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Platelet-instructed SPP1 + macrophages drive myofibroblast activation in fibrosis in a CXCL4-dependent manner. Cell Rep 2023; 42:112131. [PMID: 36807143 PMCID: PMC9992450 DOI: 10.1016/j.celrep.2023.112131] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 11/11/2022] [Accepted: 01/31/2023] [Indexed: 02/19/2023] Open
Abstract
Fibrosis represents the common end stage of chronic organ injury independent of the initial insult, destroying tissue architecture and driving organ failure. Here we discover a population of profibrotic macrophages marked by expression of Spp1, Fn1, and Arg1 (termed Spp1 macrophages), which expands after organ injury. Using an unbiased approach, we identify the chemokine (C-X-C motif) ligand 4 (CXCL4) to be among the top upregulated genes during profibrotic Spp1 macrophage differentiation. In vitro and in vivo studies show that loss of Cxcl4 abrogates profibrotic Spp1 macrophage differentiation and ameliorates fibrosis after both heart and kidney injury. Moreover, we find that platelets, the most abundant source of CXCL4 in vivo, drive profibrotic Spp1 macrophage differentiation. Single nuclear RNA sequencing with ligand-receptor interaction analysis reveals that macrophages orchestrate fibroblast activation via Spp1, Fn1, and Sema3 crosstalk. Finally, we confirm that Spp1 macrophages expand in both human chronic kidney disease and heart failure.
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Adult human kidney organoids originate from CD24 + cells and represent an advanced model for adult polycystic kidney disease. Nat Genet 2022; 54:1690-1701. [PMID: 36303074 PMCID: PMC7613830 DOI: 10.1038/s41588-022-01202-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 09/09/2022] [Indexed: 11/09/2022]
Abstract
Adult kidney organoids have been described as strictly tubular epithelia and termed tubuloids. While the cellular origin of tubuloids has remained elusive, here we report that they originate from a distinct CD24+ epithelial subpopulation. Long-term-cultured CD24+ cell-derived tubuloids represent a functional human kidney tubule. We show that kidney tubuloids can be used to model the most common inherited kidney disease, namely autosomal dominant polycystic kidney disease (ADPKD), reconstituting the phenotypic hallmark of this disease with cyst formation. Single-cell RNA sequencing of CRISPR-Cas9 gene-edited PKD1- and PKD2-knockout tubuloids and human ADPKD and control tissue shows similarities in upregulation of disease-driving genes. Furthermore, in a proof of concept, we demonstrate that tolvaptan, the only approved drug for ADPKD, has a significant effect on cyst size in tubuloids but no effect on a pluripotent stem cell-derived model. Thus, tubuloids are derived from a tubular epithelial subpopulation and represent an advanced system for ADPKD disease modeling.
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Deep learning-based molecular morphometrics for kidney biopsies. JCI Insight 2021; 6:144779. [PMID: 33705360 PMCID: PMC8119189 DOI: 10.1172/jci.insight.144779] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 02/24/2021] [Indexed: 12/21/2022] Open
Abstract
Morphologic examination of tissue biopsies is essential for histopathological diagnosis. However, accurate and scalable cellular quantification in human samples remains challenging. Here, we present a deep learning-based approach for antigen-specific cellular morphometrics in human kidney biopsies, which combines indirect immunofluorescence imaging with U-Net-based architectures for image-to-image translation and dual segmentation tasks, achieving human-level accuracy. In the kidney, podocyte loss represents a hallmark of glomerular injury and can be estimated in diagnostic biopsies. Thus, we profiled over 27,000 podocytes from 110 human samples, including patients with antineutrophil cytoplasmic antibody-associated glomerulonephritis (ANCA-GN), an immune-mediated disease with aggressive glomerular damage and irreversible loss of kidney function. We identified previously unknown morphometric signatures of podocyte depletion in patients with ANCA-GN, which allowed patient classification and, in combination with routine clinical tools, showed potential for risk stratification. Our approach enables robust and scalable molecular morphometric analysis of human tissues, yielding deeper biological insights into the human kidney pathophysiology.
