one section of the state to another, it is recommended that only cottontails of the same race as those originally present in the region being restocked be released there....Tularemia is not a common disease among rabbits in Virginia, but the rabbit ticks are often carriers of the disease and may transmit it to rabbits. Rabbit ticks are also found to be carriers of Rocky Mountain fever and American Q. fever. After the ticks drop off the rabbits to hibernate in the ground, which is likely to occur during mid-winter in Virginia, there is relatively little danger of humans contracting tularemia by contact with rabbits. Present laws in Virginia which prohibit rabbit hunting until the

  19. Immunization of Rabbits with Highly Purified, Soluble, Trimeric Human Immunodeficiency Virus Type 1 Envelope Glycoprotein Induces a Vigorous B Cell Response and Broadly Cross-Reactive Neutralization

    PubMed Central

    Quinnan, Gerald V.; Onabajo, Olusegun; Zhang, Pengfei; Yan, Lianying; Mattapallil, Joseph J.; Zhang, Zhiqiang; Dong, Ming; Lu, Min; Montefiori, David; LaBranche, Celia; Broder, Christopher C.

    2014-01-01

    Previously we described induction of cross-reactive HIV-1 neutralizing antibody responses in rabbits using a soluble HIV-1 gp140 envelope glycoprotein (Env) in an adjuvant containing monophosphoryl lipid A (MPL) and QS21 (AS02A). Here, we compared different forms of the same HIV-1 strain R2 Env for antigenic and biophysical characteristics, and in rabbits characterized the extent of B cell induction for specific antibody expression and secretion and neutralizing responses. The forms of this Env that were produced in and purified from stably transformed 293T cells included a primarily dimeric gp140, a trimeric gp140 appended to a GCN4 trimerization domain (gp140-GCN4), gp140-GCN4 with a 15 amino acid flexible linker between the gp120 and gp41 ectodomain (gp140-GCN4-L), also trimeric, and a gp140 with the flexible linker purified from cell culture supernatants as either dimer (gp140-L(D)) or monomer (gp140-L(M)). Multimeric states of the Env proteins were assessed by native gel electrophoresis and analytical ultracentrifugation. The different forms of gp140 bound broadly cross-reactive neutralizing (BCN) human monoclonal antibodies (mAbs) similarly in ELISA and immunoprecipitation assays. All Envs bound CD4i mAbs in the presence and absence of sCD4, as reported for the R2 Env. Weak neutralization of some strains of HIV-1 was seen after two additional doses in AS02A. Rabbits that were given a seventh dose of gp140-GCN4-L developed BCN responses that were weak to moderate, similar to our previous report. The specificity of these responses did not appear similar to that of any of the known BCN human mAbs. Induction of spleen B cell and plasma cells producing immunoglobulins that bound trimeric gp140-GCN4-L was vigorous, based on ELISpot and flow cytometry analyses. The results demonstrate that highly purified gp140-GCN4-L trimer in adjuvant elicits BCN responses in rabbits accompanied by vigorous B cell induction. PMID:24846288

  20. Human Monoclonal Anti-Protective Antigen Antibody Completely Protects Rabbits and Is Synergistic with Ciprofloxacin in Protecting Mice and Guinea Pigs against Inhalation Anthrax

    PubMed Central

    Peterson, Johnny W.; Comer, Jason E.; Noffsinger, David M.; Wenglikowski, Autumn; Walberg, Kristin G.; Chatuev, Bagram M.; Chopra, Ashok K.; Stanberry, Lawrence R.; Kang, Angray S.; Scholz, Wolfgang W.; Sircar, Jagadish

    2006-01-01

    Prevention of inhalation anthrax requires early and extended antibiotic therapy, and therefore, alternative treatment strategies are needed. We investigated whether a human monoclonal antibody (AVP-21D9) to protective antigen (PA) would protect mice, guinea pigs, and rabbits against anthrax. Control animals challenged with Bacillus anthracis Ames spores by the intranasal route died within 3 to 7 days. AVP-21D9 alone provided minimal protection against anthrax in the murine model, but its efficacy was notably better in guinea pigs. When Swiss-Webster mice, challenged with five 50% lethal doses (LD50s) of anthrax spores, were given a single 16.7-mg/kg of body weight AVP-21D9 antibody dose combined with ciprofloxacin (30 mg/kg/day for 6 days) 24 h after challenge, 100% of the mice were protected for more than 30 days, while ciprofloxacin or AVP-21D9 alone showed minimal protection. Similarly, when AVP-21D9 antibody (10 to 50 mg/kg) was combined with a low, nonprotective dose of ciprofloxacin (3.7 mg/kg/day) and administered to guinea pigs for 6 days, synergistic protection against anthrax was observed. In contrast, a single dose of AVP-21D9 antibody (1, 5, 10, or 20 mg/kg) but not 0.2 mg/kg alone completely protected rabbits against challenge with 100 LD50s of B. anthracis Ames spores, and 100% of the rabbits survived rechallenge. Further, administration of AVP-21D9 (10 mg/kg) to rabbits at 0, 6, and 12 h after challenge with anthrax spores resulted in 100% survival; however, delay of antibody treatment by 24 and 48 h reduced survival to 80% and 60%, respectively. Serological analysis of sera from various surviving animals 30 days postprimary infection showed development of a species-specific PA enzyme-linked immunosorbent assay antibody titer that correlated with protection against reinfection. Taken together, the effectiveness of human anti-PA antibody alone or in combination with low ciprofloxacin levels may provide the basis for an improved strategy for

  1. Plasma High-Mannose and Complex/Hybrid N-Glycans Are Associated with Hypercholesterolemia in Humans and Rabbits

    PubMed Central

    Bai, Liang; Li, Qianwei; Li, Lingmei; Lin, Yan; Zhao, Sihai; Wang, Weirong; Wang, Rong; Li, Yongqin; Yuan, Jiangbei; Wang, Chengjian; Wang, Zhongfu; Fan, Jianglin; Liu, Enqi

    2016-01-01

    N-glycans play important roles in various pathophysiological processes and can be used as clinical diagnosis markers. However, plasma N-glycans change and their pathophysiological significance in the setting of hypercholesterolemia, a major risk factor for atherosclerosis, is unknown. Here, we collected plasma from both hypercholesterolemic patients and cholesterol-fed hypercholesterolemic rabbits, and determined the changes in the whole-plasma N-glycan profile by electrospray ionization mass spectrometry. We found that both the hypercholesterolemic patients and rabbits showed a dramatic change in their plasma glycan profile. Compared with healthy subjects, the hypercholesterolemic patients exhibited higher plasma levels of a cluster of high-mannose and complex/hybrid N-glycans (mainly including undecorated or sialylated glycans), whereas only a few fucosylated or fucosylated and sialylated N-glycans were increased. Additionally, cholesterol-fed hypercholesterolemic rabbits also displayed increased plasma levels of high-mannose in addition to high complex/hybrid N-glycan levels. The whole-plasma glycan profiles revealed that the plasma N-glycan levels were correlated with the plasma cholesterol levels, implying that N-glycans may be a target for treatment of hypercholesterolemia. PMID:26999365

  2. Orthologous myosin isoforms and scaling of shortening velocity with body size in mouse, rat, rabbit and human muscles

    PubMed Central

    Pellegrino, M A; Canepari, M; Rossi, R; D'Antona, G; Reggiani, C; Bottinelli, R

    2003-01-01

    Maximum shortening velocity (V0) was determined in single fibres dissected from hind limb skeletal muscles of rabbit and mouse and classified according to their myosin heavy chain (MHC) isoform composition. The values for rabbit and mouse V0 were compared with the values previously obtained in man and rat under identical experimental conditions. Significant differences in V0 were found between fibres containing corresponding myosin isoforms in different species: as a general rule for each isoform V0 decreased with body mass. Myosin isoform distributions of soleus and tibialis anterior were analysed in mouse, rat, rabbit and man: the proportion of slow myosin generally increased with increasing body size. The diversity between V0 of corresponding myosin isoforms and the different myosin isoform composition of corresponding muscles determine the scaling of shortening velocity of whole muscles with body size, which is essential for optimisation of locomotion. The speed of actin translocation (Vf) in in vitro motility assay was determined with myosins extracted from single muscle fibres of all four species: significant differences were found between myosin isoforms in each species and between corresponding myosin isoforms in different species. The values of V0 and Vf determined for each myosin isoform were significantly correlated, strongly supporting the view that the myosin isoform expressed is the major determinant of maximum shortening velocity in muscle fibres. PMID:12562996

  3. Captopril Pretreatment Produces an Additive Cardioprotection to Isoflurane Preconditioning in Attenuating Myocardial Ischemia Reperfusion Injury in Rabbits and in Humans

    PubMed Central

    Tian, Yi; Li, Haobo; Liu, Peiyu; Xu, Jun-mei; Irwin, Michael G.; Xia, Zhengyuan; Tian, Guogang

    2015-01-01

    Background. Pretreatment with the angiotensin-converting inhibitor captopril or volatile anesthetic isoflurane has, respectively, been shown to attenuate myocardial ischemia reperfusion (MI/R) injury in rodents and in patients. It is unknown whether or not captopril pretreatment and isoflurane preconditioning (Iso) may additively or synergistically attenuate MI/R injury. Methods and Results. Patients selected for heart valve replacement surgery were randomly assigned to five groups: untreated control (Control), captopril pretreatment for 3 days (Cap3d), or single dose captopril (Cap1hr, 1 hour) before surgery with or without Iso (Cap3d+Iso and Cap1hr+Iso). Rabbit MI/R model was induced by occluding coronary artery for 30 min followed by 2-hour reperfusion. Rabbits were randomized to receive sham operation (Sham), MI/R (I/R), captopril (Cap, 24 hours before MI/R), Iso, or the combination of captopril and Iso (Iso+Cap). In patients, Cap3d+Iso but not Cap1hr+Iso additively reduced postischemic myocardial injury and attenuated postischemic myocardial inflammation. In rabbits, Cap or Iso significantly reduced postischemic myocardial infarction. Iso+Cap additively reduced cellular injury that was associated with improved postischemic myocardial functional recovery and reduced myocardial apoptosis and attenuated oxidative stress. Conclusion. A joint use of 3-day captopril treatment and isoflurane preconditioning additively attenuated MI/R by reducing oxidative stress and inflammation. PMID:26273143

  4. Rabbit models for continuous curvilinear capsulorhexis instruction

    PubMed Central

    Ruggiero, Jason; Keller, Christopher; Porco, Travis; Naseri, Ayman; Sretavan, David W.

