Analyze Diet

Topic:Laboratory Methods

Laboratory methods in equine research encompass a variety of techniques and procedures used to analyze biological samples from horses to study health, disease, genetics, and physiology. These methods include hematological analyses, biochemical assays, molecular biology techniques, and microbiological cultures. Commonly utilized laboratory techniques involve blood tests for complete blood count (CBC) and serum chemistry, polymerase chain reaction (PCR) for genetic and infectious disease studies, and enzyme-linked immunosorbent assays (ELISA) for detecting specific proteins or antibodies. These methods provide valuable data that contribute to understanding equine health and disease mechanisms. This page compiles peer-reviewed research studies and scholarly articles that explore the application, development, and outcomes of laboratory methods in the context of equine research.
Inhibition of in vitro maturation of equine oocytes by interleukin 1 beta via specific IL-1 receptors.
Reproduction (Cambridge, England)    October 4, 2003   Volume 126, Issue 4 509-515 doi: 10.1530/rep.0.1260509
Martoriati A, Caillaud M, Goudet G, Gérard N.Interleukin 1 beta (IL-1 beta) inhibits the LH-induced resumption of meiosis of equine oocytes in vitro. The present study was performed to clarify this inhibitory effect of IL-1 beta by testing increasing concentrations of IL-1 beta, and by measuring the effect of addition of IL-1 receptor antagonist (IL-1RA) to the culture medium. The effect of IL-1 beta on epidermal growth factor (EGF)-induced resumption of meiosis was also studied. Cumulus-oocyte complexes (COCs) were collected from subordinate follicles on ovaries obtained from an abattoir. In five distinct experiments, COCs were cultured...
Development and testing of a modular strain measurement clip.
Journal of biomechanics    October 3, 2003   Volume 36, Issue 11 1669-1674 doi: 10.1016/s0021-9290(03)00173-8
Whan G, Phillips J, Bullock S, Runciman RJ, Pearce S, Hurtig M.A novel, multi-use, low-stiffness and low-cost transducer for measuring in vitro strains has been developed and tested. Currently available strain measurement methods are either too expensive, too complicated or too inflexible for multi-use strain measurement. The stainless-steel modular strain measurement clip introduced here was instrumented with four 350 Omega axial strain gauges in a full Wheatstone bridge configuration to take advantage of commonly available strain gauge amplifier equipment. Adjustable extension arms were designed to allow greater application versatility. The clip was cal...
Equine cyathostome populations: accuracy of species composition estimations.
Veterinary parasitology    October 2, 2003   Volume 116, Issue 1 15-21 doi: 10.1016/s0304-4017(03)00239-5
Chapman MR, Kearney MT, Klei TR.Historically, surveys of equine parasites either are not quantitative in regard to prevalence and intensities of cyathostome species, or if quantitative, are estimates based on the identification of a very small sample of the population. Commonly 100-200 worms are identified. In the current study cyathostomes from 10 ponies were counted and identified to species in subsets of approximately 200 worms each from 5% aliquots of the large intestine contents until all worms in the aliquot were examined. A mean of 10.9+/-4.3 species were identified by examining 200 cyathostomes from each animal. This...
Large-volume injection gas chromatography-mass spectrometry for automated broad-spectrum drug screening in horse urine.
Journal of analytical toxicology    October 1, 2003   Volume 27, Issue 6 325-331 doi: 10.1093/jat/27.6.325
Stanley SD, McKemie D, Skinner W.A rapid, sensitive, and rugged method for detecting drugs and drug metabolites in extracts of horse urine is described. The use of large-volume injection (LVI) gas chromatography-mass spectrometry (GC-MS) for analysis of horse urine extracts allowed automation of the derivatization procedure and reduction of the sample volume from 5 mL to 1 mL of urine. An autosampler and temperature-programmable inlet were used to automatically dissolve the sample extract and form trimethylsilyl derivatives of over 200 analytes. The suitability of this procedure for routine GC-MS detection of approximately 80...
