1
|
Measurement of the Permanent Electric Dipole Moment of the Neutron. PHYSICAL REVIEW LETTERS 2020; 124:081803. [PMID: 32167372 DOI: 10.1103/physrevlett.124.081803] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 02/03/2020] [Indexed: 06/10/2023]
Abstract
We present the result of an experiment to measure the electric dipole moment (EDM) of the neutron at the Paul Scherrer Institute using Ramsey's method of separated oscillating magnetic fields with ultracold neutrons. Our measurement stands in the long history of EDM experiments probing physics violating time-reversal invariance. The salient features of this experiment were the use of a ^{199}Hg comagnetometer and an array of optically pumped cesium vapor magnetometers to cancel and correct for magnetic-field changes. The statistical analysis was performed on blinded datasets by two separate groups, while the estimation of systematic effects profited from an unprecedented knowledge of the magnetic field. The measured value of the neutron EDM is d_{n}=(0.0±1.1_{stat}±0.2_{sys})×10^{-26} e.cm.
Collapse
|
2
|
Prolactin receptors in Rip-cre cells, but not in AgRP neurones, are involved in energy homeostasis. J Neuroendocrinol 2017; 29. [PMID: 28378505 DOI: 10.1111/jne.12474] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 03/26/2017] [Accepted: 03/30/2017] [Indexed: 12/12/2022]
Abstract
Among its many functions, prolactin has been implicated in energy homeostasis, particularly during pregnancy and lactation. The arcuate nucleus is a key site in the regulation of energy balance. The present study aimed to examine whether arcuate nucleus neuronal populations involved in energy homeostasis are prolactin responsive and whether they can mediate the effects of prolactin on energy homeostasis. To determine whether Agrp neurones or Rip-Cre neurones are prolactin responsive, transgenic mice expressing the reporter td-tomato in Agrp neurones (td-tomato/Agrp-Cre) or Rip-Cre neurones (td-tomato/Rip-Cre) were treated with prolactin and perfused 45 minutes later. Brains were processed for double-labelled immunohistochemistry for pSTAT5, a marker of prolactin-induced intracellular signalling, and td-tomato. In addition, Agrp-Cre mice and Rip-Cre mice were crossed with mice in which the prolactin receptor gene (Prlr) was flanked with LoxP sites (Prlrlox/lox mice). The Prlrlox/lox construct was designed such that Cre-mediated recombination resulted in deletion of the Prlr and expression of green fluorescent protein (GFP) in its place. In td-tomato/Rip-Cre mice, prolactin-induced pSTAT5 was co-localised with td-tomato, indicating that there is a subpopulation of Rip-Cre neurones in the arcuate nucleus that respond to prolactin. Furthermore, mice with a specific deletion of Prlr in Rip-Cre neurones had lower body weights, increased oxygen consumption, increased running wheel activity and numerous cells in the arcuate nucleus had positive GFP staining indicating deletion of Prlr from Rip-Cre neurones. By contrast, no co-localisation of td-tomato and pSTAT5 was observed in td-tomato/Agrp-Cre mice after prolactin treatment. Moreover, Prlrlox/lox /Agrp-Cre mice had no positive GFP staining in the arcuate nucleus and did not differ in body weight compared to littermate controls. Overall, these results indicate that Rip-Cre neurones in the arcuate nucleus are responsive to prolactin and may play a role in the orexigenic effects of prolactin, whereas prolactin does not directly affect Agrp neurones.