    2012-01-01

    PURPOSE To develop a rabbit model for continuous curvilinear capsulorhexis (CCC) instruction. SETTING University of California San Francisco, San Francisco, California, USA. DESIGN Experimental study. METHODS Isolated rabbit lenses were immersed in 2% to 8% paraformaldehyde (PFA) fixative from 15 minutes to 6 hours. Rabbit eyes were treated by substituting aqueous with 2% to 4% PFA for 30 minutes to 6 hours, followed by washes with a balanced salt solution. Treated lenses and eyes were held in purpose-designed holders using vacuum. A panel of 6 cataract surgeons with 5 to 15 years of experience performed CCC on treated lenses and eyes and responded to a questionnaire regarding the utility of these models for resident teaching using a 5-item Likert scale. RESULTS The expert panel found that rabbit lenses treated with increasing amounts of fixative simulated CCC on human lens capsules from the third to the seventh decade of life. The panel also found fixative-treated rabbit eyes to simulate some of the experience of CCC within the human anterior chamber but noted a shallower anterior chamber depth, variation in pupil size, and corneal clouding under some treatment conditions. CONCLUSIONS Experienced cataract surgeons who performed CCC on these rabbit models strongly agreed that isolated rabbit lenses treated with fixative provide a realistic simulation of CCC in human patients and that both models were useful tools for capsulorhexis instruction. Results indicate that rabbit lenses treated with 8% PFA for 15 minutes is a model with good fidelity for CCC training. PMID:22727296

  5. Risk of zoonotic transmission of HEV from rabbits.

    PubMed

    Lhomme, Sébastien; Dubois, Martine; Abravanel, Florence; Top, Sokunthea; Bertagnoli, Stéphane; Guerin, Jean-Luc; Izopet, Jacques

    2013-10-01

    Hepatitis E virus strains from rabbits indicate that these mammals may be a reservoir for HEVs that cause infection in humans. Further issues remain to be clarified, including whether the genotype of rabbit HEV differs from human and swine HEV genotype 3 and whether rabbit HEV can infect human and other animals. HEV was found in farmed rabbits in several geographic areas of China, in USA and more recently in France. The prevalence of antibodies against HEV was 36%, 57% and 55% in rabbits from Virginia (USA), Gansu Province and Beijing (China), respectively. HEV RNA was detected in 16.5% of serum samples from farmed rabbits in Virginia, 7.5% in Gansu Province and 7.0% in Beijing. HEV RNA was detected in 7% of bile samples from farmed rabbits and in 23% of liver samples from wild rabbits in France. The full-length genomic sequences analysis indicates that all the rabbit strains belong to the same clade. Nucleotide sequences were 72.2-78.2% identical to HEV genotypes 1-4. Comparison with HEV sequences of human strains circulating in France and reference sequences identified a human strain closely related to rabbit HEV. A 93-nucleotide insertion in the X domain of the ORF1 of the human strain and in all the rabbit HEV strains was found. Moreover, the ability of rabbit HEV to cause cross-species infection in a pig model has recently been demonstrated. Rabbit HEV can replicate efficiently in human cell lines. Collectively, these data support the possibility of zoonotic transmission of HEV from rabbits. PMID:23474012

  6. Seroprevalence of toxoplasma gondii infection in domestic rabbits in Durango State, Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii infection in rabbits is of public health importance because rabbit meat is consumed by humans, and rabbits are preyed upon by cats that then shed environmentally resistant oocysts. Antibodies to T. gondii were determined in 429 domestic rabbits in Durango State, Mexico using the mo...

  7. Bone Healing Properties of Autoclaved Autogenous Bone Grafts Incorporating Recombinant Human Bone Morphogenetic Protein-2 and Comparison of Two Delivery Systems in a Segmental Rabbit Radius Defect

    PubMed Central

    Choi, Eun Joo; Kang, Sang-Hoon; Kwon, Hyun-Jin; Cho, Sung-Won; Kim, Hyung Jun

    2014-01-01

    Purpose: This study aims to validate the effect of autoclaved autogenous bone (AAB), incorporating Escherichia coli-derived recombinant human bone morphogenetic protein-2 (ErhBMP-2), on critical-sized, segmental radius defects in rabbits. Delivery systems using absorbable collagen sponge (ACS) and fibrin glue (FG) were also evaluated. Methods: Radius defects were made in 12 New Zealand white rabbits. After autoclaving, the resected bone was reinserted and fixed. The animals were classified into three groups: only AAB reinserted (group 1, control), and AAB and ErhBMP-2 inserted using an ACS (group 2) or FG (group 3) as a carrier. Animals were sacrificed six or 12 weeks after surgery. Specimens were evaluated using radiology and histology. Results: Micro-computed tomography images showed the best bony union in group 2 at six and 12 weeks after operation. Quantitative analysis showed all indices except trabecular thickness were the highest in group 2 and the lowest in group 1 at twelve weeks. Histologic results showed the greatest bony union between AAB and radial bone at twelve weeks, indicating the highest degree of engraftment. Conclusion: ErhBMP-2 increases bony healing when applied on AAB graft sites. In addition, the ACS was reconfirmed as a useful delivery system for ErhBMP-2. PMID:27489818

  8. [Calcium dependence of the contractile response of the aorta in the rat, rabbit and guinea pig and in the human uterine artery].

    PubMed

    García de Boto, M J; Molina, R; Andrés-Trelles, F; Hidalgo, A

    1991-03-01

    The influence of extracellular Ca2+ on the contraction produced by noradrenaline (NA) (3 x 10(-6) M), KCl (60 mM) and BaCl2 (30 mM) on human uterine arteries (AUH) and aortic strips from rats, rabbits and guinea-pigs have been studied. The vessels were cut spirally and incubated in Krebs solution containing 2.5 mM Ca2+ (KN), 0 mM Ca2+ (K-0Ca) or 0 mM Ca2+ + 3 mM EDTA (K-EDTA). Both phases (fast and slow) of the response of aortic strips to NA and of the AUH to NA, KCl and BaCl2 were significantly smaller in solutions without Ca2+. Only in rabbit aortic strips the slow phase was significantly more reduced than the fast phase. Overall, the contractions of the rat aortic strips were most resistant to the absence of extracellular Ca2+. These results confirm the variability of the responses of blood vessels from different vascular beds and species to the removal of extracellular Ca2+. PMID:1908112

  9. Ranibizumab interacts with the VEGF-A/VEGFR-2 signaling pathway in human RPE cells at different levels.

    PubMed

    Ranjbar, Mahdy; Brinkmann, Max Philipp; Tura, Aysegül; Rudolf, Martin; Miura, Yoko; Grisanti, Salvatore

    2016-07-01

    Vascular endothelial growth factor (VEGF) secreted by the retinal pigment epithelium (RPE) plays an important role in ocular homeostasis, but also in diseases, most notably age-related macular degeneration (AMD). To date, anti-VEGF drugs like ranibizumab have been shown to be most effective in treating these pathologic conditions. However, clinical trials suggest that the RPE could degenerate and perish through anti-VEGF treatment. Herein, we evaluated possible pathways and outcomes of the interaction between ranibizumab and human RPE cells (ARPE-19). Results indicate that ranibizumab affects the VEGF-A metabolism in RPE cells from an extra- as well as intracellular site. The drug is taken up into the cells, with the VEGF receptor 2 (VEGFR-2) being involved, and decreases VEGF-A protein levels within the cells as well as extracellularly. Oxidative stress plays a key role in various inflammatory disorders of the eye. Our results suggest that oxidative stress inhibits RPE cell proliferation. This anti-proliferative effect on RPE cells is significantly enhanced through ranibizumab, which does not inhibit RPE cell proliferation substantially in absence of relevant oxidative stress. Therefore, we emphasize that anti-VEGF treatment should be selected carefully in AMD patients with preexistent extensive RPE atrophy. PMID:27163716

  10. Rabbit model for human EBV-associated hemophagocytic syndrome (HPS): sequential autopsy analysis and characterization of IL-2-dependent cell lines established from herpesvirus papio-induced fatal rabbit lymphoproliferative diseases with HPS.