Reactive oxygen species promote tyrosine phosphorylation and capacitation in equine spermatozoa.
Theriogenology    September 27, 2003   Volume 60, Issue 7 1239-1247 doi: 10.1016/s0093-691x(03)00144-4
Baumber J, Sabeur K, Vo A, Ball BA.The objective of this study was to examine the influence of reactive oxygen species (ROS) on equine sperm capacitation. Motile equine spermatozoa were separated on a discontinuous Percoll gradient, resuspended at 10 x 10(6)ml in Tyrode's medium supplemented with BSA (0.5%) and polyvinyl alcohol (0.5%) and incubated at 39 degrees C for 2h with or without the xanthine (X; 0.1mM)-xanthine oxidase (XO; 0.01 U/ml) system or NADPH (0.25 mM). The importance of hydrogen peroxide or superoxide for capacitation was determined by the addition of catalase (CAT; 150 U/ml) or superoxide dismutase (SOD; 150 ...
Serum beta-carotene and alpha-tocopherol in horses fed beta-carotene via grass-meal or a synthetic beadlet preparation with and without added dietary fat.
Journal of animal physiology and animal nutrition    September 27, 2003   Volume 87, Issue 3-4 174-180 doi: 10.1046/j.1439-0396.2003.00430.x
Kienzle E, Kaden C, Hoppe PP, Opitz B.The serum response of beta-carotene as an indicator of bioavailability was compared after feeding beta-carotene (0.8 mg/kg body weight) either from grass meal or a synthetic beadlet preparation (Lucarotin). Both were each given without or with added dietary vegetable fat (2-2.5% vs. 6.6% fat in dry matter) in a Latin square design with four horses. The nutritionally complete diet was supplemented with alpha-tocopherol (4 mg/kg body weight). Each treatment period (4 weeks, two serum samples) was followed by a washout period of 4 weeks with low intakes of beta-carotene (traces) and alpha-tocophe...
Development of competitive ELISA for serodiagnosis on African horsesickness virus using baculovirus expressed VP7 and monoclonal antibody.
Journal of virological methods    September 23, 2003   Volume 113, Issue 1 13-18 doi: 10.1016/s0166-0934(03)00217-9
Kweon CH, Kwon BJ, Ko YJ, Kenichi S.VP7, the sero-group common antigen, of African horsesickness virus (AHSV-4) was expressed in insect cells by recombinant baculovirus. To develop a specific diagnostic method, monoclonal antibody (Mab) against VP7 was prepared and investigated as diagnostic reagent with the baculovirus expressed VP7. However, the Mab against VP7 of AHSV cross-reacted with Chuzan virus by the indirect immunofluorescence assay (IFA), confirming the presence of conserved domain of VP7 among Orbiviruses. This study describes two types of ELISA; Mab linked indirect (I-ELISA) and competitive-ELISA (C-ELISA) using bac...
Detection of equine arteritis virus (EAV)-specific cytotoxic CD8+ T lymphocyte precursors from EAV-infected ponies.
The Journal of general virology    September 19, 2003   Volume 84, Issue Pt 10 2745-2753 doi: 10.1099/vir.0.19144-0
Castillo-Olivares J, Tearle JP, Montesso F, Westcott D, Kydd JH, Davis-Poynter NJ, Hannant D.Equine arteritis virus (EAV) causes a systemic infection in equids with variable outcome, ranging from subclinical infections to severe disease, and also has the capacity to induce abortion in pregnant mares and persistent infections in stallions. The serum virus-neutralizing antibody response that invariably develops in the infected animal lasts for many months or years and is believed to play an important role in virus clearance. However, very little is known about cellular immunity against EAV because of a lack of methods for evaluating these immune responses. In the present study, we descr...
Cyclooctadepsipeptides–an anthelmintically active class of compounds exhibiting a novel mode of action.