Collapse
|
3
|
Abstract
Estrogen deficiency results in disruption of maxillary alveolar bone microarchitecture. Most of the actions of estrogen in long bones occur via estrogen receptor α (ERα). However, the function of ERα in the maxillary bone has not been defined. We aimed to investigate the role and underlying mechanisms of ERα in the physiological and mechanically induced alveolar bone remodeling in female and male mice. Wild-type (WT) and ERα−/− (ERKOα) mice were subjected to mechanically stimulated bone remodeling by inducing orthodontic tooth movement (OTM). The maxillary bone was analyzed using histomorphometric analysis, micro–computed tomography, quantitative polymerase chain reaction, and energy-dispersive spectroscopy. Bone marrow cells (BMCs) from WT and ERKOα mice were tested for their capacity to differentiate into osteoblasts and osteoclasts. Both male and female ERKOα mice exhibited marked reduction of alveolar bone mass and increased OTM. This response was associated with an increased number of osteoclasts and reduced number of apoptotic cells and osteoblasts in the periodontium and alveolar bone. Consistently, ERKOα mice exhibited lower levels of calcium in bone and increased expression of IL-33 (interleukin-33), TNF-α (tumor necrosis factor α), and IL-1β (interleukin-1β) and decreased expression of dentin matrix acidic phosphoprotein and alkaline phosphatase in periodontal tissues. Moreover, the differentiation of osteoclasts and osteoblasts in vitro was significantly higher in BMCs obtained from ERKOα. ERα is required to maintain the microarchitecture of maxillary alveolar bone. This process is linked to bone cell differentiation and apoptosis, as well as local production of inflammatory molecules such as IL-33, TNF-α, and IL-1β.
Collapse
|
4
|
Observation of Gravitationally Induced Vertical Striation of Polarized Ultracold Neutrons by Spin-Echo Spectroscopy. PHYSICAL REVIEW LETTERS 2015; 115:162502. [PMID: 26550870 DOI: 10.1103/physrevlett.115.162502] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Indexed: 06/05/2023]
Abstract
We describe a spin-echo method for ultracold neutrons (UCNs) confined in a precession chamber and exposed to a |B0|=1 μT magnetic field. We have demonstrated that the analysis of UCN spin-echo resonance signals in combination with knowledge of the ambient magnetic field provides an excellent method by which to reconstruct the energy spectrum of a confined ensemble of neutrons. The method takes advantage of the relative dephasing of spins arising from a gravitationally induced striation of stored UCNs of different energies, and also permits an improved determination of the vertical magnetic-field gradient with an exceptional accuracy of 1.1 pT/cm. This novel combination of a well-known nuclear resonance method and gravitationally induced vertical striation is unique in the realm of nuclear and particle physics and should prove to be invaluable for the assessment of systematic effects in precision experiments such as searches for an electric dipole moment of the neutron or the measurement of the neutron lifetime.
Collapse
|
5
|
Highly stable atomic vector magnetometer based on free spin precession. OPTICS EXPRESS 2015; 23:22108-22115. [PMID: 26368184 DOI: 10.1364/oe.23.022108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We present a magnetometer based on optically pumped Cs atoms that measures the magnitude and direction of a 1 μT magnetic field. Multiple circularly polarized laser beams were used to probe the free spin precession of the Cs atoms. The design was optimized for long-time stability and achieves a scalar resolution better than 300 fT for integration times ranging from 80 ms to 1000 s. The best scalar resolution of less than 80 fT was reached with integration times of 1.6 to 6 s. We were able to measure the magnetic field direction with a resolution better than 10 μrad for integration times from 10 s up to 2000 s.
Collapse
|
6
|
A Bell-Bloom experiment with polarization-modulated light of arbitrary duty cycle. OPTICS EXPRESS 2013; 21:15121-15130. [PMID: 23842299 DOI: 10.1364/oe.21.015121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We report on a study of polarization-modulation experiments on the 4 → 3 hyperfine component of the D1 transition in Cs vapor contained in a paraffin-coated cell. The laser beam's polarization was switched between left- and right-circular polarization at a rate of 200 Hz. Variations of the transmitted light power were recorded while varying the amplitude of a transverse magnetic field. The power shows electromagnetically induced transparency (EIT) resonances when the atomic Larmor frequency matches a harmonic of the modulation frequency. We made a quantitative study of the resonance amplitudes with square-wave modulations of various duty cycles, and find an excellent agreement with recent algebraic model predictions.