    PubMed

    Hayashi, Kazuhiko; Jin, Zaishun; Onoda, Sachiyo; Joko, Hiromasa; Teramoto, Norihiro; Ohara, Nobuya; Oda, Wakako; Tanaka, Takehiro; Liu, Yi-Xuan; Koirala, Tirtha Raj; Oka, Takashi; Kondo, Eisaku; Yoshino, Tadashi; Takahashi, Kiyoshi; Akagi, Tadaatsu

    2003-05-01

    Epstein-Barr virus-associated hemophagocytic syndrome (EBV-AHS) is often associated with fatal infectious mononucleosis or T-cell lymphoproliferative diseases (LPD). To elucidate the true nature of fatal LPD observed in Herpesvirus papio (HVP)-induced rabbit hemophagocytosis, reactive or neoplastic, we analyzed sequential development of HVP-induced rabbit LPD and their cell lines. All of the seven Japanese White rabbits inoculated intravenously with HVP died of fatal LPD 18 to 27 days after inoculation. LPD was also accompanied by hemophagocytic syndrome (HPS) in five of these seven rabbits. Sequential autopsy revealed splenomegaly and swollen lymph nodes, often accompanied by bleeding, which developed in the last week. Atypical lymphoid cells infiltrated many organs with a "starry sky" pattern, frequently involving the spleen, lymph nodes, and liver. HVP-small RNA-1 expression in these lymphoid cells was clearly demonstrated by a newly developed in situ hybridization (ISH) system. HVP-ISH of immunomagnetically purified lymphoid cells from spleen or lymph nodes revealed HVP-EBER1+ cells in each CD4+, CD8+, or CD79a+ fraction. Hemophagocytic histiocytosis was observed in the lymph nodes, spleen, bone marrow, and thymus. HVP-DNA was detected in the tissues and peripheral blood from the infected rabbits by PCR or Southern blot analysis. Clonality analysis of HVP-induced LPD by Southern blotting with TCR gene probe revealed polyclonal bands, suggesting polyclonal proliferation. Six IL-2-dependent rabbit T-cell lines were established from transplanted scid mouse tumors from LPD. These showed latency type I/II HVP infection and had normal karyotypes except for one line, and three of them showed tumorigenicity in nude mice. These data suggest that HVP-induced fatal LPD in rabbits is reactive polyclonally in nature. PMID:12707056

  11. Viral infections of rabbits.

    PubMed

    Kerr, Peter J; Donnelly, Thomas M

    2013-05-01

    Viral diseases of rabbits have been used historically to study oncogenesis (e.g. rabbit fibroma virus, cottontail rabbit papillomavirus) and biologically to control feral rabbit populations (e.g. myxoma virus). However, clinicians seeing pet rabbits in North America infrequently encounter viral diseases although myxomatosis may be seen occasionally. The situation is different in Europe and Australia, where myxomatosis and rabbit hemorrhagic disease are endemic. Advances in epidemiology and virology have led to detection of other lapine viruses that are now recognized as agents of emerging infectious diseases. Rabbit caliciviruses, related to rabbit hemorrhagic disease, are generally avirulent, but lethal variants are being identified in Europe and North America. Enteric viruses including lapine rotavirus, rabbit enteric coronavirus and rabbit astrovirus are being acknowledged as contributors to the multifactorial enteritis complex of juvenile rabbits. Three avirulent leporid herpesviruses are found in domestic rabbits. A fourth highly pathogenic virus designated leporid herpesvirus 4 has been described in Canada and Alaska. This review considers viruses affecting rabbits by their clinical significance. Viruses of major and minor clinical significance are described, and viruses of laboratory significance are mentioned. PMID:23642871

  12. Novel Interaction Mechanism of a Domain Antibody-based Inhibitor of Human Vascular Endothelial Growth Factor with Greater Potency than Ranibizumab and Bevacizumab and Improved Capacity over Aflibercept*

    PubMed Central

    Walker, Adam; Chung, Chun-Wa; Neu, Margarete; Burman, Manish; Batuwangala, Thil; Jones, Gavin; Tang, Chi-Man; Steward, Michael; Mullin, Michael; Tournier, Nadia; Lewis, Alan; Korczynska, Justyna; Chung, Vicky; Catchpole, Ian

    2016-01-01

    A potent VEGF inhibitor with novel antibody architecture and antigen binding mode has been developed. The molecule, hereafter referred to as VEGF dual dAb (domain antibody), was evaluated in vitro for binding to VEGF and for potency in VEGF-driven models and compared with other anti-VEGF biologics that have been used in ocular anti-angiogenic therapeutic regimes. VEGF dual dAb is more potent than bevacizumab and ranibizumab for VEGF binding, inhibition of VEGF receptor binding assays (RBAs), and VEGF-driven in vitro models of angiogenesis and displays comparable inhibition to aflibercept (Eylea). VEGF dual dAb is dimeric, and each monomer contains two distinct anti-VEGF domain antibodies attached via linkers to a human IgG1 Fc domain. Mechanistically, the enhanced in vitro potency of VEGF dual dAb, in comparison to other anti-VEGF biologics, can be explained by increased binding stoichiometry. A consistent model of the target engagement has been built based on the x-ray complexes of each of the two isolated domain antibodies with the VEGF antigen. PMID:26728464

  13. Simvastatin Induces Regression of Cardiac Hypertrophy and Fibrosis and Improves Cardiac Function in a Transgenic Rabbit Model of Human Hypertrophic Cardiomyopathy

    PubMed Central

    Patel, Rajnikant; Nagueh, Sherif F.; Tsybouleva, Natalie; Abdellatif, Maha; Lutucuta, Silvia; Kopelen, Helen A.; Quinones, Miguel A.; Zoghbi, William A.; Entman, Mark L.; Roberts, Robert; Marian, A.J.

    2009-01-01

    Background Hypertrophic cardiomyopathy is a genetic disease characterized by cardiac hypertrophy, myocyte disarray, interstitial fibrosis, and left ventricular (LV) dysfunction. We have proposed that hypertrophy and fibrosis, the major determinants of mortality and morbidity, are potentially reversible. We tested this hypothesis in β-myosin heavy chain–Q403 transgenic rabbits. Methods and Results We randomized 24 β-myosin heavy chain–Q403 rabbits to treatment with either a placebo or simvastatin (5 mg · kg−1 · d−1) for 12 weeks and included 12 nontransgenic controls. We performed 2D and Doppler echocardiography and tissue Doppler imaging before and after treatment. Demographic data were similar among the groups. Baseline mean LV mass and interventricular septal thickness in nontransgenic, placebo, and simvastatin groups were 3.9±0.7, 6.2±2.0, and 7.5±2.1 g (P<0.001) and 2.2±0.2, 3.1±0.5, and 3.3±0.5 mm (P=0.002), respectively. Simvastatin reduced LV mass by 37%, interventricular septal thickness by 21%, and posterior wall thickness by 13%. Doppler indices of LV filling pressure were improved. Collagen volume fraction was reduced by 44% (P<0.001). Disarray was unchanged. Levels of activated extracellular signal-regulated kinase (ERK) 1/2 were increased in the placebo group and were less than normal in the simvastatin group. Levels of activated and total p38, Jun N-terminal kinase, p70S6 kinase, Ras, Rac, and RhoA and the membrane association of Ras, RhoA, and Rac1 were unchanged. Conclusions Simvastatin induced the regression of hypertrophy and fibrosis, improved cardiac function, and reduced ERK1/2 activity in the β-myosin heavy chain–Q403 rabbits. These findings highlight the need for clinical trials to determine the effects of simvastatin on cardiac hypertrophy, fibrosis, and dysfunction in humans with hypertrophic cardiomyopathy and heart failure. PMID:11457751

  14. Human Immunodeficiency Virus Type 1 Subtype B Ancestral Envelope Protein Is Functional and Elicits Neutralizing Antibodies in Rabbits Similar to Those Elicited by a Circulating Subtype B Envelope

    PubMed Central

    Doria-Rose, N. A.; Learn, G. H.; Rodrigo, A. G.; Nickle, D. C.; Li, F.; Mahalanabis, M.; Hensel, M. T.; McLaughlin, S.; Edmonson, P. F.; Montefiori, D.; Barnett, S. W.; Haigwood, N. L.; Mullins, J. I.

    2005-01-01

    Human immunodeficiency virus type 1 (HIV-1) is a difficult target for vaccine development, in part because of its ever-expanding genetic diversity and attendant capacity to escape immunologic recognition. Vaccine efficacy might be improved by maximizing immunogen antigenic similarity to viruses likely to be encountered by vaccinees. To this end, we designed a prototype HIV-1 envelope vaccine using a deduced ancestral state for the env gene. The ancestral state reconstruction method was shown to be >95% accurate by computer simulation and 99.8% accurate when estimating the known inoculum used in an experimental infection study in rhesus macaques. Furthermore, the deduced ancestor gene differed from the set of sequences used to derive the ancestor by an average of 12.3%, while these latter sequences were an average of 17.3% different from each other. A full-length ancestral subtype B HIV-1 env gene was constructed and shown to produce a glycoprotein of 160 kDa that bound and fused with cells expressing the HIV-1 coreceptor CCR5. This Env was also functional in a virus pseudotype assay. When either gp160- or gp140-expressing plasmids and recombinant gp120 were used to immunize rabbits in a DNA prime-protein boost regimen, the artificial gene induced immunoglobulin G antibodies capable of weakly neutralizing heterologous primary HIV-1 strains. The results were similar for rabbits immunized in parallel with a natural isolate, HIV-1 SF162. Further design efforts to better present conserved neutralization determinants are warranted. PMID:16103173

  15. Human RPE Stem Cells Grown into Polarized RPE Monolayers on a Polyester Matrix Are Maintained after Grafting into Rabbit Subretinal Space

    PubMed Central

    Stanzel, Boris V.; Liu, Zengping; Somboonthanakij, Sudawadee; Wongsawad, Warapat; Brinken, Ralf; Eter, Nicole; Corneo, Barbara; Holz, Frank G.; Temple, Sally; Stern, Jeffrey H.; Blenkinsop, Timothy A.

