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Wallis G, Menke R, Chelton C. WORKPLACE FIELD TESTING OF A DISPOSABLE NEGATIVE PRESSURE HALF-MASK DUST RESPIRATOR (3M 8710). ACTA ACUST UNITED AC 2010. [DOI: 10.1080/15298669391355080] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Menke R, Wallis G. Detection of mercury in air in the presence of chlorine and water vapor. ACTA ACUST UNITED AC 2010; 41:120-4. [PMID: 15508486 DOI: 10.1080/15298668091424465] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Evidence is presented that low concentrations of mercury and chlorine vapor in air form reaction products. At constant mercury concentration the rate of formation increases with chlorine concentration and relative humidity. The mercury-chlorine compound as well as the vapor of elemental mercury are absorbed by Hopcalite or by KMnO4-H2SO4 scrubber solution. The compound can be separated from mercury vapor by its absorption in polyurethane or by filtration by means of Millipore aerosol membranes.
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Burgess-Limerick R, Krupenia V, Wallis G, Pratim-Bannerjee A, Steiner L. Directional control-response relationships for mining equipment. ERGONOMICS 2010; 53:748-757. [PMID: 20496241 DOI: 10.1080/00140131003675109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A variety of directional control-response relationships are currently found in mining equipment. Two experiments were conducted in a virtual environment to determine optimal direction control-response relationships in a wide variety of circumstances. Direction errors were measured as a function of control orientation (horizontal or vertical), location (left, front, right) and directional control-response relationships. The results confirm that the principles of consistent direction and visual field compatibility are applicable to the majority of situations. An exception is that fewer direction errors were observed when an upward movement of a horizontal lever or movement of a vertical lever away from the participants caused extension (lengthening) of the controlled device, regardless of whether the direction of movement of the control is consistent with the direction in which the extension occurs. Further, both the control of slew by horizontally oriented controls and the control of device movements in a frontal plane by the perpendicular movements of vertical levers were associated with relatively high rates of directional errors, regardless of the directional control-response relationship, and these situations should be avoided. STATEMENT OF RELEVANCE: The results are particularly applicable to the design of mining equipment such as drilling and bolting machines, and have been incorporated into MDG35.1 Guideline for bolting & drilling plant in mines (Industry & Investment NSW, 2010). The results are also relevant to the design of any equipment where vertical or horizontal levers are used to control the movement of equipment appendages, e.g. cranes mounted to mobile equipment and the like.
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Wallis G. On the spatio-temporal limits of retinal motion compensation, and why they are the undoing of temporal binding. J Vis 2010. [DOI: 10.1167/6.6.93] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Wallis G. Breaking multiple forms of view invariance. J Vis 2010. [DOI: 10.1167/7.9.334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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31
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Burmester A, Wallis G. Capacity limits for the detection of changing visual features. J Vis 2010. [DOI: 10.1167/6.6.58] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Carter O, Pettigrew J, Hasler F, Wallis G, Vollenweider F. Psilocybin slows binocular rivalry switching through serotonin modulation. J Vis 2010. [DOI: 10.1167/6.6.43] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Pollard JS, Taylor SE, Wallis G, Panchal SN, Egun AA. Bowel obstruction in the postpartum period as a result of caecal volvulus around a large uterine leiomyoma. J OBSTET GYNAECOL 2009; 29:673. [PMID: 19757285 DOI: 10.1080/01443610903100633] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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34
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Greig C, Spreckley K, Aspinwall R, Gillaspy E, Grant M, Ollier W, John S, Doherty M, Wallis G. Linkage to nodal osteoarthritis: quantitative and qualitative analyses of data from a whole-genome screen identify trait-dependent susceptibility loci. Ann Rheum Dis 2006; 65:1131-8. [PMID: 16504993 PMCID: PMC1798305 DOI: 10.1136/ard.2005.048165] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To identify susceptibility loci for nodal osteoarthritis. METHODS A genome screen at an average marker spacing of 9.29 cM was carried out on 558 people from 202 families, of whom 491 had nodal osteoarthritis. All genotyped people were graded for the incidence and severity of distal interphalangeal (DIP) nodes, and radiographs from 354 people were graded for joint-space narrowing (JSN) and osteophytes (OSTs). Age-regressed indices for DIP nodes, JSN and OSTs were calculated using these phenotypic data. Affected sibling pair (ASP) and quantitative trait analyses were carried out using MERLIN. RESULTS The data analysis identified suggestive linkage to loci on chromosomes 3 (for JSN and OST), 4 (for JSN), 8 (for DIP), 11 (for radiographic osteoarthritis) and 16 (for JSN). Both the ASP and quantitative analyses identified the loci on chromosomes 4 and 11. The loci on chromosomes 3 and 16 overlap with those previously identified for large-joint osteoarthritis. Of the loci identified by the quantitative analyses with the logarithm of the odds of linkage >1.5, two were linked to more than one trait, whereas nine were linked to single traits: one for DIP, six for JSN and two for OST. CONCLUSION The ASP and quantitative analyses of the cohort with nodal osteoarthritis suggest that multiple susceptibility loci for osteoarthritis influence the traits, which combine to form the osteoarthritis phenotype, and that these loci may not act exclusively on the joints of the hand.