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Collaborative study for the validation of cell line assays for in-process toxicity and antigenicity testing of Clostridium septicum vaccine antigens - Part 2: Optimisation of cell line assays. PHARMEUROPA BIO & SCIENTIFIC NOTES 2021; 2021:101-156. [PMID: 34078535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
During the production of clostridial vaccines large numbers of mice are used for various in-process control tests. Replacement in vitro assays had been developed for the testing of the toxins and toxoids of several clostridial species, but none of these assays had been assessed in an international collaborative study. Under the common aegis of the European Partnership for Alternative Approaches to Animal Testing (EPAA) and of the European Directorate for the Quality of Medicines & HealthCare (EDQM), a project on clostridial vaccines for veterinary use was started as part of the EDQM-co-ordinated Biological Standardisation Programme (BSP). Within the framework of this project (coded BSP130) a collaborative study was organised to evaluate Vero cell-based alternative methods to the current mouse tests used to measure: i) the toxicity of Clostridium septicum toxin, ii) the absence of toxicity of C. septicum toxoid and iii) the antigenicity of C. septicum toxoid. The principal aims of the study were to determine the repeatability and reproducibility of the in vitro assays and to demonstrate concordance of the in vitro and current in vivo tests. The study results demonstrated good concordance, but the information gathered through the study (later on called Part 1) and the participants' workshop prompted the extension of the project in order to further optimise the in vitro protocols and improve their repeatability and reproducibility, which were comparable to but not better than those of the in vivo assays in Part 1. The 3 in vitro assays to be optimised in the extension of the BSP130 project were : i) the in vitro toxin neutralisation equivalence plus (TNE+), as a replacement for the in vivo minimum lethal dose (MLD) test for quantification of the toxicity of toxin; ii) the in vitro MLD, as a replacement for the in vivo MLD test for detection of residual toxicity associated with toxoid; iii) the in vitro total combining power (TCP), as a replacement for the in vivo TCP test for quantification of the antigenicity of toxoid. At this point, the Analytical Method Transfer Laboratory of Ceva-Phylaxia (Hungary), supported by the project management team, developed suitable SOPs for the 3 in vitro assays. These optimised methods were further assessed in BSP130 through a second international collaborative study (Part 2) aimed at defining repeatability and reproducibility in different laboratories and determining the levels of improvement compared with the original in vivo tests and the initial in vitro assays used in Part 1 of the project. Fourteen laboratories, comprising 4 public sector and 10 manufacturers' medicines control laboratories, from 11 countries participated in the collaborative Part 2 study, each testing 6 different C. septicum toxins and 6 C. septicum toxoids. Improved repeatability and reproducibility were observed for the optimised assays. The results of this study confirm the suitability of these assays for in-process control of C. septicum vaccines, with better repeatability and reproducibility than their in vivo equivalents. It is expected that, with appropriate minor changes and the use of relevant reagents, these optimised in vitro assays could be used not only for the assessment of C. septicum toxins and toxoids but for all cytotoxin-based clostridial antigens. The development and implementation of such in vitro assays would offer a great opportunity to significantly reduce animal usage, shorten the duration of QC test procedures and increase the precision of toxicity and antigenicity assays in clostridial veterinary vaccine in-process control. This would also provide more accurate and reproducible dosing of antigens in the final vaccine products, help to promote compendial acceptance and to proffer a basis for improved international harmonisation across this area of product testing.
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Abstract
Aim of Study The present study was planned to analyze serum heme oxygenase-1 levels in osteosarcoma patients. Materials and Methods Twenty five histopathologically confirmed cases of osteosarcoma localized without metastasis of all the ages attending the Orthopedic Clinics were included in the study group and twenty five patients having musculoskeletal pain (age and sex matched) served as control. Five ml of venous blood was collected aseptically from antecubital vein and serum was be separated by centrifugation and analyzed the same day. Routine biochemistry investigations were performed as per standard enzymatic methods by autoanalyzer. Serum Heme oxygenase-1 was analyzed by enzyme-linked immunosorbent assay. Results In osteosarcoma patients, serum HO-1 levels were increased as compared to patients having musculoskeletal pain (P < 0.05). Workers have found that HO-1 induction in prostate cancer cell lines (PC3) cells restored the proliferation of osteoblasts, which was inhibited during co-culture with parental prostate cancer cell line PC3 cells. However, no concrete data are available on blood levels of HO in osteosarcoma. Major role of HO-1 is the protection against oxidative injury, additionally, it regulates cell proliferation, modulates inflammatory response and facilitates angiogenesis. Conclusion Findings of the present study suggests that pharmacological agents that regulate HO activity or HO-1 gene silencing may become powerful tools for preventing the onset or progression of various cancers and sensitize them to anticancer therapies.
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Vitamin K2 Needs an RDI Separate from Vitamin K1. Nutrients 2020; 12:E1852. [PMID: 32575901 PMCID: PMC7353270 DOI: 10.3390/nu12061852] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/16/2020] [Accepted: 06/17/2020] [Indexed: 02/06/2023] Open
Abstract
Vitamin K and its essential role in coagulation (vitamin K [Koagulation]) have been well established and accepted the world over. Many countries have a Recommended Daily Intake (RDI) for vitamin K based on early research, and its necessary role in the activation of vitamin K-dependent coagulation proteins is known. In the past few decades, the role of vitamin K-dependent proteins in processes beyond coagulation has been discovered. Various isoforms of vitamin K have been identified, and vitamin K2 specifically has been highlighted for its long half-life and extrahepatic activity, whereas the dietary form vitamin K1 has a shorter half-life. In this review, we highlight the specific activity of vitamin K2 based upon proposed frameworks necessary for a bioactive substance to be recommended for an RDI. Vitamin K2 meets all these criteria and should be considered for a specific dietary recommendation intake.