International journal of antimicrobial agents    September 19, 2003   Volume 22, Issue 3 318-331 doi: 10.1016/s0924-8579(03)00219-x
Harder A, Schmitt-Wrede HP, Krücken J, Marinovski P, Wunderlich F, Willson J, Amliwala K, Holden-Dye L, Walker R.There are three major classes of anthelmintics for veterinary use: the benzimidazoles/prebenzimidazoles, the tetrahydropyrimidines/imidazothiazoles, and the macrocyclic lactones. In nematodes, there are five targets for the existing anthelmintics: the nicotinergic acetylcholine receptor which is the target of tetrahydropyrimidines/imidazothiazoles and indirectly that of the acetylcholineesterase inhibitors; the GABA receptor which is the target of piperazine, the glutamate-gated chloride channel as the target of the macrocyclic lactones, and beta-tubulin as the target of prebenzimidazoles/benz...
Endocrine responses in mares and geldings with high body condition scores grouped by high vs. low resting leptin concentrations.
Journal of animal science    September 13, 2003   Volume 81, Issue 9 2311-2321 doi: 10.2527/2003.8192311x
Cartmill JA, Thompson DL, Storer WA, Gentry LR, Huff NK.Previous observations from this laboratory indicated that horses with high BCS could have resting plasma leptin concentrations ranging from low (1 to 5 ng/mL) to very high (10 to 50 ng/mL). To study the possible interactions of leptin secretion with other endocrine systems, BCS and plasma leptin concentrations were measured on 36 mares and 18 geldings. From mares and geldings that had a mean BCS of at least 7.5, five with the lowest (low leptin) and five with the highest (high leptin) leptin concentrations were selected. Jugular blood samples were collected twice daily for 3 d from the 20 sele...
Pharmacological and biochemical characterization of the beta-adrenergic signal transduction pathway in different segments of the respiratory tract.
Biochemical pharmacology    September 10, 2003   Volume 66, Issue 6 1067-1081 doi: 10.1016/s0006-2952(03)00460-x
Abraham G, Kottke C, Dhein S, Ungemach FR.Although in the respiratory system there is great therapeutic interest in manipulating and understanding the beta-adrenoceptor-G-protein-adenylate cyclase (AC) signal transduction pathway, little is known on segmental differences among lung, bronchus, and trachea with regard to the receptor concentration and interaction to G-proteins and coupling to AC. In this study, patterns of distribution and absolute quantities of beta-adrenoceptor subtypes beta(1) and beta(2) were determined in membranes of equine lung parenchyma, bronchial and tracheal epithelium with the underlying smooth muscle by sat...
[Fluorescence spectroscopic study of interaction between Fe-protoporphyrin in myoglobin and Cu(II) ions].
Guang pu xue yu guang pu fen xi = Guang pu    September 5, 2003   Volume 23, Issue 3 532-534 
Feng YY, Yang H, Gu XT, Jiang HJ, Lu TH.In this paper, the interaction between Cu(II) ions and Fe-protoporphyrin in horse-heart myoglobin (FePP-Mb) was studied. As a result, some of the Fe(II) ions in FePP-Mb were found to be replaced by Cu(II) ions forming CuPP-Mb, by adding Cu(II) ions into the myoglobin solution. The interaction became stronger when adding more Cu(II) ions into the myoglobin solution. By studying the metal ions' interaction with myoglobin proteins as macromolecules and discussing the interaction mechanism, this work provides a theoretical basis for the further study of hazardous metal ions' interaction with the h...
Quantitative analysis of eumelanin and pheomelanin in humans, mice, and other animals: a comparative review.