    2014-01-01

    Summary Transplantation of the retinal pigment epithelium (RPE) is being developed as a cell-replacement therapy for age-related macular degeneration. Human embryonic stem cell (hESC) and induced pluripotent stem cell (iPSC)-derived RPE are currently translating toward clinic. We introduce the adult human RPE stem cell (hRPESC) as an alternative RPE source. Polarized monolayers of adult hRPESC-derived RPE grown on polyester (PET) membranes had near-native characteristics. Trephined pieces of RPE monolayers on PET were transplanted subretinally in the rabbit, a large-eyed animal model. After 4 days, retinal edema was observed above the implant, detected by spectral domain optical coherence tomography (SD-OCT) and fundoscopy. At 1 week, retinal atrophy overlying the fetal or adult transplant was observed, remaining stable thereafter. Histology obtained 4 weeks after implantation confirmed a continuous polarized human RPE monolayer on PET. Taken together, the xeno-RPE survived with retained characteristics in the subretinal space. These experiments support that adult hRPESC-derived RPE are a potential source for transplantation therapies. PMID:24511471

  16. Immunogenicity and some safety features of a VEGF-based cancer therapeutic vaccine in rats, rabbits and non-human primates.

    PubMed

    Morera, Yanelys; Bequet-Romero, Mónica; Ayala, Marta; Velazco, Jorge Castro; Pérez, Pedro Puente; Alba, Jesús Suárez; Ancizar, Julio; Rodríguez, Meilyn; Cosme, Karelia; Gavilondo, Jorge V

    2010-04-26

    We have developed a cancer vaccine candidate (hereafter denominated CIGB-247), based on recombinant modified human vascular endothelial growth factor (VEGF) as antigen, and the adjuvant VSSP (very small sized proteoliposomes of Neisseria meningitidis outer membrane). In mice, previous work of our group had shown that vaccination with CIGB-247 extended tumor-take time, slowed tumor growth, and increased animal survival. Immunization elicited anti-human and murine VEGF-neutralizing antibodies, and spleen cells of vaccinated mice are cytotoxic in vitro to tumor cells that produce VEGF. We have now tested the immunogenicity of CIGB-247 in Wistar rats, New Zealand White rabbits and the non-human primate Chlorocebus aethiops sabaeus. Using weekly, biweekly and biweekly plus montanide immunization schemes, all three species develop antigen-specific IgG antibodies that can block the interaction of VEGF and VEGF receptor 2 in an ELISA assay. Antibody titers decline after vaccination stops, but can be boosted with new immunizations. In monkeys, DTH and direct cell cytotoxicity experiments suggest that specific T-cell responses are elicited by vaccination. Immunization with CIGB-247 had no effect on normal behavior, hematology, blood biochemistry and histology of critical organs, in the tested animals. Skin deep wound healing was not affected in vaccinated rats and monkeys. PMID:20197134

  17. Cloning, Characteristics, and Functional Analysis of Rabbit NADPH Oxidase 5

    PubMed Central

    Chen, Feng; Yin, Caiyong; Dimitropoulou, Christiana; Fulton, David J. R.

    2016-01-01

    Background: Nox5 was the last member of the Nox enzyme family to be identified. Functionally distinct from the other Nox isoforms, our understanding of its physiological significance has been hampered by the absence of Nox5 in mouse and rat genomes. Nox5 is present in the genomes of other species such as the rabbit that have broad utility as models of cardiovascular disease. However, the mRNA sequence, characteristics, and functional analysis of rabbit Nox5 has not been fully defined and were the goals of the current study. Methods: Rabbit Nox5 was amplified from rabbit tissue, cloned, and sequenced. COS-7 cells were employed for expression and functional analysis via Western blotting and measurements of superoxide. We designed and synthesized miRNAs selectively targeting rabbit Nox5. The nucleotide and amino acid sequences of rabbit Nox5 were aligned with those of putative rabbit isoforms (X1, X2, X3, and X4). A phylogenetic tree was generated based on the mRNA sequence for Nox5 from rabbit and other species. Results: Sequence alignment revealed that the identified rabbit Nox5 was highly conserved with the predicted sequence of rabbit Nox5. Cell based experiments reveal that rabbit Nox5 was robustly expressed and produced superoxide at rest and in a calcium and PMA-dependent manner that was susceptible to superoxide dismutase and the flavoprotein inhibitor, DPI. miRNA-1 was shown to be most effective in down-regulating the expression of rabbit Nox5. Phylogenetic analysis revealed a close relationship between rabbit and armadillo Nox5. Rabbit Nox5 was relatively closely related to human Nox5, but lies in a distinct cluster. Conclusion: Our study establishes the suitability of the rabbit as a model organism to further our understanding of the role of Nox5 in cardiovascular and other diseases and provides new information on the genetic relationship of Nox5 genes in different species. PMID:27486403

  18. AGIA Tag System Based on a High Affinity Rabbit Monoclonal Antibody against Human Dopamine Receptor D1 for Protein Analysis

    PubMed Central

    Yano, Tomoya; Takeda, Hiroyuki; Uematsu, Atsushi; Yamanaka, Satoshi; Nomura, Shunsuke; Nemoto, Keiichirou; Iwasaki, Takahiro; Takahashi, Hirotaka; Sawasaki, Tatsuya

    2016-01-01

    Polypeptide tag technology is widely used for protein detection and affinity purification. It consists of two fundamental elements: a peptide sequence and a binder which specifically binds to the peptide tag. In many tag systems, antibodies have been used as binder due to their high affinity and specificity. Recently, we obtained clone Ra48, a high-affinity rabbit monoclonal antibody (mAb) against dopamine receptor D1 (DRD1). Here, we report a novel tag system composed of Ra48 antibody and its epitope sequence. Using a deletion assay, we identified EEAAGIARP in the C-terminal region of DRD1 as the minimal epitope of Ra48 mAb, and we named this sequence the “AGIA” tag, based on its central sequence. The tag sequence does not include the four amino acids, Ser, Thr, Tyr, or Lys, which are susceptible to post-translational modification. We demonstrated performance of this new tag system in biochemical and cell biology applications. SPR analysis demonstrated that the affinity of the Ra48 mAb to the AGIA tag was 4.90 × 10−9 M. AGIA tag showed remarkably high sensitivity and specificity in immunoblotting. A number of AGIA-fused proteins overexpressed in animal and plant cells were detected by anti-AGIA antibody in immunoblotting and immunostaining with low background, and were immunoprecipitated efficiently. Furthermore, a single amino acid substitution of the second Glu to Asp (AGIA/E2D) enabled competitive dissociation of AGIA/E2D-tagged protein by adding wild-type AGIA peptide. It enabled one-step purification of AGIA/E2D-tagged recombinant proteins by peptide competition under physiological conditions. The sensitivity and specificity of the AGIA system makes it suitable for use in multiple methods for protein analysis. PMID:27271343

  19. AGIA Tag System Based on a High Affinity Rabbit Monoclonal Antibody against Human Dopamine Receptor D1 for Protein Analysis.

    PubMed

    Yano, Tomoya; Takeda, Hiroyuki; Uematsu, Atsushi; Yamanaka, Satoshi; Nomura, Shunsuke; Nemoto, Keiichirou; Iwasaki, Takahiro; Takahashi, Hirotaka; Sawasaki, Tatsuya

    2016-01-01

    Polypeptide tag technology is widely used for protein detection and affinity purification. It consists of two fundamental elements: a peptide sequence and a binder which specifically binds to the peptide tag. In many tag systems, antibodies have been used as binder due to their high affinity and specificity. Recently, we obtained clone Ra48, a high-affinity rabbit monoclonal antibody (mAb) against dopamine receptor D1 (DRD1). Here, we report a novel tag system composed of Ra48 antibody and its epitope sequence. Using a deletion assay, we identified EEAAGIARP in the C-terminal region of DRD1 as the minimal epitope of Ra48 mAb, and we named this sequence the "AGIA" tag, based on its central sequence. The tag sequence does not include the four amino acids, Ser, Thr, Tyr, or Lys, which are susceptible to post-translational modification. We demonstrated performance of this new tag system in biochemical and cell biology applications. SPR analysis demonstrated that the affinity of the Ra48 mAb to the AGIA tag was 4.90 × 10-9 M. AGIA tag showed remarkably high sensitivity and specificity in immunoblotting. A number of AGIA-fused proteins overexpressed in animal and plant cells were detected by anti-AGIA antibody in immunoblotting and immunostaining with low background, and were immunoprecipitated efficiently. Furthermore, a single amino acid substitution of the second Glu to Asp (AGIA/E2D) enabled competitive dissociation of AGIA/E2D-tagged protein by adding wild-type AGIA peptide. It enabled one-step purification of AGIA/E2D-tagged recombinant proteins by peptide competition under physiological conditions. The sensitivity and specificity of the AGIA system makes it suitable for use in multiple methods for protein analysis. PMID:27271343

  20. Development of a Zealand white rabbit deposition model to study inhalation anthrax.

    PubMed

    Asgharian, Bahman; Price, Owen; Kabilan, Senthil; Jacob, Richard E; Einstein, Daniel R; Kuprat, Andrew P; Corley, Richard A

    2016-02-01

    Despite using rabbits in several inhalation exposure experiments to study diseases such as anthrax, there is a lack of understanding regarding deposition characteristics and fate of inhaled particles (bio-aerosols and viruses) in the respiratory tracts of rabbits. Such information allows dosimetric extrapolation to humans to inform human outcomes. The lung geometry of the New Zealand white rabbit (referred to simply as rabbits throughout the article) was constructed using recently acquired scanned images of the conducting airways of rabbits and available information on its acinar region. In addition, functional relationships were developed for the lung and breathing parameters of rabbits as a function of body weight. The lung geometry and breathing parameters were used to extend the existing deposition model for humans and several other species to rabbits. Evaluation of the deposition model for rabbits was made by comparing predictions with available measurements in the literature. Deposition predictions in the lungs of rabbits indicated smaller deposition fractions compared to those found in humans across various particle diameter ranges. The application of the deposition model for rabbits was demonstrated by extrapolating deposition predictions in rabbits to find equivalent human exposure concentrations assuming the same dose-response relationship between the two species. Human equivalent exposure concentration levels were found to be much smaller than those for rabbits. PMID:26895308

  1. Three-dimensional bioprinting of multilayered constructs containing human mesenchymal stromal cells for osteochondral tissue regeneration in the rabbit knee joint.