Collapse
|
7
|
Proton Structure from the Measurement of 2S-2P Transition Frequencies of Muonic Hydrogen. Science 2013; 339:417-20. [DOI: 10.1126/science.1230016] [Citation(s) in RCA: 581] [Impact Index Per Article: 52.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
|
8
|
|
9
|
Test of Lorentz invariance with spin precession of ultracold neutrons. PHYSICAL REVIEW LETTERS 2009; 103:081602. [PMID: 19792714 DOI: 10.1103/physrevlett.103.081602] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2009] [Indexed: 05/28/2023]
Abstract
A clock comparison experiment, analyzing the ratio of spin precession frequencies of stored ultracold neutrons and 199Hg atoms, is reported. No daily variation of this ratio could be found, from which is set an upper limit on the Lorentz invariance violating cosmic anisotropy field b perpendicular < 2 x 10(-20) eV (95% C.L.). This is the first limit for the free neutron. This result is also interpreted as a direct limit on the gravitational dipole moment of the neutron |gn| < 0.3 eV/c2 m from a spin-dependent interaction with the Sun. Analyzing the gravitational interaction with the Earth, based on previous data, yields a more stringent limit |gn| < 3 x 10(-4) eV/c2 m.
Collapse
|
10
|
Is it safe to discharge patients from accident and emergency using a rapid point of care Triple Cardiac Marker test to rule out acute coronary syndrome in low to intermediate risk patients presenting with chest pain? Eur J Intern Med 2008; 19:537-40. [PMID: 19013384 DOI: 10.1016/j.ejim.2008.01.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2007] [Revised: 10/15/2007] [Accepted: 01/20/2008] [Indexed: 11/30/2022]
Abstract
PURPOSE To determine whether patients presenting with chest pain who are at low to intermediate risk for ACS can safely be discharged from Accident and Emergency using Triple Cardiac Marker [TCM] [CK-MB, myoglobin, troponin I] without increasing risk and cost effective use of coronary care facilities. METHODS Retrospective review of consecutive patients presented to A&E between Dec 2003 and July 2004 was performed and these patients were prospectively followed for six months for future coronary events and hospital admissions. A total of 325 patients presented to A&E with chest pain that were at low to intermediate risk for ACS. Paired TCM and ECGs were performed 2 h apart and the results were used to determine whether hospital admission was required. Follow up data was collected from hospital records, hospital database, GPS and patient interviews. RESULTS 325 consecutive patients [225 men, 100 women; aged 18-97 years, median-68 years] were included in the study. Paired TCM was negative in 100 patients [30%] and they were discharged from A&E. The re-admission rate for this group of patients was 1% with ACS and no deaths from cardiac cause at six months. 36 [11%] had single TCM negative and were sent home with 3% re-admission rate with ACS and no death at six months. Subgroup analysis shows sensitivity and specificity of 85.7% and 96.5% respectively for TCM to diagnose ACS in this setting. CONCLUSION Almost one third of patients who presented with chest pain and low to intermediate probability of ACS were safely discharged from A&E following paired negative TCM. Six month re-admission rate with ACS in this group of patients was only 1% with no death. Therefore paired TCM can be used to safely discharge this group of patients. This marker has the potential to significantly reduce hospital admissions.
Collapse
|
11
|
Direct experimental limit on neutron-mirror-neutron oscillations. PHYSICAL REVIEW LETTERS 2007; 99:161603. [PMID: 17995237 DOI: 10.1103/physrevlett.99.161603] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Indexed: 05/25/2023]
Abstract
In case a mirror world with a copy of our ordinary particle spectrum would exist, the neutron n and its degenerate partner, the mirror neutron n', could potentially mix and undergo nn' oscillations. The interaction of an ordinary magnetic field with the ordinary neutron would lift the degeneracy between the mirror partners, diminish the n' amplitude in the n wave function and, thus, suppress its observability. We report an experimental comparison of ultracold neutron storage in a trap with and without superimposed magnetic field. No influence of the magnetic field is found and, assuming negligible mirror magnetic fields, a limit on the oscillation time taunn' > 103 s (95% C.L.) is derived.