Pigment cell research    September 3, 2003   Volume 16, Issue 5 523-531 doi: 10.1034/j.1600-0749.2003.00072.x
Ito S, Wakamatsu K.The color of hair, skin, and eyes in animals mainly depends on the quantity, quality, and distribution of the pigment melanin, which occurs in two types: black to brown eumelanin and yellow to reddish pheomelanin. Microanalytical methods to quantify the amounts of eumelanin and pheomelanin in biological materials were developed in 1985. The methods are based on the chemical degradation of eumelanin to pyrrole-2,3,5-tricarboxylic acid and of pheomelanin to aminohydroxyphenylalanine isomers, which can be analyzed and quantitated by high performance liquid chromatography. This review summarizes a...
Effects of growth factors (EGF, PDGF-BB and TGF-beta 1) on cultured equine epithelial cells and keratocytes: implications for wound healing.
Veterinary ophthalmology    September 3, 2003   Volume 6, Issue 3 211-217 doi: 10.1046/j.1463-5224.2003.00296.x
Haber M, Cao Z, Panjwani N, Bedenice D, Li WW, Provost PJ.The physiologic mechanisms involving growth factors, including PDGF-BB, EGF, and TGF-beta 1, as potent mediators of fibroblasts and epithelial cells in corneal wound healing remain unknown. The goal of this study was to determine culture methods for equine epithelial cells and keratocytes and to investigate how exogenous growth factors influence proliferation of both cell types. Methods: Cell cultures were established from healthy corneas harvested from horses immediately following euthanasia and maintained using standard tissue culture protocols. To determine the effects of PDGF-BB, EGF, TGF-...
Activation of equine nuclear transfer oocytes: methods and timing of treatment in relation to nuclear remodeling.
Biology of reproduction    September 3, 2003   Volume 70, Issue 1 46-53 doi: 10.1095/biolreprod.103.018200
Choi YH, Love LB, Westhusin ME, Hinrichs K.Early development of embryos produced by transfer of equine nuclei to bovine cytoplasts is superior to that of intraspecies equine nuclear transfer embryos. This may be related to differences in chromatin remodeling or efficiency of activation between the two oocyte types. The pattern of donor nucleus remodeling was examined in equine-equine and equine-bovine reconstructed oocytes. Chromosome condensation occurred in equine cytoplasts by 2 h but was not seen in bovine cytoplasts until 4 h. We investigated the effect of activation of equine-equine reconstructed oocytes at <30 min or at 2 h a...
Assessing the agreement of Western blot test results for paired serum and cerebrospinal fluid samples from horses tested for antibodies to Sarcocystis neuronaf.
Veterinary parasitology    August 26, 2003   Volume 115, Issue 3 233-238 doi: 10.1016/s0304-4017(03)00224-3
Rossano MG, Kaneene JB, Schott HC, Sheline KD, Mansfield LS.Equine protozoal myeloencephalitis (EPM) is a neurological disease of equids that is caused by infection of the central nervous system with Sarcocystis neurona. Veterinarians diagnose EPM by performing a neurological examination and by ordering Western blot tests for antibodies to S. neurona in the blood and/or cerebrospinal fluid (CSF). The negative predictive value of the Western blot test is generally accepted to be high for both serum and CSF. If the agreement between serum and CSF test results is strong, serum tests could be used to substitute for CSF tests in some cases. The purpose of t...
Sensitive liquid chromatographic/tandem mass spectrometric method for the determination of beclomethasone dipropionate and its metabolites in equine plasma and urine.
Journal of mass spectrometry : JMS    August 26, 2003   Volume 38, Issue 8 823-838 doi: 10.1002/jms.495
Guan F, Uboh C, Soma L, Hess A, Luo Y, Tsang DS.Beclomethasone dipropionate (BDP) is a potent pro-drug to beclomethasone (BOH) and is used in the treatment of chronic and acute respiratory disorders in the horse. The therapeutic dose of BDP (325 microg per horse) by inhalation results in very low plasma and urinary concentrations of BDP and its metabolites that pose a challenge to detection and confirmation by equine forensic laboratories. To solve this problem, a method involving the use of a liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS) was developed for the detection, confirmation and quantification of the analyt...