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Initiation and Propagation of Vascular Calcification Is Regulated by a Concert of Platelet- and Smooth Muscle Cell-Derived Extracellular Vesicles. Front Cardiovasc Med 2018; 5:36. [PMID: 29682509 PMCID: PMC5897433 DOI: 10.3389/fcvm.2018.00036] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 03/26/2018] [Indexed: 12/20/2022] Open
Abstract
The ageing population continues to suffer from its primary killer, cardiovascular disease (CVD). Despite recent advances in interventional medicinal and surgical therapies towards the end of the 20th century, the epidemic of cardiovascular disease has not been halted. Yet, rather than receding globally, the burden of CVD has risen to become a top cause of morbidity and mortality worldwide. Most CVD arises from thrombotic rupture of an atherosclerotic plaque, the pathologic thickening of coronary and carotid artery segments and subsequent distal ischemia in heart or brain. In fact, one-fifth of deaths are directly attributable to thrombotic rupture of a vulnerable plaque. Atherosclerotic lesion formation is caused by a concert of interactions between circulating leukocytes and platelets, interacting with the endothelial barrier, signalling into the arterial wall by the release of cytokines and extracellular vesicles (EVs). Both platelet- and cell-derived EVs represent a novel mechanism of cellular communication, particularly by the transport and transfer of cargo and by reprogramming of the recipient cell. These interactions result in phenotypic switching of vascular smooth muscle cells (VSMCs) causing migration and proliferation, and subsequent secretion of EVs. Loss of VSMCs attracts perivascular Mesenchymal Stem Cells (MSCs) from the adventitia, which are a source of VSMCs and contribute to repair after vascular injury. However, continuous stress stimuli eventually switch phenotype of cells into osteochondrogenic VSMCs facilitating vascular calcification. Although Virchow’s triad is over 100 years old, it is a reality that is accurate today. It can be briefly summarised as changes in the composition of blood (platelet EVs), alterations in the vessel wall (VSMC phenotypic switching, MSC infiltration and EV release) and disruption of blood flow (atherothrombosis). In this paper, we review the latest relevant advances in the identification of extracellular vesicle pathways as well as VSMCs and pericyte/MSC phenotypic switching, underlying vascular calcification.
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p-Hexafluoroisopropanol phenyl functionalized graphene for QCM based detection of dimethyl methylphosphonate, a simulant of the nerve agent sarin. RSC Adv 2018; 8:8240-8245. [PMID: 35541990 PMCID: PMC9078545 DOI: 10.1039/c7ra12272a] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 01/19/2018] [Indexed: 11/21/2022] Open
Abstract
The hexafluoroisopropanol moiety was grafted onto graphene and used as a sensing layer for the detection of a nerve agent simulant using QCM.
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Cellular strain avoidance is mediated by a functional actin cap - observations in an Lmna-deficient cell model. J Cell Sci 2017; 130:779-790. [PMID: 28062850 DOI: 10.1242/jcs.184838] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 12/29/2016] [Indexed: 01/18/2023] Open
Abstract
In adherent cells, the relevance of a physical mechanotransduction pathway provided by the perinuclear actin cap stress fibers has recently emerged. Here, we investigate the impact of a functional actin cap on the cellular adaptive response to topographical cues and uniaxial cyclic strain. Lmna-deficient fibroblasts are used as a model system because they do not develop an intact actin cap, but predominantly form a basal layer of actin stress fibers underneath the nucleus. We observe that topographical cues induce alignment in both normal and Lmna-deficient fibroblasts, suggesting that the topographical signal transmission occurs independently of the integrity of the actin cap. By contrast, in response to cyclic uniaxial strain, Lmna-deficient cells show a compromised strain avoidance response, which is completely abolished when topographical cues and uniaxial strain are applied along the same direction. These findings point to the importance of an intact and functional actin cap in mediating cellular strain avoidance.
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The vaccines consistency approach project: an EPAA initiative. PHARMEUROPA BIO & SCIENTIFIC NOTES 2015; 2015:30-56. [PMID: 26830158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The consistency approach for release testing of established vaccines promotes the use of in vitro, analytical, non-animal based systems allowing the monitoring of quality parameters during the whole production process. By using highly sensitive non-animal methods, the consistency approach has the potential to improve the quality of testing and to foster the 3Rs (replacement, refinement and reduction of animal use) for quality control of established vaccines. This concept offers an alternative to the current quality control strategy which often requires large numbers of laboratory animals. In order to facilitate the introduction of the consistency approach for established human and veterinary vaccine quality control, the European Partnership for Alternatives to Animal Testing (EPAA) initiated a project, the "Vaccines Consistency Approach Project", aiming at developing and validating the consistency approach with stakeholders from academia, regulators, OMCLs, EDQM, European Commission and industry. This report summarises progress since the project's inception.
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The Production of Polyclonal Antibodies in Laboratory Animals. The Report and Recommendations of ECVAM Workshop 35. Altern Lab Anim 2014; 27:79-102. [PMID: 25423403 DOI: 10.1177/026119299902700106] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This is the report of the thirty-fifth of a series of workshops organised by the European Centre for the Validation of Alternative Methods (ECVAM). ECVAM's main goal, as defined in 1993 by its Scientific Advisory Committee, is to promote the scientific and regulatory acceptance of alternative methods which are of importance to the biosciences and which reduce, refine or replace the use of laboratory animals. One of the first priorities set by ECVAM was the implementation of procedures which would enable it to become well informed about the state-of-the-art of non-animal test development and validation, and the potential for the possible incorporation of alternative tests into regulatory procedures. It was decided that this would be best achieved by the organisation of ECVAM workshops on specific topics, at which small groups of invited experts would review the current status of various types of in vitro tests and their potential uses, and make recommendations about the best ways forward (1). This joint ECVAM/FELASA (Federation of European Laboratory Animal Science Associations) workshop on The Immunisation of Laboratory Animals for the Production of Polyclonal Antibodies was held in Utrecht (The Netherlands), on 20-22 March 1998, under the co-chairmanship of Coenraad Hendriksen (RIVM, Bilthoven, The Netherlands) and Wim de Leeuw (Inspectorate for Health Protection, The Netherlands). The participants, all experts in the fields of immunology, laboratory animal science, or regulation, came from universities, industry and regulatory bodies. The aims of the workshop were: a) to discuss and evaluate current immunisation procedures for the production of polyclonal antibodies (including route of injection, animal species and adjuvant ); and b) to draft recommendations and guidelines to improve the immunisation procedures, with regard both to animal welfare and to the optimisation of immunisation protocols. This report summarises the outcome of the discussions and includes a number of recommendations and a set of draft guidelines (included in Appendix 1).