    PubMed

    Shim, Jin-Hyung; Jang, Ki-Mo; Hahn, Sei Kwang; Park, Ju Young; Jung, Hyuntae; Oh, Kyunghoon; Park, Kyeng Min; Yeom, Junseok; Park, Sun Hwa; Kim, Sung Won; Wang, Joon Ho; Kim, Kimoon; Cho, Dong-Woo

    2016-03-01

    The use of cell-rich hydrogels for three-dimensional (3D) cell culture has shown great potential for a variety of biomedical applications. However, the fabrication of appropriate constructs has been challenging. In this study, we describe a 3D printing process for the preparation of a multilayered 3D construct containing human mesenchymal stromal cells with a hydrogel comprised of atelocollagen and supramolecular hyaluronic acid (HA). This construct showed outstanding regenerative ability for the reconstruction of an osteochondral tissue in the knee joints of rabbits. We found that the use of a mechanically stable, host-guest chemistry-based hydrogel was essential and allowed two different types of extracellular matrix (ECM) hydrogels to be easily printed and stacked into one multilayered construct without requiring the use of potentially harmful chemical reagents or physical stimuli for post-crosslinking. To the best of our knowledge, this is the first study to validate the potential of a 3D printed multilayered construct consisting of two different ECM materials (atelocollagen and HA) for heterogeneous tissue regeneration using an in vivo animal model. We believe that this 3D printing-based platform technology can be effectively exploited for regeneration of various heterogeneous tissues as well as osteochondral tissue. PMID:26844597

  2. Cysticercosis in laboratory rabbits.

    PubMed

    Owiny, J R

    2001-03-01

    There are no data on the current incidence of Taenia pisiformis in laboratory rabbits. Two cases of cysticercosis most likely due to T. pisiformis in laboratory rabbits (intermediate host) are presented. Both rabbits had no contact with dogs (final host); their caretakers did not work with dogs, and these caretakers changed into facility scrubs and wore gloves when working with the rabbits. Rabbit 1 may have been infected after being fed hay at our facility. In light of the life cycle of the parasite and the history of rabbit 2, it potentially could have been infected prior to arrival at our facility. There have been only three cases of tapeworm cysts in rabbits in our facility (average daily census, 250) during the last 10 years (incidence, < 1%). This report indicates that although cysticercosis is rare in laboratory rabbits, one should always be aware of such incidental findings. Although it may not produce overt illness in the rabbit, hepatic migration could adversely affect the outcome of some experimental procedures PMID:11300689

  3. A rabbit ear model for cold stress testing.

    PubMed

    Smith, T L; Gordon, S; Holden, M B; Smith, B P; Russell, G B; Koman, L A

    1994-01-01

    A rabbit ear model resembling the human digit was studied to determine the vascular response of the rabbit ear to a cold stress. Following moderate cooling (10 minutes at 5 degrees - 8 degrees C), auricular blood flow and cutaneous perfusion were reduced. This decrease was reversed by 30 minutes of warming. The response in the rabbit ear to cold stress is similar to that of normal human digits. The similarities between the control of the circulation in human digits and rabbit ears may result from the similarities in digital and auricular vascular receptors and receptor subtypes. Verification of the rabbit model provides an experimental method for obtaining important data regarding digital pathophysiology and the treatment of cold intolerance. Further study with this model will provide clinically relevant information regarding the pathophysiology of digital thermoregulatory abnormalities. PMID:7830538

  4. Genomic Analysis of Companion Rabbit Staphylococcus aureus.

    PubMed

    Holmes, Mark A; Harrison, Ewan M; Fisher, Elizabeth A; Graham, Elizabeth M; Parkhill, Julian; Foster, Geoffrey; Paterson, Gavin K

    2016-01-01

    In addition to being an important human pathogen, Staphylococcus aureus is able to cause a variety of infections in numerous other host species. While the S. aureus strains causing infection in several of these hosts have been well characterised, this is not the case for companion rabbits (Oryctolagus cuniculus), where little data are available on S. aureus strains from this host. To address this deficiency we have performed antimicrobial susceptibility testing and genome sequencing on a collection of S. aureus isolates from companion rabbits. The findings show a diverse S. aureus population is able to cause infection in this host, and while antimicrobial resistance was uncommon, the isolates possess a range of known and putative virulence factors consistent with a diverse clinical presentation in companion rabbits including severe abscesses. We additionally show that companion rabbit isolates carry polymorphisms within dltB as described as underlying host-adaption of S. aureus to farmed rabbits. The availability of S. aureus genome sequences from companion rabbits provides an important aid to understanding the pathogenesis of disease in this host and in the clinical management and surveillance of these infections. PMID:26963381

  5. Genomic Analysis of Companion Rabbit Staphylococcus aureus

    PubMed Central

    Holmes, Mark A.; Harrison, Ewan M.; Fisher, Elizabeth A.; Graham, Elizabeth M.; Parkhill, Julian; Foster, Geoffrey; Paterson, Gavin K.

    2016-01-01

    In addition to being an important human pathogen, Staphylococcus aureus is able to cause a variety of infections in numerous other host species. While the S. aureus strains causing infection in several of these hosts have been well characterised, this is not the case for companion rabbits (Oryctolagus cuniculus), where little data are available on S. aureus strains from this host. To address this deficiency we have performed antimicrobial susceptibility testing and genome sequencing on a collection of S. aureus isolates from companion rabbits. The findings show a diverse S. aureus population is able to cause infection in this host, and while antimicrobial resistance was uncommon, the isolates possess a range of known and putative virulence factors consistent with a diverse clinical presentation in companion rabbits including severe abscesses. We additionally show that companion rabbit isolates carry polymorphisms within dltB as described as underlying host-adaption of S. aureus to farmed rabbits. The availability of S. aureus genome sequences from companion rabbits provides an important aid to understanding the pathogenesis of disease in this host and in the clinical management and surveillance of these infections. PMID:26963381

  6. Complement activation induced by rabbit rheumatoid factor.

    PubMed Central

    Meyer, R R; Brown, J C

    1980-01-01

    Rabbit rheumatoid factor produced in animals by hyperimmunized with group C streptococcal vaccine activated guinea pig complement. Anti-streptococcal serum was fractionated by Sephacryl S-200 chromatography into excluded (19S) and included (7S) material and examined for hemolytic activity in a sensitive homologous hemolytic assay system. In the presence of complement, both 19S and 7S antistreptococcal serum fractions induced lysis of bovine (ox) erythrocytes coated with mildly reduced and carboxymethylated rabbit anti-erythrocyte immunoglobulin G. That rabbit rheumatoid factor was responsible for the observed hemolytic activity was substantiated by hemolytic inhibition assays. Significant inhibition of hemolysis was effected when antistreptococcal serum fractions were incubated in the presence of human immunoglobulin G, rabbit immunoglobulin G, and Fc, whereas, no inhibition was detected when the same fractions were tested in the presence of rabbit Fab or F(ab')2 fragments. Deaggregation of inhibitor preparations revealed a preferential reactivity of rheumatoid factor for rabbit immunoglobulin G. In addition to the rheumatoid factor-dependent hemolytic activity observed in humoral preparations, immunoglobulin G-specific antibody-forming cells in spleen and peripheral blood lymphocyte isolates were enumerated by plaque-forming cell assay. PMID:7399707

  7. Observation of Human Retinal Remodeling in Octogenarians with a Resveratrol Based Nutritional Supplement

    PubMed Central

    Richer, Stuart; Stiles, William; Ulanski, Lawrence; Carroll, Donn; Podella, Carla

    2013-01-01

    Purpose: Rare spontaneous remissions from age-related macular degeneration (AMD) suggest the human retina has large regenerative capacity, even in advanced age. We present examples of robust improvement of retinal structure and function using an OTC oral resveratrol (RV) based nutritional supplement called Longevinex® or L/RV (circa 2004, Resveratrol Partners, LLC, Las Vegas, NV, USA). RV, a polyphenolic phytoalexin caloric-restriction mimic, induces hormesis at low doses with widespread beneficial effects on systemic health. RV alone inhibits neovascularization in the murine retina. Thus far, published evidence includes L/RV mitigation of experimentally induced murine cardiovascular reperfusion injury, amelioration of human atherosclerosis serum biomarkers in a human Japanese randomized placebo controlled trial, modulation of micro RNA 20b and 539 that control hypoxia-inducing-factor (HIF-1) and vascular endothelial growth factor (VEGF) genes in the murine heart (RV inhibited micro RNA20b 189-fold, L/RV 1366-fold). Little is known about the effects of L/RV on human ocular pathology. Methods: Absent FDA IRB approval, but with permission from our Chief of Staff and medical center IRB, L/RV is reserved for AMD patients, on a case-by-case compassionate care basis. Patients include those who progress on AREDS II type supplements, refuse intra-vitreal anti-VEGF injections or fail to respond to Lucentis®, Avastin® or Eylea®. Patients are clinically followed traditionally as well as with multi-spectral retinal imaging, visual acuity, contrast sensitivity, cone glare recovery and macular visual fields. Three cases are presented. Results: Observed dramatic short-term anti-VEGF type effect including anatomic restoration of retinal structure with a suggestion of improvement in choroidal blood flow by near IR multispectral imaging. The visual function improvement mirrors the effect seen anatomically. The effect is bilateral with the added benefit of better RPE function