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Eyre S, Roby P, Wolstencroft K, Spreckley K, Aspinwall R, Bayoumi R, Al-Gazali L, Ramesar R, Beighton P, Gleghorn L, Wallis G. Identification of a locus for a form of spondyloepiphyseal dysplasia on chromosome 15q26.1: exclusion of aggrecan as a candidate gene. J Med Genet 2005; 42:e34. [PMID: 15937074 PMCID: PMC1736074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
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36
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Wallis G. Linear models of simple cells: correspondence to real cell responses and space spanning properties. SPATIAL VISION 2002; 14:237-60. [PMID: 11817739 DOI: 10.1163/156856801753253573] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Despite their limitations, linear filter models continue to be used to simulate the receptive field properties of cortical simple cells. For theoreticians interested in large scale models of visual cortex, a family of self-similar filters represents a convenient way in which to characterise simple cells in one basic model. This paper reviews research on the suitability of such models, and goes on to advance biologically motivated reasons for adopting a particular group of models in preference to all others. In particular, the paper describes why the Gabor model, so often used in network simulations, should be dropped in favour of a Cauchy model, both on the grounds of frequency response and mutual filter orthogonality.
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Eyre S, Roby P, Wolstencroft K, Spreckley K, Aspinwall R, Bayoumi R, Al-Gazali L, Ramesar R, Beighton P, Wallis G. Identification of a locus for a form of spondyloepiphyseal dysplasia on chromosome 15q26.1: exclusion of aggrecan as a candidate gene. J Med Genet 2002; 39:634-8. [PMID: 12205105 PMCID: PMC1735219 DOI: 10.1136/jmg.39.9.634] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We have investigated a family with an autosomal dominant form of spondyloepiphyseal dysplasia (SED) characterised by short stature and severe premature degenerative arthropathy. Previous studies have excluded linkage between this condition and the locus for the type II collagen gene. Here we report the identification of linkage between this disorder and a locus on the long arm of chromosome 15 between markers D15S979 and D15S1004. According to current linkage maps and sequence data, this locus includes that of the aggrecan gene (AGC1). Our linkage data from the SED family show, however, that AGC1 maps to a locus that is proximal to D15S979. This proximal location for AGC1 is further supported by linkage data from a second family with an autosomal recessive form of multiple epiphyseal dysplasia that also maps to the SED locus. In both families AGC1 is therefore excluded as a candidate gene.
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Pace JM, Atkinson M, Willing MC, Wallis G, Byers PH. Deletions and duplications of Gly-Xaa-Yaa triplet repeats in the triple helical domains of type I collagen chains disrupt helix formation and result in several types of osteogenesis imperfecta. Hum Mutat 2001; 18:319-26. [PMID: 11668615 DOI: 10.1002/humu.1193] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Triple helix formation is a prerequisite for the passage of type I procollagen from the endoplasmic reticulum and secretion from the cell to form extracellular fibrils that will support mineral deposition in bone. Analysis of cDNA from 11 unrelated individuals with osteogenesis imperfecta (OI) revealed the presence of 11 novel, short in-frame deletions or duplications of three, nine, or 18 nucleotides in the helical coding regions of the COL1A1 and COL1A2 collagen genes. Triple helix formation was impaired, type I collagen alpha chains were post-translationally overmodified, and extracellular secretion was markedly reduced. With one exception, the obligate Gly-Xaa-Yaa repeat pattern of amino acids in the helical domains was not altered, but the Xaa- and Yaa position residues were out of register relative to the amino acid sequences of adjacent chains in the triple helix. Thus, the identity of these amino acids, in addition to third position glycines, is important for normal helix formation. These findings expand the known repertoire of uncommon in-frame deletions and duplications in OI, and provide insight into normal collagen biosynthesis and collagen triple helix formation.