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Abstract
Non-puerperal acute inversion of uterus is a rare complication that occurs as a complication of intra uterine tumors, especially big sub mucous leiomyoma. It is so rare that many gynecologists may not encounter such a case in their life time professional carrier. This condition causes severe pain, vaginal bleeding and shock. Management consists of manual reposition through cervical ring or surgical corrective measures. We report a case of acute uterine inversion in a 42 years lady due to big sub mucous fibroid. This case was initially managed by vaginal myomectomy then uterus was repositioned by Haultain’s technique, which was abdominal hysterectomy. DOI: http://dx.doi.org/10.3126/njog.v9i1.11190 NJOG 2014 Jan-Jun; 2(1):58-60
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Narrowband high-fidelity all-fibre source of heralded single photons at 1570 nm. OPTICS EXPRESS 2009; 17:6156-6165. [PMID: 19365438 DOI: 10.1364/oe.17.006156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
An all-fibre heralded single photon source operating at 1570 nm has been demonstrated. The device generates correlated photon pairs, widely spaced in frequency, through four-wave mixing in a photonic crystal fibre. Separation of the pair photons and narrowband filtering is all achieved in fibre. The output heralded single photon rate was 9.2 x 10(4) per second, with a counts-to-accidentals ratio of 10.4 and a heralding fidelity of 52 %. Furthermore, narrowband filtering ensured that the output single photon state was near time-bandwidth limited with a coherence length of 4 ps. Such a source is well suited to quantum information processing applications.
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Nonclassical 2-photon interference with separate intrinsically narrowband fibre sources. OPTICS EXPRESS 2009; 17:4670-4676. [PMID: 19293896 DOI: 10.1364/oe.17.004670] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In this paper, we demonstrate a source of photon pairs based on four-wave-mixing in photonic crystal fibres. Careful engineering of the phase matching conditions in the fibres enables us to create photon pairs at 597 nm and 860 nm in an intrinsically factorable state showing no spectral correlations. This allows for heralding one photon in a pure state and hence renders narrow band filtering obsolete. The source is narrow band, bright and achieves an overall detection efficiency of up to 21% per photon. For the first time, a Hong-Ou-Mandel interference with unfiltered photons from separate fibre sources is presented.
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Evaluation of two serological methods for potency testing of whole cell pertussis vaccines. PHARMEUROPA BIO 2008; 2008:7-18. [PMID: 19220977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The European Pharmacopoeia (Ph. Eur.) and the World Health Organization (WHO) require the performance of extensive quality control testing including a potency test before a vaccine batch is released for human use. Whole cell pertussis (wP) vaccine potency is assessed by a mouse protection test (MPT) based on the Kendrick test. This test compares the vaccine dose necessary to protect 50% of mice against the effect of a lethal intracerebral dose of Bordetella pertussis and the dose of a suitable reference vaccine needed to give the same protection level. Due to the large variability in the results of this test and the severe distress which is inflicted on the many animals involved, its replacement by an alternative method is highly desirable. At the initiative of the European Directorate for the Quality of Medicines and HealthCare (EDQM) of the Council of Europe, in collaboration with the WHO and the In-vitro toxicology Unit/European Centre for the Validation of Alternative Methods (ECVAM) of the European Commission (EC) Joint Research Centre-Institute for Health and Consumer Protection (JRC-IHCP), wP vaccine specialists from all over the world were invited to present an overview of candidate alternatives at a symposium organised in Geneva (Switzerland) in March 2005. Although no alternative method was found suitable for immediate implementation of batch potency control, the Pertussis Serological Potency Test (PSPT), initially developed in mice and recently transferred to guinea pigs (gps), was identified as a model of interest. Using the PSPT in gps to test several components of combined vaccines such as Diphtheria-Tetanus-wP vaccines in the same animal series would allow further implementation of the European 3Rs policy to batch potency control, by additional method refinement and reduction of animal use. The present study evaluated 2 features of the serological response to wP vaccination: 1) the overall antibody response as measured by a "whole cell" ELISA (PSPT-wC-ELISA) which uses the B. pertussis 18323 challenge strain prescribed for the MPT to coat the assay plates and 2) the functional neutralising antibodies to pertussis toxin (PT, one of the main virulence factors of B. pertussis), as measured by the Chinese Hamster Ovary (CHO) cell assay. The results showed that 1) the gp model can be used for wP vaccine potency testing; 2) despite good repeatability and precision, the CHO cell assay did not generate results comparable to the MPT. Moreover, the CHO cell assay showed significant differences in the ability of wP vaccines to induce neutralising anti-PT antibodies, which did not correlate to the overall antibody response evaluated by PSPT-wC-ELISA; 3) comparable potencies were obtained in the MPT and the PSPT-wC-ELISA. This study, supported by the previous ones correlating the PSPT-wC-ELISA in mice with the MPT, confirms that PSPT-wC-ELISA in gps is a promising approach for batch release potency testing of wP vaccines for which consistency in production has already been demonstrated by the MPT. However, a large scale validation study is required prior to the adoption of PSPT-wC-ELISA as a compendial reference method for wP vaccines batch release control.