Collapse
|
12
|
Hydrazine and amphetamine binding to amine oxidases: old drugs with new prospects. J Neural Transm (Vienna) 2007; 114:743-6. [PMID: 17406963 DOI: 10.1007/s00702-007-0681-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2006] [Accepted: 11/01/2006] [Indexed: 12/24/2022]
Abstract
Tranylcypromine (TCP), an amphetamine, is a reversible inhibitor of copper-containing amine oxidases. We have solved the structure of the complex of TCP with the amine oxidase from E. coli (ECAO) and shown that only the (+)-enantiomer of TCP binds. Kinetic studies on 2-phenylethylamine and TCP binding to wild-type ECAO and mutational variants fully support the model in which binding of the protonated amine is the first step in the catalytic cycle. Hydrazines are irreversible inhibitors of copper-containing amine oxidases. Binding of hydrazines leads to an adduct ("Adduct 1") with a chromophore at 430 nm which converts at higher pH to another adduct ("Adduct 2") with a chromophore at 520 nm. We have determined the structures of Adduct 1 and 2 for 2-hydrazinopyridine reacted with ECAO. It has been found that Adduct 1 corresponds to the hydrazone and azo tautomers whilst Adduct 2 corresponds to the azo tautomer coordinated to the active site copper. The implications of these results in developing more specific drugs are discussed.
Collapse
|
13
|
|
14
|
|
15
|
Structure of XPF endonuclease from A. pernix. Acta Crystallogr A 2005. [DOI: 10.1107/s0108767305090483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
16
|
|
17
|
Abstract
BACKGROUND AND OBJECTIVE Alexander disease is a slowly progressive CNS disorder that most commonly occurs in children. Until recently, the diagnosis could only be established by the histologic finding of Rosenthal fibers in brain specimens. Mutations in the glial fibrillary acidic protein (GFAP) gene have now been shown in a number of biopsy- or autopsy-proven patients with Alexander disease. A prospective study on patients suspected to have Alexander disease was conducted to determine the extent to which clinical and MRI criteria could accurately diagnose affected individuals, using GFAP gene sequencing as the confirmatory assay. METHODS Patients who showed MRI white matter abnormalities consistent with Alexander disease, unremarkable family history, normal karyotype, and normal metabolic screening were included in this study. Genomic DNA from patients was screened for mutations in the entire coding region, including the exon-intron boundaries, of the GFAP gene. RESULTS Twelve of 13 patients (approximately 90%) were found to have mutations in GFAP. Seven of those 12 patients presented in infancy with seizures and megalencephaly. Five were juvenile-onset patients with more variable symptoms. Two patients in the latter group were asymptomatic or minimally affected at the time of their initial MRI scan. The mutations were distributed throughout the gene, and all involved sporadic single amino acid heterozygous changes that changed the charge of the mutant protein. Four of the nine changes were novel mutations. CONCLUSIONS In symptomatic and asymptomatic patients with a predominantly frontal leukoencephalopathy by MRI, GFAP gene mutation analysis should be included in the initial diagnostic evaluation process for Alexander disease.
Collapse
|
18
|
Crystal structure of a gamma-herpes virus cyclin/cdk complex. Acta Crystallogr A 2000. [DOI: 10.1107/s0108767300022492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
19
|
Crystal structure of a gamma-herpesvirus cyclin-cdk complex. EMBO J 2000; 19:2877-88. [PMID: 10856233 PMCID: PMC203358 DOI: 10.1093/emboj/19.12.2877] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2000] [Revised: 04/20/2000] [Accepted: 04/20/2000] [Indexed: 01/19/2023] Open
Abstract
Several gamma-herpesviruses encode proteins related to the mammalian cyclins, regulatory subunits of cyclin-dependent kinases (cdks) essential for cell cycle progression. We report a 2.5 A crystal structure of a full-length oncogenic viral cyclin from gamma-herpesvirus 68 complexed with cdk2. The viral cyclin binds cdk2 with an orientation different from cyclin A and makes several novel interactions at the interface, yet it activates cdk2 by triggering conformational changes similar to cyclin A. Sequences within the viral cyclin N-terminus lock part of the cdk2 T-loop within the core of the complex. These sequences and others are conserved amongst the viral and cellular D-type cyclins, suggesting that this structure has wider implications for other cyclin-cdk complexes. The observed resistance of this viral cyclin-cdk complex to inhibition by the p27(KIP:) cdk inhibitor is explained by sequence and conformational variation in the cyclin rendering the p27(KIP:)-binding site on the cyclin subunit non-functional.