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Wiebe MG, Karandikar A, Robson GD, Trinci AP, Candia JL, Trappe S, Wallis G, Rinas U, Derkx PM, Madrid SM, Sisniega H, Faus I, Montijn R, van den Hondel CA, Punt PJ. Production of tissue plasminogen activator (t-PA) in Aspergillus niger. Biotechnol Bioeng 2001; 76:164-74. [PMID: 11505386 DOI: 10.1002/bit.1156] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A protease-deficient strain of Aspergillus niger has been used as a host for the production of human tissue plasminogen activator (t-PA). In defined medium, up to 0.07 mg t-PA (g biomass)(-1) was produced in batch and fed-batch cultures and production was increased two- to threefold in two-phase batch cultures in which additional glucose was provided as a single pulse at the end of the first batch growth phase. Production was increased [up to 1.9 mg t-PA (g biomass)(-1)] by the addition of soy peptone to the defined medium. The rate of t-PA production in batch cultures supplemented with soy peptone (0.2 to 0.6 mg t-PA L(-1) h(-1)) was comparable to rates observed previously in high-producing mammalian or insect cell cultures. In glucose-limited chemostat culture supplemented with soy peptone, t-PA was produced at a rate of 0.7 mg t-PA L(-1) h(-1). Expression of t-PA in A. niger resulted in increased expression of genes (bipA, pdiA, and cypB) involved in the unfolded protein response (UPR). However, when cypB was overexpressed in a t-PA-producing strain, t-PA production was not increased. The t-PA produced in A. niger was cleaved into two chains of similar molecular weight to two-chain human melanoma t-PA. The two chains appeared to be stable for at least 16 h in culture supernatant of the host strain. However, in general, <1% of the t-PA produced in A. niger was active, and active t-PA disappeared from the culture supernatant during the stationary phase of batch cultures, suggesting that the two-chain t-PA may have been incorrectly processed or that initial proteolytic cleavage occurred within the proteolytic domain of the protein. Total t-PA (detected by enzyme-linked immunoassay) also eventually disappeared from culture supernatants, confirming significant extracellular proteolytic activity, even though the host strain was protease-deficient.
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White A, Wallis G. Endochondral ossification: a delicate balance between growth and mineralisation. Curr Biol 2001; 11:R589-91. [PMID: 11516962 DOI: 10.1016/s0960-9822(01)00359-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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41
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Wallis G. β-Galactofuranoside glycoconjugates on conidia and conidiophores of Aspergillus niger. FEMS Microbiol Lett 2001. [DOI: 10.1016/s0378-1097(01)00219-1] [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] Open
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Wallis G, Bülthoff HH. Effects of temporal association on recognition memory. Proc Natl Acad Sci U S A 2001; 98:4800-4. [PMID: 11287633 PMCID: PMC31914 DOI: 10.1073/pnas.071028598] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/1999] [Accepted: 01/18/2001] [Indexed: 11/18/2022] Open
Abstract
The influence of temporal association on the representation and recognition of objects was investigated. Observers were shown sequences of novel faces in which the identity of the face changed as the head rotated. As a result, observers showed a tendency to treat the views as if they were of the same person. Additional experiments revealed that this was only true if the training sequences depicted head rotations rather than jumbled views; in other words, the sequence had to be spatially as well as temporally smooth. Results suggest that we are continuously associating views of objects to support later recognition, and that we do so not only on the basis of the physical similarity, but also the correlated appearance in time of the objects.
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Wallis G. DNA discovery. Science 1999; 285:837. [PMID: 10454932 DOI: 10.1126/science.285.5429.835f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Stewart CA, Hyam K, Wallis G, Sang H, Robinson KA, Floyd RA, Kotake Y, Hensley K. Phenyl-N-tert-butylnitrone demonstrates broad-spectrum inhibition of apoptosis-associated gene expression in endotoxin-treated rats. Arch Biochem Biophys 1999; 365:71-4. [PMID: 10222040 DOI: 10.1006/abbi.1999.1159] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Systemic exposure to gram-negative bacterial substances such as lipopolysaccharide (LPS, or endotoxin) induces an uncontrolled, massive inflammatory reaction which culminates in multiple system organ failure and death. Septic shock often does not respond to corticosteroids; however, certain low-molecular-weight antioxidant compounds have been discovered to possess potent anti-inflammatory action, and some of these novel compounds can rescue animals from experimentally induced septic shock. Phenyl-N-tert-butylnitrone (PBN) is the archetype of the nitrone class of antioxidants which we have previously shown to suppress LPS-induced cytokine biosynthesis in vivo. Using a multiprobe ribonuclease protection assay, we now demonstrate the ability of PBN to suppress proapoptotic gene expression in the LPS-induced model of endotoxic shock. The broad-spectrum gene-suppressive affects of PBN are discussed in the context of inflammatory signal transduction and models are proposed to explain why certain antioxidants may also possess anti-inflammatory and antiapoptotic properties.