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Amplitude and phase modulation of time-energy entangled two-photon states. OPTICS EXPRESS 2008; 16:16452-16458. [PMID: 18852751 DOI: 10.1364/oe.16.016452] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Accepted: 09/24/2008] [Indexed: 05/26/2023]
Abstract
We experimentally demonstrate amplitude and phase modulation of a time-energy entangled two-photon wave function. The entangled photons are produced by spontaneous parametric down-conversion, spectrally dispersed in an prism compressor, modulated in amplitude and/or phase, and detected in coincidence by sum-frequency generation. First, we present a Fourier optical analysis of the optical setup yielding an analytic expression for the resulting field distribution at the exit plane of the shaping apparatus. We then introduce amplitude and/or phase shaping and present results which can only be obtained through a combination of the two. Specifically, we use a shaper-based interferometer to measure the two-photon interference of an almost bandwidth-limited two-photon wave function.
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Synthesis of Hydroxy and Methoxy Perylene Quinones, Their Spectroscopic and Computational Characterization, and Their Antiviral Activity¶. Photochem Photobiol 2007. [DOI: 10.1111/j.1751-1097.2005.tb01464.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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ECVAM key area ecotoxicology: Summary of activities and future perspectives. Comp Biochem Physiol A Mol Integr Physiol 2007. [DOI: 10.1016/j.cbpa.2007.01.076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Experimental and Theoretical Investigations of Solvation Dynamics of Ionic Fluids: Appropriateness of Dielectric Theory and the Role of DC Conductivity. J Phys Chem A 2006; 110:8623-6. [PMID: 16836422 DOI: 10.1021/jp062936l] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An analysis is provided of the subnanosecond dynamic solvation of ionic liquids in particular and ionic solutions in general. It is our hypothesis that solvation relaxation in ionic fluids, in the nonglassy and nonsupercooled regimes, can be understood rather simply in terms of the dielectric spectra of the solvent. This idea is suggested by the comparison of imidazolium ionic liquids with their pure organic counterpart, butylimidazole (J. Phys. Chem. B 2004, 108, 10245-10255). It is borne out by a calculation of the solvation correlation time from frequency dependent dielectric data for the ionic liquid, ethylammonium nitrate, and for the electrolyte solution of methanol and sodium perchlorate. Very good agreement is obtained between these theoretically calculated solvation relaxation functions and those obtained from fluorescence upconversion spectroscopy. Our comparisons suggest that translational motion of ions may not be the predominant factor in short-time solvation of ionic fluids and that many tools and ideas about solvation dynamics in polar solvents can be adapted to ionic fluids.
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Synthesis of hydroxy and methoxy perylene quinones, their spectroscopic and computational characterization, and their antiviral activity. Photochem Photobiol 2005; 81:924-33. [PMID: 15884972 DOI: 10.1562/2004-11-23-ra-378] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Hydroxy and methoxy perylene quinones are synthesized in an attempt to isolate the essential spectroscopic and biological features of light-induced antiviral agents such as hypericin and hypocrellin. Unlike their naturally occurring counterparts, these synthetic quinones bear the carbonyl, hydroxyl, and methoxy groups in the "bay region." The hydroxy and methoxy compounds have rich absorption spectra with broad features in the visible (approximately 450-800 nm) and relatively more intense and narrow features at wavelengths < or = 350 nm. High-level ab initio quantum mechanical calculations assign the features in the absorption spectra to electronic transitions from S0 to S2 and to higher-lying electronic states. The calculations indicate that in the ground state the trans dihydroxy isomer is 12.5 kcal/mol lower in energy than the cis dihydroxy isomer and is thus the only species present. The lowest-energy trans methoxy ground state isomer and the lowest-energy cis methoxy ground state isomer are found to be degenerate. An additional cis methoxy isomer 6.3 kcal/mol higher in energy than the global minimum is assumed to contribute to the spectrum and is also considered. Finally, the synthetic compounds exhibit similar light-induced antiviral activity to each other, but significantly less than that of hypericin.