Collapse
|
20
|
|
21
|
Abstract
We studied 20 adult patients undergoing cardiac surgery. All received pancuronium as the sole neuromuscular blocking drug and no reversal agent was used. In the postoperative intensive care unit, mechanical ventilation was continued and patients were sedated with an infusion of propofol. Neuromuscular block was measured electromyographically at appropriate intervals until the train-of-four ratio (TOF) reached 0.8. At the time when the propofol infusion would normally be discontinued, 13 patients (65%) demonstrated a TOF of less than 0.8 (group median 0.23, interquartile range 0.11-0.6). Subsequently, the median time to achieve a TOF of 0.8 was 2 h 10 min (interquartile range 1 h-2 h 25 min). We found that if pancuronium was used during cardiac surgery, a significant proportion of patients remained partially paralysed when they would normally be allowed to emerge from anaesthesia in the ICU.
Collapse
|
22
|
Abstract
In a double-blinded study we examined the effect of supplementing patient-controlled morphine analgesia with intercostal nerve blockade to identify if this improved analgesia and reduced morphine requirements following renal transplantation. Fifty patients were randomized to receive unilateral intercostal nerve block with either 0.5% bupivacaine or saline to the lower five intercostal nerves. Each block was performed on the side of surgical incision following the completion of surgery. Patients receiving bupivacaine blockade reported reduced pain scores and used less morphine in the initial 4 h following renal transplantation, but did not demonstrate a significant reduction in overall pain scores, total 24 h morphine requirements, or sedation scores. Two patients developed a pneumothorax, neither of which were clinically apparent at the time of diagnosis, and only detected by chest radiography. A chest radiograph should therefore be considered mandatory after intercostal nerve blockade.
Collapse
|
23
|
Heparin prophylaxis and central neural blocking techniques. Anaesthesia 1997; 52:716. [PMID: 9244054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
24
|
Spinal haematoma and central neural blockade. Anaesthesia 1996; 51:803. [PMID: 8795347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
|
25
|
Abstract
Biologically active, mouse estrogen receptor hormone-binding domain (residues 313-599) overexpressed in Escherichia coli was purified to apparent homogeneity as a single component with a molecular mass of 32.831 kDa determined by electrospray ionization mass spectrometry, and was identical to the mass predicted from the amino acid sequence. The intact domain was isolated using a novel, rapid purification scheme without recourse to any chromatographic process. Pure ERhbd maintained both high affinity estradiol binding (at optimum pH 8.0) and specificity for estrogens and anti-estrogens. The steroid-binding domain sedimented as a 4S component in the presence or absence of bound [3H]estradiol and at 2S in the presence of urea. The molecular mass of the 4S steroid unoccupied ERhbd (from dynamic light scattering) was approximately 72 kDa, suggesting that the pure, unlabelled ERhbd formed homodimers. Steroid-labelled ERhbd electrofocussed as a single, acidic component at a pI of 5.6. Binding of ERhbd to [3H]estradiol was unaffected by Ca2+ and Mg2+ ions up to 1 mM but was significantly inhibited by Zn2+ ions at concentrations above 10 microM, an effect reversed by EDTA.
Collapse
|
26
|
Abstract
Two incidence have occurred in our hospital when a patient-controlled analgesia pump has accidentally delivered the whole contents of the syringe of diamorphine (60 mg) over a period of approximately 1 h. Electrical corruption of the pumps' program has been identified as the probable cause. All pumps of this type have been modified to prevent such occurrences.
Collapse
|
27
|
Pollen pool heterogeneity in jack pine (Pinus banksiana Lamb.): a problem for estimating outcrossing rates? TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 1992; 83:500-508. [PMID: 24202598 DOI: 10.1007/bf00226540] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/1990] [Accepted: 06/21/1991] [Indexed: 06/02/2023]
Abstract
Pollen pool heterogeneity, which violates an assumption of the mixed-mating model, is a major potential problem in measuring plant mating systems. In this study, isozyme markers were used to examine pollen pool heterogeneity in two natural populations of jack pine, Pinus banksiana Lamb., in northwestern Ontario, Canada. Population multilocus estimates of outcrossing rate ranged from 0.83 to 0.95 and differed significantly between populations. Single-tree multilocus outcrossing rates were found to be homogeneous among trees in both populations. Computer simulation studies indicated that a consanguineous pollen pool (pollen gametes related to the mother tree) was capable of biasing population outcrossing estimates downward. Random pollen pool heterogeneity (uncorrelated with maternal genotypes) did not appear to affect population outcrossing estimates in the simulations. Heterogeneity G-tests and Spearman rank tests showed that pollen pool heterogeneity existed in the two natural populations examined; however, it did not have a major effect on population outcrossing estimates, since the consanguineous pollen pool detected was probably a relatively minor component of the outcross pollen pool in both populations. In addition, heterogeneity G-tests were found to be not sensitive in detecting pollen pool heterogeneity caused by consanguineous pollen pool.