  8. Astroviruses in Rabbits

    PubMed Central

    Moschidou, Paschalina; Pinto, Pierfrancesco; Catella, Cristiana; Desario, Constantina; Larocca, Vittorio; Circella, Elena; Bànyai, Krisztian; Lavazza, Antonio; Magistrali, Chiara; Decaro, Nicola; Buonavoglia, Canio

    2011-01-01

    By screening rabbits with enterocolitis or enteritis complex and asymptomatic rabbits, we identified a novel astrovirus. The virus was distantly related (19.3%–23.7% aa identity) in the capsid precursor to other mammalian astroviruses within the Mamastrovirus genus. By using real-time reverse transcription PCR, with specific primers and probes and targeting a conserved stretch in open reading frame 1b, we found rabbit astrovirus in 10 (43%) of 23 samples from animals with enteric disease and in 25 (18%) of 139 samples from asymptomatic animals in Italy during 2005–2008. The mean and median titers in the positive animals were 102× and 103× greater, respectively, in the symptomatic animals than in the asymptomatic animals. These findings support the idea that rabbit astroviruses should be included in the diagnostic algorithm of rabbit enteric disease and animal experiments to increase information obtained about their epidemiology and potential pathogenic role. PMID:22172457

  9. Correlation between serum bactericidal activity against Neisseria meningitidis serogroups A, C, W-135 and Y measured using human versus rabbit serum as the complement source.

    PubMed

    Gill, C J; Ram, S; Welsch, J A; Detora, L; Anemona, A

    2011-12-01

    The surrogate of protection against invasive meningococcal disease is the presence of serum bactericidal activity (SBA) at a titer ≥4 in an assay using human serum as the complement source (hSBA). However, for various practical and logistical reasons, many meningococcal vaccines in use today were licensed based on a modified SBA assay that used baby rabbit serum as the complement source (rSBA). To assess the strength of correlation between the two assay systems for serogroups A, C, W-135 and Y, we analyzed a subset of samples from adolescent subjects enrolled in a Phase II study of Novartis' MenACWY-CRM conjugate vaccine vs. an ACWY polysaccharide vaccine; samples were analyzed in parallel using hSBA and rSBA. We compared geometric mean titers (GMTs), calculated Pearson correlation coefficients between paired hSBA and rSBA results, and calculated sensitivity/specificity and likelihood ratios for an rSBA ≥8 or ≥128 for classifying hSBA ≥4, taking hSBA as the 'gold standard'. Correlations between hSBA and rSBA ranged from 0.46 to 0.78 for serogroup C, but were weaker for serogroups A, W-135 and Y (range -0.15 to 0.57). In post vaccination samples, nearly all subjects had rSBA titers ≥8, though up to 15% remained seronegative by hSBA. In post vaccination settings, rSBA titers at ≥8 or ≥128 was highly sensitive for an hSBA titer ≥4, but non-specific. In conclusion, results generated by rSBA did not accurately classify serostatus according to hSBA for serogroups A, W-135 and Y. PMID:22075087

  10. [Experimental study on application recombinant human bone morphogenetic protein 2(rhBMP-2)/poly-lactide-co-glycolic acid (PLGA)/fibrin sealant(FS) on repair of rabbit radial bone defect].

    PubMed

    Fan, Zhongkai; Cao, Yang; Zhang, Zhe; Zhang, Mingchao; Lu, Wei; Tang, Lei; Yao, Qi; Lu, Gang

    2012-10-01

    This paper is aimed to investigate the repair of rabbit radial bone defect by the recombinant human bone morphogenetic protein 2/poly-lactideco-glycolic acid microsphere with fibrin sealant (rhBMP-2/PLGA/FS). The radial bone defect models were prepared using New Zealand white rabbits, which were randomly divided into 3 groups, experiment group which were injected with eMP-2/PLGA/FS at bone defect location, control group which were injected with FS at bone defect location, and blank control group without treatment. The ability of repairing bone defect was evaluated with X-ray radiograph. Bone mineral density in the defect regions was analysed using the level of ossification. The osteogenetic ability of repairing bone defect, the degradation of the material, the morphologic change and the bone formation were assessed by HE staining and Masson staining. The result showed that rhBMP-2/PLGA/FS had overwhelming superiority in the osteogenetic ability and quality of bone defect over the control group, and it could promote the repair of bone defect and could especially repair the radial bone defect of rabbit well. It may be a promising and efficient synthetic bone graft. PMID:23198432

  11. Epitope specificity of rabbit immunoglobulin G (IgG) elicited by pneumococcal type 23F synthetic oligosaccharide- and native polysaccharide-protein conjugate vaccines: comparison with human anti-polysaccharide 23F IgG.

    PubMed Central

    Alonso de Velasco, E; Verheul, A F; van Steijn, A M; Dekker, H A; Feldman, R G; Fernández, I M; Kamerling, J P; Vliegenthart, J F; Verhoef, J; Snippe, H

    1994-01-01

    Streptococcus pneumoniae type 23F capsular polysaccharide (PS23F) consitss of a repeating glycerol-phosphorylated branched tetrasaccharide. The immunogenicities of the following related antigens were investigated: (i) a synthetic trisaccharide comprising the backbone of one repeating unit, (ii) a synthetic tetrasaccharide comprising the complete repeating unit, and (iii) native PS23F (all three conjugated to keyhole limpet hemocyanin [KLH]) and (iv) formalin-killed S. pneumoniae 23F. All antigens except the trisaccharide-KLH conjugate induced relatively high anti-PS23F antibody levels in rabbits. The epitope specificity of such antibodies was then studied by means of an inhibition immunoassay. The alpha(1-->2)-linked L-rhamnose branch was shown to be immunodominant for immunoglobulin G (IgG) induced by tetrasaccharide-KLH, PS23F-KLH, and killed S. pneumoniae 23F: in most sera L-rhamnose totally inhibited the binding of IgG to PS23F. Thus, there appears to be no major difference in epitope specificity between IgG induced by tetrasaccharide-KLH and that induced by antigens containing the polymeric form of PS23F. Human anti-PS23F IgG (either vaccine induced or naturally acquired) had a different epitope specificity: none of the inhibitors used, including L-rhamnose and tetrasaccharide-KLH, exhibited substantial inhibition. These observations suggest that the epitope recognized by human IgG on PS23F is larger than the epitope recognized by rabbit IgG. Both human and rabbit antisera efficiently opsonized type 23F pneumococci, as measured in a phagocytosis assay using human polymorphonuclear leukocytes. PMID:7509318

  12. Anti-VEGF in a Marathon Runner's Retinopathy Case.

    PubMed

    Soon, Alexander Kahjun; de Oliveira, Paulo Ricardo Chaves; Chow, David Robert

    2016-01-01

    Central retinal vein occlusion (CRVO) is one of the most common retinal vascular disorders. Intense exercise associated CRVO have been described in otherwise healthy young patients. We describe a case of a young male ultramarathoner who presented with a CRVO, presumably associated with dehydration, making part of a marathon runner's retinopathy. Resolution of macular edema and subretinal fluid, with visual acuity improvement, was observed after 3 monthly injections of ranibizumab. Our case suggests that dehydration could be involved in the mechanism of CRVO in healthy young patients and ranibizumab may be an effective treatment option for marathon runner's retinopathy. PMID:27418990

  13. Anti-VEGF in a Marathon Runner's Retinopathy Case

    PubMed Central

    Soon, Alexander Kahjun

    2016-01-01

    Central retinal vein occlusion (CRVO) is one of the most common retinal vascular disorders. Intense exercise associated CRVO have been described in otherwise healthy young patients. We describe a case of a young male ultramarathoner who presented with a CRVO, presumably associated with dehydration, making part of a marathon runner's retinopathy. Resolution of macular edema and subretinal fluid, with visual acuity improvement, was observed after 3 monthly injections of ranibizumab. Our case suggests that dehydration could be involved in the mechanism of CRVO in healthy young patients and ranibizumab may be an effective treatment option for marathon runner's retinopathy. PMID:27418990

  14. Anti-VEGF Anticancer Drugs: Mind the Hypertension.

    PubMed

    Katsi, Vasiliki; Zerdes, Ioannis; Manolakou, Stavroula; Makris, Thomas; Nihoyannopoulos, Petros; Tousoulis, Dimitris; Kallikazaros, Ioannis

    2014-01-01

    The introduction of therapies that inhibit tumor angiogenesis and particularly target to vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor (VEGFR) (VEGF inhibitors/VEGFi) have revolutionized the treatment of various cancer types. Although their clinical benefit can be optimal for cancer-affected patients, the safety of these targeted agents is of special concern especially for longer-term adjuvant or maintenance treatment. Importantly, VEGFi therapy has been significantly associated with hypertension (HTN) as an adverse effect and therefore the control of blood pressure (BP) after the administration of these drugs remains a challenging matter to be faced. The aim of this review is to summarize studies which investigate the association of VEGFi agents with HTN manifestation and the possible risks associated with this complication. Additionally, given that the optimal management of HTN caused by VEGFi remains obscure, this review will focus on prevention strategies including BP monitoring plans and propose potential therapeutic approaches. PMID:26123049