Effect of capacitation of stallion sperm with polyvinylalcohol or bovine serum albumin on penetration of bovine zona-free or partially zona-removed equine oocytes.
Journal of animal science    August 21, 2003   Volume 81, Issue 8 2080-2087 doi: 10.2527/2003.8182080x
Choi YH, Landim-Alvarenga FC, Seidel GE, Squires EL.Experiments were conducted to study effects of macromolecules on stallion sperm capacitation and fertilization as determined by penetration of bovine zona-free and equine partially zona-removed oocytes. Stallion sperm were capacitated in TYH medium (modified Krebs-Ringer bicarbonate) supplemented with either 1 mg/mL of polyvinylalcohol (PVA) or 4 mg/mL of BSA. Capacitation was induced with 8 bromoadenosine cyclic monophosphate (8BrcAMP; 0.5 mM) alone or in combination with 0.1 microM of ionomycin. Intraspecies gametes were co-incubated in TYH/PVA or TYH/BSA for 18 to 20 h. For zona-free bovine...
Immunologic analysis of blood samples obtained from horses and stored for twenty-four hours.
American journal of veterinary research    August 21, 2003   Volume 64, Issue 8 1003-1009 doi: 10.2460/ajvr.2003.64.1003
Witonsky S, Gogal RM, Buechner-Maxwell V, Ahmed SA.To determine whether immune function can be accurately assessed in blood samples obtained from horses and refrigerated overnight and whether a nonradioactive lymphocyte proliferation assay can be used to evaluate samples obtained from horses. Methods: 224 blood samples from 28 clinically normal adult horses. Methods: Heparinized blood samples were collected. Each sample was divided into 2 equal aliquots. One aliquot was refrigerated overnight to simulate overnight shipping of blood samples, and the other aliquot was evaluated on the day of blood collection. Lymphocytes were isolated and enumer...
Equine arteritis virus non-structural protein 1, an essential factor for viral subgenomic mRNA synthesis, interacts with the cellular transcription co-factor p100.
The Journal of general virology    August 15, 2003   Volume 84, Issue Pt 9 2317-2322 doi: 10.1099/vir.0.19297-0
Tijms MA, Snijder EJ.Non-structural protein 1 (nsp1), the N-terminal subunit of the replicase polyprotein of the arterivirus Equine arteritis virus (EAV), is essential for viral subgenomic mRNA synthesis, but fully dispensable for genome replication. However, at the molecular level, the role of nsp1 in EAV subgenomic mRNA synthesis is poorly understood. A yeast two-hybrid screen did not reveal interactions between EAV nsp1 and other viral non-structural proteins or the nucleocapsid protein, although both nsp1 and the nucleocapsid protein were found to form homomers. Subsequently, a yeast two-hybrid screen of a HeL...
Effects of in vitro production on horse embryo morphology, cytoskeletal characteristics, and blastocyst capsule formation.
Biology of reproduction    August 6, 2003   Volume 69, Issue 6 1895-1906 doi: 10.1095/biolreprod.103.018515
Tremoleda JL, Stout TA, Lagutina I, Lazzari G, Bevers MM, Colenbrander B, Galli C.Blastocyst formation rates during horse embryo in vitro production (IVP) are disappointing, and embryos that blastulate in culture fail to produce the characteristic and vital glycoprotein capsule. The aim of this study was to evaluate the impact of IVP on horse embryo development and capsule formation. IVP embryos were produced by intracytoplasmic sperm injection of in vitro matured oocytes and either culture in synthetic oviduct fluid (SOF) or temporary transfer to the oviduct of a ewe. Control embryos were flushed from the uterus of mares 6-9 days after ovulation. Embryo morphology was eval...
Muscarinic receptor subtypes mediate vasorelaxation in isolated horse deep dorsal penile vein.