Collapse
|
28
|
The GLP large scale preparation of immunotoxins containing deglycosylated ricin A chain and a hindered disulfide bond. J Immunol Methods 1991; 142:223-30. [PMID: 1717600 DOI: 10.1016/0022-1759(91)90110-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The large scale preparation of two second generation immunotoxins containing murine monoclonal antibodies and deglycosylated ricin A chain is described. The procedure for the preparation of immunotoxins consists of the derivatization of antibody with SMPT and reduction of dgA with DTT followed by their reaction to establish a hindered interchain disulfide bond. The purification of the immunotoxin includes affinity chromatography on Blue-Sepharose to remove the free antibody and gel filtration on Sephacryl S-200HR to remove any high molecular weight material and free dgA. The two immunotoxins were prepared by GLP procedures and tested for yield, composition, purity, sterility and biological activity.
Collapse
|
29
|
Selective killing of malignant cells fey antibody-ricin conjugates (‘immunotoxins’). Eur J Pharmacol 1990. [DOI: 10.1016/0014-2999(90)91415-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
30
|
Inheritance and linkage relationships of allozymes of eastern white cedar (Thuja occidentalis) in northwestern Ontario. Genome 1989. [DOI: 10.1139/g89-435] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Allozyme variants of 12 enzyme systems were examined in seed tissues of eastern white cedar (Thuja occidentalis L.), using starch gel electrophoresis. Nine loci were polymorphic and deviation from a 1:1 segregation ratio was observed between two of three alleles at one locus (Mdh-1). Of the possible 36 locus-pair combinations, 23 could be tested for linkage. Significant linkage was detected for three pairs of loci (Aat-1/Mdh-1, Aat-1/Pgm, and Idh-2/Me). Trees jointly segregating for Aat-1 and Pgm fell into two classes, one with a low recombination frequency (9.1%) and the other with a higher recombination frequency (26.6%). An inversion polymorphism is a possible cause of this linkage heterogeneity observed among trees.Key words: allozymes, isozymes, inheritance, linkage, eastern white cedar, northern white cedar, Thuja occidentalis L., Cupressaceae.
Collapse
|
31
|
Evaluation of four CD22 antibodies as ricin A chain-containing immunotoxins for the in vivo therapy of human B-cell leukemias and lymphomas. Int J Cancer 1988; 42:792-7. [PMID: 3263328 DOI: 10.1002/ijc.2910420527] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Ricin A chain-containing immunotoxins (IT-As) specific for the human B-cell antigen, CD22, were prepared from 4 monoclonal antibodies (MAbs) or their Fab' fragments: RFB4, HD6, UV22-I and UV22-2. The ITs were tested for their ability to kill cells from the Burkitt lymphoma line, Daudi, the pre-B-cell leukemia line, NALM-6, and the myeloma cell line, ARH-77. Daudi expresses high levels of CD22, whereas NALM-6 and ARH-77 express low levels of CD22. The IgG-RFB4-A was highly toxic to all 3 cell lines; it killed 50% of the Daudi cells at a concentration of 1.2 x 10(-12) M and 50% of NALM-6 and ARH-77 cells at concentrations of 1.5 to 2.1 x 10(-11) M. IgG-RFB4-A was 10-30 times more toxic to Daudi cells than were the IgG-As constructed from the other 3 CD22 MAbs and 10 times more toxic than ricin itself. IT-As constructed from the Fab' fragments of the 4 CD22 antibodies were 2 to 5 times less toxic to Daudi cells than their IgG-A counterparts. Fab'-RFB4-A was twice as toxic to Daudi cells as ricin, whereas the other Fab'-As were about 7 times less toxic than ricin. Scatchard analyses of the binding of the radio-iodinated antibodies to Daudi cells showed that the intact RFB4 antibody bound 3-10 times more strongly than the other antibodies, whereas the Fab'-RFB4 bound 1.2 to 3.5 times more strongly than the Fab' fragments prepared from the other antibodies. Thus, the potent cytotoxic activity of the RFB4-As appears to derive, in part, from their superior binding affinity. Prior studies have shown that UV22-I and HD6 cross-react with certain normal human tissues lacking cells of B-cell lineage, whereas UV22-2 and RFB4 are B-cell-specific. This fact, together with its superior potency as an IT-A, suggests that RFB4 is the antibody of choice for preparing Fab'-As or IgG-As for in vivo therapy of human B-cell leukemias and lymphomas.