  15. Anti-VEGF therapy for diabetic macular edema.

    PubMed

    Stewart, Michael W

    2014-08-01

    Vascular endothelial growth factor (VEGF) plays a pivotal role in the development of diabetic macular edema (DME), the leading cause of vision loss among working-aged individuals. A decade of clinical trials demonstrated that drugs that bind soluble VEGF restore the integrity of the blood-retinal barrier, resolve macular edema, and improve vision in most patients with DME. Four drugs (pegaptanib, ranibizumab, bevacizumab, and aflibercept) effectively treat DME when administered by intravitreal injections. Only ranibizumab has received U.S. Food and Drug Administration (FDA) approval for DME, but bevacizumab is commonly used off-label, and an FDA application for aflibercept is pending. Effective treatment requires repeated injections, although recent data suggest that the treatment burden diminishes after 1 year. Intravitreal therapy is generally safe, although the incidence of systemic thromboembolic events varies among trials. PMID:24919750

  16. Pathologic Findings in Rabbit Models of Hereditary Hypertriglyceridemia and Hereditary Postprandial Hypertriglyceridemia

    PubMed Central

    Mitsuguchi, Yoko; Ito, Tsunekata; Ohwada, Kazuo

    2008-01-01

    In recent years, the association between hyperlipidemia and the development of arteriosclerosis has been addressed in several studies. Rabbit models of hypertriglyceridemia (TGH) and postprandial hypertriglyceridemia (PHT) have been developed at the authors' institute. TGH rabbits manifest pathology similar to that of humans with TGH, such as xanthoma, in addition to atherosclerosis of arterioles. Furthermore, PHT rabbits show visceral obesity, insulin resistance, and impaired glucose tolerance, with pathologic features similar to those of the metabolic syndrome assumed to be the cause of human ischemic heart disease. This study was designed to investigate the histopathologic features of TGH and PHT rabbits. TGH rabbits showed advanced aortic atherosclerosis, accompanied by intimal thickening of coronary and renal arteries, fatty liver changes, and xanthoma. PHT rabbits demonstrated aortic intimal thickening and hepatic fatty degeneration. The results of this study suggest that TGH and PHT rabbits are useful animal models for studying human hyperlipidemia and metabolic syndrome and the cardiovascular diseases that result from these conditions. PMID:19004373

  17. Oil well rabbit

    SciTech Connect

    Yerian, H.W.

    1983-10-18

    A well rabbit is described which has a high gas seal capacity as well as resistance to wear and structural failure. The rabbit comprises a one-piece elongated generally cylindrical body having external circumferential gas-sealing grooves spaced along its length and a set of helically oriented slots at its lower end. The circumferential grooves, which work collectively in the manner of a labyrinth seal, are undercut in a way to deflect escaping gas streams and promote turbulence to enhance their gas-sealing capability. The undercut profile and relative spacing of the grooves leaves a large surface area between the grooves for distributing radial forces and thereby decreasing the wear rate of the rabbit. The helically oriented slots convert energy of upward escaping gas into rotational energy in the rabbit. (3 claims.

  18. Viral diseases of the rabbit.

    PubMed

    Krogstad, Aric P; Simpson, Janet E; Korte, Scott W

    2005-01-01

    Viral disease in the rabbit is encountered infrequently by the clinical practitioner; however, several viral diseases were reported to occur in this species. Viral diseases that are described in the rabbit primarily may affect the integument, gastrointestinal tract or, central nervous system or maybe multi-systemic in nature. Rabbit viral diseases range from oral papillomatosis, with benign clinical signs, to rabbit hemorrhagic disease and myxomatosis, which may result in significant clinical disease and mortality. The wild rabbit may serve as a reservoir for disease transmission for many of these viral agents. In general, treatment of viral disease in the rabbit is supportive in nature. PMID:15585192

  19. Poikilocytosis in Rabbits: Prevalence, Type, and Association with Disease

    PubMed Central

    Christopher, Mary M.; Hawkins, Michelle G.; Burton, Andrew G.

    2014-01-01

    Rabbits (Oryctolagus cuniculus) are a popular companion animal, food animal, and animal model of human disease. Abnormal red cell shapes (poikilocytes) have been observed in rabbits, but their significance is unknown. The objective of this study was to investigate the prevalence and type of poikilocytosis in pet rabbits and its association with physiologic factors, clinical disease, and laboratory abnormalities. We retrospectively analyzed blood smears from 482 rabbits presented to the University of California-Davis Veterinary Medical Teaching Hospital from 1990 to 2010. Number and type of poikilocytes per 2000 red blood cells (RBCs) were counted and expressed as a percentage. Acanthocytes (>3% of RBCs) were found in 150/482 (31%) rabbits and echinocytes (>3% of RBCs) were found in 127/482 (27%) of rabbits, both healthy and diseased. Thirty-three of 482 (7%) rabbits had >30% acanthocytes and echinocytes combined. Mild to moderate (>0.5% of RBCs) fragmented red cells (schistocytes, microcytes, keratocytes, spherocytes) were found in 25/403 (6%) diseased and 0/79 (0%) healthy rabbits (P = 0.0240). Fragmentation and acanthocytosis were more severe in rabbits with inflammatory disease and malignant neoplasia compared with healthy rabbits (P<0.01). The % fragmented cells correlated with % polychromasia, RDW, and heterophil, monocyte, globulins, and fibrinogen concentrations (P<0.05). Echinocytosis was significantly associated with renal failure, azotemia, and acid-base/electrolyte abnormalities (P<0.05). Serum cholesterol concentration correlated significantly with % acanthocytes (P<0.0001), % echinocytes (P = 0.0069), and % fragmented cells (P = 0.0109), but correlations were weak (Spearman ρ <0.02). These findings provide important insights into underlying pathophysiologic mechanisms that appear to affect the prevalence and type of naturally-occurring poikilocytosis in rabbits. Our findings support the need to carefully document poikilocytes in research

  20. Lack of antibodies to human heart tissue in sera of rhesus monkeys immunized with Streptococcus mutans antigens and comparative study with rabbit antisera.

    PubMed Central

    Bergmeier, L A; Lehner, T

    1983-01-01

    Immunization of rabbits and rhesus monkeys with Streptococcus mutans whole cells, cell walls, and defined streptococcal antigens (SAs) SA I/II, SA I, and SA II resulted in high antibody titers to SA I/II (10(-4) to 10(-6)) when tested by the solid-phase radioimmunoassay. Cross-reactive antibodies to heart homogenates (HH) were not elicited in rhesus monkeys. A few rabbits immunized with cell wall or SA II preparation in Freund complete adjuvant followed by the incomplete adjuvant yielded low antibody titers (up to 10(-2)) to the HH. The specificity of the putative heart cross-reactive antibodies was tested by immunoadsorption with related and unrelated antigens. Whereas antibody to SA I/II showed specific adsorption with SA I/II but not with HH, immunoglobulin G, or the unrelated antigens, antibody to HH seemed to have been adsorbed with all of the related and unrelated antigens. There was no evidence for the development of heart cross-reactive antibodies on immunization of rhesus monkeys or rabbits with SA I/II and aluminium hydroxide or Freund incomplete adjuvant, administered by the subcutaneous or intramuscular route in doses of up to 13 mg of the immunogen. PMID:6852912

  1. A Herpes Simplex Virus Type 1 Human Asymptomatic CD8+ T-Cell Epitopes-Based Vaccine Protects Against Ocular Herpes in a “Humanized” HLA Transgenic Rabbit Model

    PubMed Central

    Srivastava, Ruchi; Khan, Arif A.; Huang, Jiawei; Nesburn, Anthony B.; Wechsler, Steven L.; BenMohamed, Lbachir

    2015-01-01

    Purpose. A clinical vaccine that protects from ocular herpes simplex virus type 1 (HSV-1) infection and disease still is lacking. In the present study, preclinical vaccine trials of nine asymptomatic (ASYMP) peptides, selected from HSV-1 glycoproteins B (gB), and tegument proteins VP11/12 and VP13/14, were performed in the “humanized” HLA–transgenic rabbit (HLA-Tg rabbit) model of ocular herpes. We recently reported that these peptides are highly recognized by CD8+ T cells from “naturally” protected HSV-1–seropositive healthy ASYMP individuals (who have never had clinical herpes disease). Methods. Mixtures of three ASYMP CD8+ T-cell peptides derived from either HSV-1 gB, VP11/12, or VP13/14 were delivered subcutaneously to different groups of HLA-Tg rabbits (n = 10) in incomplete Freund's adjuvant, twice at 15-day intervals. The frequency and function of HSV-1 epitope-specific CD8+ T cells induced by these peptides and their protective efficacy, in terms of survival, virus replication in the eye, and ocular herpetic disease were assessed after an ocular challenge with HSV-1 (strain McKrae). Results. All mixtures elicited strong and polyfunctional IFN-γ– and TNF-α–producing CD107+CD8+ cytotoxic T cells, associated with a significant reduction in death, ocular herpes infection, and disease (P < 0.015). Conclusions. The results of this preclinical trial support the screening strategy used to select the HSV-1 ASYMP CD8+ T-cell epitopes, emphasize their valuable immunogenic and protective efficacy against ocular herpes, and provide a prototype vaccine formulation that may be highly efficacious for preventing ocular herpes in humans. PMID:26098469