Urology    August 2, 2003   Volume 62, Issue 2 357-361 doi: 10.1016/s0090-4295(03)00253-x
Martínez AC, Hernández M, Rivera L, Recio P, García-Sacristán A, Benedito S.To investigate the effect of acetylcholine (ACh) on horse deep dorsal penile vein and to characterize the muscarinic receptor subtypes involved in this response. Methods: Vein rings were mounted in an organ bath chamber, and the isometric tension was recorded. Results: In phenylephrine-contracted veins, ACh (1 nM to 1 microM) induced endothelium-dependent relaxation. The muscarinic receptor antagonist, atropine, produced parallel rightward shifts of the ACh response curves (pA2 = 10.04; pK(B) = 9.98). Carbachol (10 nM to 100 microM) also evoked relaxation in the vein segments, but showed a low...
Analysis of ELA-DQB exon 2 polymorphism in Argentine Creole horses by PCR-RFLP and PCR-SSCP.
Journal of veterinary medicine. A, Physiology, pathology, clinical medicine    July 31, 2003   Volume 50, Issue 6 280-285 doi: 10.1046/j.1439-0442.2003.00543.x
Villegas-Castagnasso EE, Díaz S, Giovambattista G, Dulout FN, Peral-García P.The second exon of equine leucocyte antigen (ELA)-DQB genes was amplified from genomic DNA of 32 Argentine Creole horses by PCR. Amplified DNA was analysed by PCR-restriction fragment length polymorphism (RFLP) and PCR-single-strand conformation polymorphism (SSCP). The PCR-RFLP analysis revealed two HaeIII patterns, four RsaI patterns, five MspI patterns and two HinfI patterns. EcoRI showed no variation in the analysed sample. Additional patterns that did not account for known exon 2 DNA sequences were observed, suggesting the existence of novel ELA-DQB alleles. PCR-SSCP analysis exhibited se...
Detection of EHV-1 and EHV-4 in placental sections of naturally occurring EHV-1- and EHV-4-related abortions in the UK: use of the placenta in diagnosis.
Equine veterinary journal    July 24, 2003   Volume 35, Issue 5 430-433 doi: 10.2746/042516403775600451
Gerst S, Borchers K, Gower SM, Smith KC.EHV-1 and EHV-4 abortion diagnosis is based upon detailed examination of the aborted fetus. However, in some cases, only the placenta is available for examination. Furthermore, the contribution of lesions in the placenta to pathogenesis and diagnosis of EHV-1 and EHV-4 abortion has been neglected. Objective: To assess the utility of placental examination in equine herpesvirus-1 (EHV-1) and EHV-4 abortion diagnosis. Methods: Sections of allantochorion from 49 herpesvirus abortions were analysed by PCR, in situ hybridisation and immunostaining. Results: Virus-specific nested PCR confirmed the pr...
Comparison of in vitro methods and faecal egg count reduction test for the detection of benzimidazole resistance in small strongyles of horses.
Veterinary research communications    July 23, 2003   Volume 27, Issue 4 281-288 doi: 10.1023/a:1024079907895
Königová A, Várady M, Corba J.The objective of the study was to compare the in vitro egg hatch test (EHT), larval development test (LDT) and in vivo faecal egg count reduction test (FECR test) for the detection of benzimidazole resistance in equine strongyles. The presence of resistant or susceptible strongyle populations was determined in 25 stud farms using the in vivo FECR test and in vitro EHT. On the basis of the FECR values, resistance to fenbendazole was detected on 15 of the 25 farms (60%). The ED50 value (anthelmintic concentration producing 50% inhibition of hatching) for suspected resistant populations varied fr...
[Expression and immunogenicity of equine infectious anemia virus membrane protein GP90]. Dai CB, Xiao Y, Lu H, Shen RX, Shao YM.Membrane protein GP90 of China equine infectious anemia virus (EIAV) vaccine strain (DLV) and its parental wild type LN strain were expressed with Bac-to-Bac baculovirus expression system and BALB/c mice were inoculated with purified protein, thereby to explore the availability of protein for differential diagnosis and potential for preparing genetically engineered vaccine. Methods: The authors infected donkey PBMC culture with China EIAV vaccine strain (DLV) and its parental wild type LN strain, extracted its proviral DNA as template, amplified the GP90 of DLV and LN, respectively, and expres...