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Abstract
The photophysics of hypericin have been studied in its complex with two different isoforms, A1-1 and P1-1, of the protein glutathione S-transferase (GST). One molecule of hypericin binds to each of the two GST subunits. Comparisons are made with our previous results for the hypericin/human serum albumin complex (Photochem. Photobiol. 1999, 69, 633-645). Hypericin binds with high affinity to the GSTs: 0.65 microM for the A1-1 isoform and 0.51 microM for the P1-1 isoform (Biochemistry 2004, 43, 12761-12769). The photophysics and activity of hypericin are strongly modulated by the binding protein. Intramolecular hydrogen-atom transfer is suppressed in both cases. Most importantly, while there is significant singlet oxygen generation from hypericin bound to GST A1-1, binding to GST P1-1 suppresses singlet oxygen generation to almost negligible levels. The data are rationalized in terms of a simple model in which the hypericin photophysics depends entirely upon the decay of the triplet state by two competing processes, quenching by oxygen to yield singlet oxygen and ionization, the latter of these two are proposed to be modulated by A1-1 and P1-1.
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Abstract
Quantum communication requires the transfer of quantum states, or quantum bits of information (qubits), from one place to another. From a fundamental perspective, this allows the distribution of entanglement and the demonstration of quantum non-locality over significant distances. Within the context of applications, quantum cryptography offers a provably secure way to establish a confidential key between distant partners. Photons represent the natural flying qubit carriers for quantum communication, and the presence of telecommunications optical fibres makes the wavelengths of 1,310 nm and 1,550 nm particularly suitable for distribution over long distances. However, qubits encoded into alkaline atoms that absorb and emit at wavelengths around 800 nm have been considered for the storage and processing of quantum information. Hence, future quantum information networks made of telecommunications channels and alkaline memories will require interfaces that enable qubit transfers between these useful wavelengths, while preserving quantum coherence and entanglement. Here we report a demonstration of qubit transfer between photons of wavelength 1,310 nm and 710 nm. The mechanism is a nonlinear up-conversion process, with a success probability of greater than 5 per cent. In the event of a successful qubit transfer, we observe strong two-photon interference between the 710 nm photon and a third photon at 1,550 nm, initially entangled with the 1,310 nm photon, although they never directly interacted. The corresponding fidelity is higher than 98 per cent.
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A strategy to reduce the use of fish in acute ecotoxicity testing of new chemical substances notified in the European Union. Regul Toxicol Pharmacol 2005; 42:218-24. [PMID: 15949882 DOI: 10.1016/j.yrtph.2005.04.005] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2005] [Indexed: 11/28/2022]
Abstract
This study explores the applicability of a fish acute threshold (step-down) test approach for the assessment of new chemical substances notified in the EU. The proposed approach basically implies replacing the fish LC50 toxicity test with a simple acute threshold test and thus reducing the number of fish used and also costs. The fish test would be performed only at one concentration, the lowest between the EC50 concentrations obtained with previous testing with algae and daphnia. When fish would be more sensitive than algae and daphnia, testing with fish would be continued at lower concentrations (step-down). From step-down test results the LC50 value can be obtained by applying the binominal method of interpolation. These data can be used together with algal and daphnid data to provide the same Predicted No Effect Concentration values. The acute aquatic toxicity data used in this evaluation were extracted from the New Chemicals Database of the European Chemicals Bureau. The results show that 53.6-71.2% reduction of the number of fish used would be possible when applying this new testing strategy and suggest its use for regulatory purposes.
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Synthesis of Hydroxy and Methoxy Perylene Quinones, Their Spectroscopic and Computational Characterization, and Their Antiviral Activity¶. Photochem Photobiol 2005. [DOI: 10.1562/2004-11-23-ra-378r1.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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26
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Abstract
Understanding a protein's dielectric response requires both a theoretical model and a well-defined experimental system. The former has already been proposed by Song (J. Chem. Phys. 116, 9359 [2002]). We suggest that the latter is provided by the complex of coumarin 153 (C153) with apomyoglobin (ApoMb). C153 has been exhaustively studied and has proven to be an excellent probe of the solvation dynamics of polar solvents. Myoglobin is one of the most thoroughly studied proteins. Myoglobins from a wide range of species have been subject to X-ray structural analysis and site-directed mutagenesis. Here, we demonstrate the existence of a robust C153-apomyglobin system by means of molecular dynamics simulations, equilibrium binding studies using a Job's plot and capillary electrophoresis, circular dichroism and time-resolved fluorescence. The reorganization energy of C153 bound to ApoMb is compared with that of C153 in bulk solvent using the method of Jordanides et al. (J. Phys. Chem. B 103, 7995 [1999]).
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A Comparative Femtosecond Coherence Study of the Unligated Monomeric Hemeproteins Myoglobin and Leghemoglobin. J Phys Chem B 2003. [DOI: 10.1021/jp034828u] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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29
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Effects of Distal Pocket Mutations on the Geminate Recombination of NO with Leghemoglobin on the Picosecond Time Scale. J Phys Chem B 2003. [DOI: 10.1021/jp030106r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Implementation of three Rs alternatives in regulatory testing: possibilities and obstacles--the view of the validator. DEVELOPMENTS IN BIOLOGICALS 2003; 111:199-206. [PMID: 12678242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
After the establishment of the European Centre for the Validation of Alternative Methods (ECVAM) in 1993, the Scientific Advisory Committee (ESAC) decided at its first meeting that the implementation of the Three Rs in the production and quality control of biologicals should be one of ECVAMs priorities. In collaboration with experts, ECVAM has established guidelines on the pre-validation and validation of alternative toxicological methods, which are as applicable to alternative methods in the quality control of biologicals as they are to the testing of industrial chemicals. This paper explains the technical information which should be submitted to ECVAM to assess the readiness of a method for pre-validation, which is defined as a small-scale interlaboratory study to confirm that an optimised and transferable protocol is available. Where appropriate, a formal validation study is then conducted, to evaluate the scientific relevance and reliability of the test method.