  2. Anti-Human VEGF Repebody Effectively Suppresses Choroidal Neovascularization and Vascular Leakage

    PubMed Central

    Hwang, Da-Eun; Ryou, Jeong-Hyun; Oh, Jong Rok; Han, Jung Woo; Park, Tae Kwann; Kim, Hak-Sung

    2016-01-01

    Age-related macular degeneration (AMD) is the leading cause of vision loss and blindness among people over the age of 60. Vascular endothelial growth factor (VEGF) plays a major role in pathological angiogenesis in AMD. Herein, we present the development of an anti- human VEGF repebody, which is a small-sized protein binder consisting of leucine-rich repeat (LRR) modules. The anti-VEGF repebody selected through a phage-display was shown to have a high affinity and specificity for human VEGF. We demonstrate that this repebody effectively inhibits in vitro angiogenic cellular processes, such as proliferation and migration, by blocking the VEGF-mediated signaling pathway. The repebody was also shown to have a strong suppression effect on choroidal neovascularization (CNV) and vascular leakage in vivo. Our results indicate that the anti-VEGF repebody has a therapeutic potential for treating neovascular AMD as well as other VEGF-involved diseases including diabetic retinopathy and metastatic cancers. PMID:27015541

  3. Serological survey of hepatitis E virus infection in farmed and pet rabbits in Italy.

    PubMed

    Di Bartolo, Ilaria; De Sabato, L; Marata, A; Martinelli, N; Magistrali, C F; Monini, M; Ponterio, E; Ostanello, F; Ruggeri, F M

    2016-05-01

    The recent identification in rabbits of hepatitis E viruses (HEV) related to viruses infecting humans raises the question of the role of this species as possible HEV reservoir. A serological survey on rabbit HEV infection was conducted in Italy during 2013-2014, including both farmed and pet rabbits. We found an anti-HEV antibody seroprevalence of 3.40 % in 206 farmed rabbits (collected on 7 farms) and 6.56 % in 122 pets. RNA was extracted from IgG-positive sera and analyzed by HEV-specific real-time RT-PCR. None of the samples were positive, confirming that no viremia was present in the presence of IgG. Only one serum sample from a farmed rabbit was positive for IgM, but no HEV RNA was detected in it. Pet rabbit feces were also tested for HEV RNA, with negative results. This finding suggests that HEV is circulating in rabbits in Italy. PMID:26873813

  4. The Cutaneous Rabbit Revisited

    ERIC Educational Resources Information Center

    Flach, Rudiger; Haggard, Patrick

    2006-01-01

    In the cutaneous rabbit effect (CRE), a tactile event (so-called attractee tap) is mislocalized toward an adjacent attractor tap. The effect depends on the time interval between the taps. The authors delivered sequences of taps to the forearm and asked participants to report the location of one of the taps. The authors replicated the original CRE…

  5. On the metabolic detoxication of thymol in rabbit and man.

    PubMed

    Takada, M; Agata, I; Sakamoto, M; Yagi, N; Hayashi, N

    1979-11-01

    The metabolic detoxication of thymol was investigated in rabbit and man. Thymol glucuronide which the aglycone is intact, was isolated from thymol medicated rabbit urine and identified as a acetyl derivative of methyl glucuronate. The hydroxylated product of thymol, thymohydroquinone, was recognized in a small amount in thymol medicated human urine. It was presumed that thymohydroquinone is excreted as ethereal sulfuric acid conjugate in man. PMID:548583

  6. [The implantation of lyophilized and gamma-sterilized allogenetic incus and of lyophilized and gamma-sterilized xenogenetic malleus (calf) in rabbits and humans (author's transl)].

    PubMed

    Eitschberger, E; Heine, W D; Gammert, C; Richter, W

    1977-06-30

    The histological reactions to the implantation of allogenetic and xenogenetic lyophilized and gamma-sterilized material into the middle ear of rabbits and men is described. In contrary to the behaviour of allogenetic material the xenogenetic shows a clear minor tendency of revitalisation. The reason is the antigen-antibody-reaction which takes place at the capillary network of the donor and leads to a hylinosis with following obliteration of the vascular rete. Therefore the angiogenetic osteogenesis cannot develop. The clinical usuability of such material is discussed. PMID:578413

  7. Identification and expression of an allergen Asp f 13 from Aspergillus fumigatus and epitope mapping using human IgE antibodies and rabbit polyclonal antibodies.

    PubMed Central

    Chow, L P; Liu, S L; Yu, C J; Liao, H K; Tsai, J J; Tang, T K

    2000-01-01

    The Aspergillus genus of fungi is known to be one of the most prevalent aeroallergens. On two-dimensional immunoblotting using patients' sera containing IgE specific for Asp f 13, an allergen with a molecular mass of 33 kDa and a pI of 6.2 was identified. This allergen was also present in A. fumigatus culture filtrates. Furthermore, the sequence of the Asp f 13 cDNA was identical to that for alkaline protease isolated from A. fumigatus and showed 42-49% identity of amino acids with two proteases from P. cyclopium and T. album and with the Pen c 1 allergen from P. citrinum. Asp f 13 coding sequences were expressed in Escherichia coli as a [His](6)-tagged fusion protein which was purified by Ni(2+)-chelate affinity chromatography. Recombinant Asp f 13 was recognized by rabbit polyclonal antibodies against Asp f 13 and by IgE antibodies from subject allergic to A. fumigatus. To identify and characterize the linear epitopes of this allergen, a combination of chemical and enzymatic cleavage and immunoblotting techniques, with subsequent N-terminal sequencing and mass spectrometry, were performed. At least 13 different linear epitopes reacting with the rabbit anti-Asp f 13 antiserum were identified, located throughout the entire molecule. In contrast, IgE from A. fumigatus-sensitive patients bound to three immunodominant epitopes at the C-terminal of the protein. PMID:10677362

  8. The Rabbit as a Model for Studying Lung Disease and Stem Cell Therapy

    PubMed Central

    Kamaruzaman, Nurfatin Asyikhin; Kamaldin, Nurulain ‘Atikah; Latahir, Ahmad Zaeri; Yahaya, Badrul Hisham

    2013-01-01

    No single animal model can reproduce all of the human features of both acute and chronic lung diseases. However, the rabbit is a reliable model and clinically relevant facsimile of human disease. The similarities between rabbits and humans in terms of airway anatomy and responses to inflammatory mediators highlight the value of this species in the investigation of lung disease pathophysiology and in the development of therapeutic agents. The inflammatory responses shown by the rabbit model, especially in the case of asthma, are comparable with those that occur in humans. The allergic rabbit model has been used extensively in drug screening tests, and this model and humans appear to be sensitive to similar drugs. In addition, recent studies have shown that the rabbit serves as a good platform for cell delivery for the purpose of stem-cell-based therapy. PMID:23653896

  9. The use of C1q, conglutinin and low affinity rabbit IgM antibody to human Fc in a ligand coctail radioassay for detecting and characterizing immune complexes in pathological sera.

    PubMed Central

    Harkiss, G D; Brown, D L

    1980-01-01

    A ligand radioassay for the detection of IC which utilizes C1q, bovine conglutinin and low affinity rabbit IgM anti-human Fc in a reagent coctail, is presented. IC are first isolated from serum by precipitation in polyethylene glycol, then analysed for their ability to react with the ligand coctail. Dual-label studies with 125I and 131I-tagged ligands, designed to determine whether the ligands bound independently to IC, indicate that the binding of each ligand to IC is not significantly affected by the presence of the other two ligands. The results of assaying pathological sera for IC by the ligand coctail radioassay correlate well with the results of three other assays. The assay system is also flexible enough to allow other low affinity IgM reagents to be used which could potentially cover the whole range of immunoglobulin classes occurring in pathological IC. PMID:7379330

  10. Simple adult rabbit model for Campylobacter jejuni enteritis.

    PubMed Central

    Caldwell, M B; Walker, R I; Stewart, S D; Rogers, J E

    1983-01-01

    We tested the usefulness of the Removable Intestinal Tie Adult Rabbit Diarrhea model to establish Campylobacter jejuni infection in rabbits. The procedure involved ligation of the cecum, placement of a slip knot at the terminal ileum, and injection of the test inoculum into the mid-small bowel. The ends of the slip knot were externalized, and the tie was released 4 h later. Fifty-five rabbits received C. jejuni, and 16 received uninoculated medium as controls. Daily rectal swabs were positive for 2 weeks in infected rabbits. The diarrheal attack rate was 64% in infected rabbits and 0% in controls. Diarrhea was characterized by loose, mucus-containing stools after an incubation period ranging from 24 h to 6 days. When blood was obtained daily for culture from 30 rabbits for 4 days post-challenge, bacteremia was present in 96.3% 24 h after challenge but diminished to 5 of 19 (26.3%) at 96 h. Death occurred in 53% of rabbits and was always preceded by diarrhea. No control animal died. Only 5 of 35 animals experiencing diarrhea recovered. An indirect whole-cell enzyme-linked immunosorbent assay was used to determine serum immunoglobulin G responses. Mean titers rose from 1:198 preoperatively to 1:9,087 on day 28. Necropsy on eight infected and two control animals showed inflammatory lesions with ulceration in 62.5% and goblet cell hyperplasia in 75% of infected rabbits. We conclude that the Removable Intestinal Tie Adult Rabbit Diarrhea procedure is a simple, effective method to establish C. jejuni infection which mimics human disease. Images PMID:6642664