Equine ehrlichiosis in Italy.
Annals of the New York Academy of Sciences    July 16, 2003   Volume 990 259-263 doi: 10.1111/j.1749-6632.2003.tb07374.x
Scarpulla M, Caristo ME, Macri G, Lillini E.The authors review equine granulocytic ehrlichiosis (EGE) in Italy from 1996 to 2002. In 1996, the first case of EGE has been observed in a horse affected with specific symptomatology (fever, lethargy, anorexia, limb edema, thrombocytopenia, and petechiae). In 1997, a seroepidemiological survey was performed in the province of Rome on 563 animals using IFAT. The authors describe the last case, which occurred on 2002 in a 15-year-old male, bay, half-breed, tick-infested horse. Clinical features included fever, lethargy, limb edema, icterus, leukocytopenia, and thrombocytopenia. Laboratory tests...
Assessment of three variations of the 1,9-dimethylmethylene blue assay for measurement of sulfated glycosaminoglycan concentrations in equine synovial fluid.
American journal of veterinary research    July 15, 2003   Volume 64, Issue 7 900-906 doi: 10.2460/ajvr.2003.64.900
Oke SL, Hurtig MB, Keates RA, Wright JR, Lumsden JH.To determine whether 3 variations of the 1,9-dimethylmethylene blue (DMMB) assay yield comparable results when measuring sulfated glycosaminoglycan (sGAG) concentrations in equine synovial fluid (SF). Methods: 25 samples of SF collected from affected joints of 13 horses and 13 samples of SF collected from nonaffected (control) joints of 4 horses. Methods: Sulfated glycosaminoglycan concentrations were measured by the direct spectrophotometric (ie, Farndale), microplate, and indirect DMMB assays in samples of SF collected from normal and affected joints and in samples digested with nucleases, p...
Development of a solid-phase assay for measurement of sulfated glycosaminoglycan concentrations in equine synovial fluid.
American journal of veterinary research    July 15, 2003   Volume 64, Issue 7 894-899 doi: 10.2460/ajvr.2003.64.894
Oke SL, Hurtig MB, Keates RA, Wright JR.To develop a new 1,9-dimethylmethylene blue (DMMB) assay for measurement of sulfated glycosaminoglycan (sGAG) concentrations in equine synovial fluid (SF) by use of membrane technology and to compare the assay's ability to measure sGAG concentrations with that of 2 other established DMMB assays. Methods: 25 samples of SF collected from affected joints of 14 horses and 13 samples of SF collected from nonaffected (control) joints of 4 horses. Methods: A solid-phase DMMB assay was developed to measure sGAG concentrations in SE Results for the assay were then compared with results obtained by use ...
Amyloid protofilaments from the calcium-binding protein equine lysozyme: formation of ring and linear structures depends on pH and metal ion concentration.
Journal of molecular biology    July 10, 2003   Volume 330, Issue 4 879-890 doi: 10.1016/s0022-2836(03)00551-5
Malisauskas M, Zamotin V, Jass J, Noppe W, Dobson CM, Morozova-Roche LA.The calcium-binding equine lysozyme has been found to undergo conversion into amyloid fibrils during incubation in solution at acidic pH. At pH 4.5 and 57 degrees C, where equine lysozyme forms a partially unfolded molten globule state, the protein forms protofilaments with a width of ca. 2 nm. In the absence of Ca(2+) the protofilaments are present as annular structures with a diameter of 40-50 nm. In the presence of 10 mM CaCl(2) the protofilaments of equine lysozyme are straight or curved; they can assemble into thicker threads, but they do not appear to undergo circularisation. At pH 2.0, ...