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Progress in applying the three Rs of Russell & Burch to the testing of biological products. DEVELOPMENTS IN BIOLOGICALS 2003; 111:3-13. [PMID: 12678219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
The Three Rs (Reduction, Refinement, Replacement) concept of Russell & Burch in relation to humane laboratory animal experimentation is introduced, and special aspects concerning the testing of biologicals are outlined. The role of ECVAM in promoting the Three Rs in the European Union, by organising workshops and task forces, supporting conferences, and financing and/or participating in alternative test development, pre-validation and validation, is reviewed. Finally, examples are given of biologicals-related issues which deserve attention or greater focus.
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An ECVAM pre-validation study of physicochemical methods for predicting the biological potency of recombinant follicle stimulating hormone. DEVELOPMENTS IN BIOLOGICALS 2003; 111:149-52. [PMID: 12678234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
A pre-validation study was carried out, by six laboratories from six countries, of two physicochemical methods for predicting the in vivo biological potency of recombinant follicle stimulating hormone (follitropin beta), based on quantitative measures of isoform distribution by isoelectric focusing (IEF) and by capillary zone electrophoresis. Each of these methods was used to estimate the predicted bioactivities of four preparations of follitropin beta differing widely in their isoform compositions and specific bioactivities. The results of this study indicate that these methods, and particularly IEF, are transferable between laboratories, and produce results which are sufficiently accurate, precise, and reproducible, for them to be used for predicting the bioactivity of follitropin beta, especially if used with a standard preparation. The performance of these two methods for predicting the bioactivity of other types of follicle stimulating hormone, such as follitropin alfa, would need to be assessed separately, and might involve quantitatively different relationships between the responses measured in the physicochemical method and the bioactivities of preparations estimated by bioassay.
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Abstract
Large random bit-strings known as 'keys' are used to encode and decode sensitive data, and the secure distribution of these keys is essential to secure communications across the globe. Absolutely secure key exchange between two sites has now been demonstrated over fibre and free-space optical links. Here we describe the secure exchange of keys over a free-space path of 23.4 kilometres between two mountains. This marks a step towards accomplishing key exchange with a near-Earth orbiting satellite and hence a global key-distribution system.
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Three Rs potential in the development and quality control of immunobiologicals. ALTEX 2002; 18 Suppl 1:13-47. [PMID: 11854853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Immunobiologicals (vaccines, immunoglobulins and -sera) are considered to be the most cost-effective tools in the prevention of infectious diseases. Their importance will further increase due to various eradication programmes of the WHO and EU and the emergence of new infectious diseases or the re-emergence of diseases as diphtheria and tuberculosis. The production and quality control of immunobiologicals are regulated by monographs and guidelines, which are issued by international or national Pharmacopoeias (e.g. Ph. Eur.), international organisations (e.g. WHO, O.I.E.) and international regulatory bodies (e.g. EMEA). Their purpose is to assure the quality of the product, i.e. its safety and potency. It is estimated that 10 millions of laboratory animals are world-wide used for the production and quality control of immunobiologicals, of which 80% are needed for the safety and potency testing of the finished product (batch control). In recent decades, the use of Three Rs principles has been recognised by the above mentioned organisations and various national competent authorities and been incorporated into general monographs and guidelines. Several tests with questionable relevance have been deleted from Ph. Eur. monographs (e.g. abnormal toxicity test, extraneous agents testing of viral vaccines for carnivores) or are now carried out during production. Reduction of the number of animals used could be achieved by introducing single-dilution tests. A large number of immunochemical tests have been developed, which could completely or partly replace the use of animals for potency testing, however, only a few have been validated so far (e.g. ToBI and ELISA for potency testing of human and veterinary tetanus vaccine; ELISA for potency testing of erysipelas vaccine). Regulatory acceptance of validated alternative methods is still a critical step. In particular, the period between successful validation and the implementation appears to be far too long. Reasons for this could be the slow process of multinational agreement to revise pharmacopoeial monographs and guidelines, and the time-consuming and expensive production of sufficient reference material (antigen, sera etc) for the new test systems. The shift in the quality control concept from reliance on final batch testing to the concept of consistency of production offers the opportunity to reduce the numbers of animals being used and promote the use of alternative methods. Emphasis is put on a combination of in vitro tests, which could make it possible to monitor batch-to-batch consistency. This new concept of quality control is already in place for the new well-defined vaccines. In most cases, non-animal methods are used for monitoring consistency at critical steps in the production and testing of a vaccine. Whether the concept of consistency of production could be also applied to the conventional, less-defined products, should be investigated. Only little progress has been achieved with regard to international harmonisation. Most of the manufacturers produce for the world market, so harmonisation of the requirements or mutual recognition of tests would help to reduce the use of animals. There is agreement that for the time being animals will still be needed for the development of vaccines in order to gain best knowledge on the disease, the pathogen and the specific immune response, including: pathogenesis, identification of the protective antigens, the way the antigen is processed, the dynamics of the immune response, the induction of memory, and the selection of the best adjuvant. With regard to routine batch release of conventional products, a number of Three Rs approaches are already available and should further be developed and validated. Whereas routine batch release of new products should be based on in vitro methods already established during their development.