Collapse
|
32
|
Synthesis and quantitative structure-activity relationships of antiallergic 2-hydroxy-N-1H-tetrazol-5-ylbenzamides and N-(2-hydroxyphenyl)-1H-tetrazole-5-carboxamides. J Med Chem 1986; 29:538-49. [PMID: 2870188 DOI: 10.1021/jm00154a019] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The synthesis and antiallergic activity of a series of 2-hydroxy-N-1H-tetrazol-5-ylbenzamides and isomeric N-(2-hydroxyphenyl)-1H-tetrazole-5-carboxamides is described. A relationship between structure and intravenous antiallergic activity in the rat passive cutaneous anaphylaxis (PCA) test has been established using a Hansch/Free-Wilson model and used to direct studies toward potent derivatives. The contribution of physicochemical properties to activity is discussed. One member of this series, N-(3-acetyl-5-fluoro-2-hydroxyphenyl)-1H-tetrazole-5-carboxamide (3f), which was selected for further evaluation, has an ID50 value of 0.16 mg/kg po and is 130 times more potent than disodium cromoglycate (DSCG) on intravenous administration.
Collapse
|
33
|
A longitudinal analysis of patient characteristics at a private alcoholism hospital. JOURNAL OF STUDIES ON ALCOHOL 1983; 44:524-9. [PMID: 6645532 DOI: 10.15288/jsa.1983.44.524] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Trends in the sex, religious preference, marital status, number of children and age of patients seeking admission at a private alcoholism hospital from 1955 to 1980 are discussed.
Collapse
|
34
|
Changes in the copper centres of benzylamine oxidase from pig plasma during the catalytic cycle. Biochem Biophys Res Commun 1978; 83:1216-24. [PMID: 213067 DOI: 10.1016/0006-291x(78)91524-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
35
|
Three approaches to specialty courses OR nursing. Twin Cities nurses learn skills in classroom, lab. AORN J 1976; 24:900-5. [PMID: 1049538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
36
|
Abstract
The synthesis and antiallergic activity in the rat passive cutaneous anaphylactic reaction of a series of 2-phenyl-8-azapurin-6-ones are described. Early in the investigation, a linear free-energy equation was established in which the activity was related to the size and hydrogen bonding capacity of the ortho substituent in the phenyl ring. This relationship was used to provide guidance and limits for subsequent work leading to 2-o-propoxyphenyl-8-azapurin-6-one which is 40 times more potent than disodium cromoglycate. It is suggested that good antiallergic activity in this series is associated with coplanarity of the phenyl group with the azapurin-6-one which would be favored by a high degree of hydrogen bonding.
Collapse
|
37
|
|
38
|
Light-induced and related reactions of quinones. Part III. Light-induced reactions of some monosubstituted 1,4-benzoquinones. ACTA ACUST UNITED AC 1966. [DOI: 10.1039/j39660001627] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
39
|
767. Heterocyclic compounds of nitrogen. Part IX. The preparation of some cinnoline derivatives. ACTA ACUST UNITED AC 1964. [DOI: 10.1039/jr9640004046] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
40
|
|
41
|
218. Reducing reactions of tin(II) in aqeous solution. Part II. The reaction between tin(II) and vanadium(V) in dilute hydrochloric acid. ACTA ACUST UNITED AC 1962. [DOI: 10.1039/jr9620001137] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|