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Roby P, Eyre S, Worthington J, Ramesar R, Cilliers H, Beighton P, Grant M, Wallis G. Autosomal dominant (Beukes) premature degenerative osteoarthropathy of the hip joint maps to an 11-cM region on chromosome 4q35. Am J Hum Genet 1999; 64:904-8. [PMID: 10053028 PMCID: PMC1377811 DOI: 10.1086/302291] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Wright GD, Regan M, Deighton CM, Wallis G, Doherty M. Evidence for genetic anticipation in nodal osteoarthritis. Ann Rheum Dis 1998; 57:524-6. [PMID: 9849310 PMCID: PMC1752739 DOI: 10.1136/ard.57.9.524] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE Evidence was sought for genetic anticipation (disease occurring at an earlier age in subsequent generations, with increasing severity) in nodal osteoarthritis (NOA). METHODS Age at symptom onset and disease severity was compared within 30 parent/offspring pairs with NOA. Correlation between the offspring age of disease onset and the parental age at conception was also assessed. RESULTS The age at onset of nodal symptoms was earlier in the offspring (43 years (95% confidence intervals (CI) 38 to 47) v 61 (CI 58 to 65); mean difference 18 years (CI 13 to 22): p < 0.001) as was larger joint symptom onset (48 years (CI 41 to 55) v 67 (CI 61 to 73); mean difference 20 years (CI 13 to 27): p < 0.01). A negative correlation existed between age of offspring symptom onset and parental age at conception. Fifteen (50%) offspring had similar or more extensive disease than their parents. CONCLUSIONS These results suggest genetic anticipation occurs in NOA and if confirmed a search for trinucleotide repeats is warranted.
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Wallis G. Spatio-temporal influences at the neural level of object recognition. NETWORK (BRISTOL, ENGLAND) 1998; 9:265-278. [PMID: 9861989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In late 1988, Miyashita published work reporting recordings of single cells in the inferotemporal cortex of the macaque monkey (Miyashita 1988 Nature 335 817-20). He described the responses of neurons to a sequence of random fractal pattern images, and how many of the neurons tested were seen to respond strongly to a subset of the images on the basis of sequence presentation order, i.e. appearance in time, rather than their spatial similarity. In this work, I describe a local Hebb-like learning rule which in conjunction with a simple feedforward neural architecture is capable of replicating the type of temporal-order association apparent in the cells from which he made recordings. The paper also advances reasons for requiring such learning by describing its possible role in establishing transformation invariant representations of objects.
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Brackett DJ, Wallis G, Wilson MF, McCay PB. Spin trapping and electron paramagnetic resonance spectroscopy. Methods Mol Biol 1998; 108:15-25. [PMID: 9921512 DOI: 10.1385/0-89603-472-0:15] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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Abstract
A means for establishing transformation-invariant representations of objects is proposed and analyzed, in which different views are associated on the basis of the temporal order of the presentation of these views, as well as their spatial similarity. Assuming knowledge of the distribution of presentation times, an optimal linear learning rule is derived. Simulations of a competitive network trained on a character recognition task are then used t highlight the success of this learning rule in relation to simple Hebbian learning and to show that the theory can give accurate quantitative predictions for the optimal parameters for such networks.
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Tabatabaie T, Kotake Y, Wallis G, Jacob JM, Floyd RA. Spin trapping agent phenyl N-tert-butylnitrone protects against the onset of drug-induced insulin-dependent diabetes mellitus. FEBS Lett 1997; 407:148-52. [PMID: 9166889 DOI: 10.1016/s0014-5793(97)00327-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Insulin-dependent diabetes mellitus is an autoimmune disease believed to be caused by an inflammatory process in the pancreas leading to selective destruction of the beta-cells. Cytokines and nitric oxide (NO) have been shown to be involved in this destruction. Phenyl N-tert-butylnitrone (PBN) has demonstrated protective effects against several pathological conditions including ischemia-reperfusion injury and endotoxin-induced shock. We report here that PBN co-administration can prevent the onset of the STZ-induced diabetes in mice. PBN co-treatment inhibited the streptozotocin (STZ)-induced hyperglycemia, the elevation in the level of glycated hemoglobin and weight loss in the treated mice. Histological observations indicated destruction of B-cells in the STZ-treated animals and its prevention by PBN co-treatment. EPR spin trapping experiments in the pancreas indicated the in vivo formation of NO in STZ-treated animals and its attenuation by PBN treatment.
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