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Novel pyrogen tests based on the human fever reaction. The report and recommendations of ECVAM Workshop 43. European Centre for the Validation of Alternative Methods. European Centre for the Validation of Alternative Methods. Altern Lab Anim 2001; 29:99-123. [PMID: 11262757 DOI: 10.1177/026119290102900203] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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[The use of the R1-fish cell culture for detection of toxicity of waste water according to the German Waste Water Act]. ALTEX 2001; 7:17-26. [PMID: 11182901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
A fibroblastic cell line (R1) established in 1981 from the liver tissue of rainbow trout (Oncorhynchus mykiss) has been used for cytotoxicity testing of 301 waste water samples. The results obtained were compared with the results of the fish test performed parallely according to the German Waste Water Act. 54% of the samples proved to be neither fish toxic nor cytotoxic, 22% were fish and cytotoxic, 5% only fish toxic and 19% only cytotoxic. The results show that the R1-cell culture is useful to determine cytotoxicity of aquatic pollutants.
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Validation of alternative methods for the potency testing of vaccines. Altern Lab Anim 1998; 26:747-761. [PMID: 26042581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
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38
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Comments on appendix C of the national institutes of health response to the petition of the american anti-vivisection society to prohibit the use of animals in the production of monoclonal antibodies. Altern Lab Anim 1998; 26:549-554. [PMID: 26042436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
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Reducing the use of laboratory animals in biomedical research: problems and possible solutions. Altern Lab Anim 1998; 26:283-301. [PMID: 26042346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
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40
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Torsional changes in surgery for A-V phenomena. Indian J Ophthalmol 1997; 45:31-5. [PMID: 9475009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The role of torsion in the aetiopathogenesis of A-V phenomena has not been sufficiently emphasized. The success of vertical displacement of horizontal recti in correction of A or V has not been attributed to torsional changes. To evaluate this aspect, 21 cases of A or V phenomena were subjected to monocular recession-resection procedure with vertical shifting. Preoperative and postoperative torsional changes were evaluated on synoptophore (subjective torsion), and confirmed by fundus photography (objective torsion). Intorsion with A phenomenon was seen preoperatively in 5 of 8 cases which increased after surgery and was seen postoperatively in the other 3 cases also. Extorsion was observed in 5 of 13 cases pre operatively in 'V' phenomenon, but the changes in extorsion after surgery were less dramatic than those in intorsion. The oblique overactions were reduced in cases where they were present. Correction of A-V phenomena by torsion induced by vertical shifting of horizontal recti muscles is proposed, highlighting the role of torsion in A-V phenomena.
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Safe disposal of disposables. THE NATIONAL MEDICAL JOURNAL OF INDIA 1995; 8:145. [PMID: 7780364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Effect of monocular vertical displacement of horizontal recti in A V phenomena. Indian J Ophthalmol 1995; 43:9-11. [PMID: 8522373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Twenty-one cases of A V phenomena were subjected to monocular recession-resection procedure with vertical displacement of 8 mm in 11 cases and 5 mm in 10 cases. Both 8 mm and 5 mm shifts were found to be equally effective even in cases with mild or moderate cyclovertical muscle imbalance. However, in cases with oblique muscle dysfunction, residual vertical incomitance was observed in all such 13 cases and should therefore be avoided. Eight cases showed horizontal incomitance in extreme gazes and this was more with 8 mm shift compared to 5 mm shift.
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Detection of a baculovirus in the tiger prawn Penaeus monodon. ZENTRALBLATT FUR VETERINARMEDIZIN. REIHE B. JOURNAL OF VETERINARY MEDICINE. SERIES B 1989; 36:257-60. [PMID: 2763758 DOI: 10.1111/j.1439-0450.1989.tb00600.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In postlarval Penaeus monodon from a hatchery in Asia a baculovirus was detected in the epithelial cells of the hepatopancreas by electron microscopy. The baculovirus was identified as the Monodon baculovirus (MBV).
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Abstract
A prospective study was carried out, between January 1980 and March 1982, of all women who presented to the Breast Cancer Unit, Guy's Hospital, with a second primary breast cancer. The percentage of new simultaneous tumours detected clinically or by mammography was approximately 3 per cent. Routine mammographic screening of the contralateral breasts of patients with unilateral disease increased the rate of detection, fivefold, of simultaneous bilateral cancers. The incidence of nonsimultaneous bilateral disease was 7.6 second cancers per thousand patients at risk per year. The annual rate of occurrence of second primary cancers was a constant event and showed no trend either to increase or to decrease with follow-up. However, the risk of a nonsimultaneous second cancer was strongly correlated with age at first primary. Women who developed their first breast cancers under the age of 40 years had three times the risk of developing a second breast cancer compared with those who developed their first cancer after the age of 40. The risk of a second nonsimultaneous primary was 5.9 times that of the risk of occurrence of cancer in the first breast in the general female population.
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