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Topic:Molecular Weight

Molecular weight refers to the mass of a molecule, typically expressed in unified atomic mass units (u or Da). In equine research, molecular weight is an important parameter in the study of various biological molecules, including proteins, enzymes, and nucleic acids. Understanding the molecular weight of these molecules aids in characterizing their structure, function, and interactions within the horse's body. It is particularly relevant in pharmacokinetics, where the molecular weight of drugs influences their absorption, distribution, metabolism, and excretion. This section compiles peer-reviewed research studies and scholarly articles that explore the applications and implications of molecular weight in equine science, including its role in drug development, disease diagnostics, and the study of metabolic processes.
Recombinant Salmonella enterica OmpX protein expression and its potential for serologically diagnosing Salmonella abortion in mares.
Veterinary world    September 13, 2023   Volume 16, Issue 9 1790-1795 doi: 10.14202/vetworld.2023.1790-1795
Borovikov S, Ryskeldina A, Tursunov K, Syzdykova A, Akibekov O. abortion in mares is caused by subspecies serovar infection and is characterized by premature (abortion) or non-viable fetus birth. Although all horses are susceptible to infection, the condition is more often clinically manifested in pregnant mares, with most abortions recorded in young females. In addition, nonspecific clinical disease signs and poorly sensitive and effective bacteriological diagnostic methods hinder rapid and reliable infection diagnoses. Immunochemical methods such as enzyme-linked immunosorbent assay (ELISA) and immunochromatography assays can facilitate effective and...
Protein profile of Brazilian Pythium insidiosum isolates.
Medical mycology    February 9, 2018   Volume 56, Issue 4 485-492 doi: 10.1093/mmy/myx071
Dal Ben V, Oliveira RS, Borchardt JL, Valente JSS, Brasil CL, Zambrano CG, Leite FPL, Botton SA, Pereira DIB.Pythium insidiosum is an important aquatic Oomycota that causes pythiosis in mammals, especially horses, dogs, and humans; these inhabit marshy environments in tropical and subtropical areas. The aim of this study was to determine the protein profile, as well as identify likely immunodominant proteins, of Brazilian P. insidiosum isolates from southern Brazil, an important equine pythiosis endemic area. P. insidiosum isolates (horses, n = 20 and dogs, n = 02) were analyzed by SDS-PAGE and Western blot techniques. Horse, cattle, dog, and rabbit sera of both diseased and healthy animals were used...
Alpha-mannosidase activity in stallion epididymal fluid and spermatozoa.
Theriogenology    May 11, 2012   Volume 78, Issue 2 252-262 doi: 10.1016/j.theriogenology.2012.02.033
Retamal CA, Dias AJ, Brasil FC, Lanzana FR, López ML.The expression of α-D-mannosidase activity was fluorometrically and electrophoretically assessed in spermatozoa, epididymal fluid and homogenates of stallion epididymal tissue. Enzyme activity had regional differences; it was higher (P<0.05) in samples from the cauda epididymal region than in samples from the proximal caput region (largely composed of efferent ducts). Based on enzyme activity, as a function of pH of the assay substrate, electrophoretic analysis in native and native/SDS-PAGE conditions, and the effect of inhibitors or activators, we inferred the presence of at least two cat...
Characterization of immunogenic proteins of Trypanosoma evansi isolated from three different Indian hosts using hyperimmune sera and immune sera.
Research in veterinary science    March 26, 2008   Volume 85, Issue 3 534-539 doi: 10.1016/j.rvsc.2008.02.011
Laha R, Sasmal NK.The western blot analysis for identification of immunogenic proteins in whole cell lysate (WCL) antigens (Ags) prepared from the Trypanosoma evansi of buffalo, horse and cattle origins using hyperimmune sera (HIS) showed 11 immunogenic proteins and naturally T. evansi infected immune sera (IS) of horse detected 19 immunogenic proteins. HIS and IS of horse recognized five common immunogenic proteins of relative molecular weight (M(r)) ranges 61-64, 44-47, 33-34, 25-26 and 14-16 kilo Dalton (kDa). HIS rose against WCL Ags of T. evansi of buffalo origin and immune sera of horse cross reacted with...
Biological activities of recombinant equine luteinizing hormone/chorionic gonadotropin (eLH/CG) expressed in Sf9 and Mimic insect cell lines.
Journal of molecular endocrinology    February 5, 2005   Volume 34, Issue 1 47-60 doi: 10.1677/jme.1.01624
Legardinier S, Duonor-Cérutti M, Devauchelle G, Combarnous Y, Cahoreau C.Equine luteinizing hormone (eLH) and chorionic gonadotropin (eCG) are composed of identical alpha and beta polypeptide chains, but eCG subunits are much more heavily glycosylated and sialylated. Consequently, eCG exhibits a much longer half-life than eLH in blood. Recombinant eLH/CG, expressed in Sf9 and Mimic insect cells, were compared with one another and to the natural hormones eCG and eLH. Mimic cells are stably-transformed Sf9 cells, expressing five mammalian genes encoding glycosyltransferases involved in the synthesis of complex N-carbohydrate chains. Recombinant eLH/CG expressed in Mi...
Molecular characterization and expression of equine testicular cytochrome P450 aromatase.
Biochimica et biophysica acta    February 20, 2003   Volume 1625, Issue 3 229-238 doi: 10.1016/s0167-4781(02)00621-8
Seralini GE, Tomilin A, Auvray P, Nativelle-Serpentini C, Sourdaine P, Moslemi S.We characterized testicular equine aromatase and its expression. A 2707 bp cDNA was isolated, it encoded a polypeptide of 503 residues with a deduced molecular mass of 57.8 kDa. The sequence features were those of a cytochrome P450 aromatase, with a 78% polypeptide identity with the human counterpart. The gene has a minimal length of 74 kb comprising at least 9 exons and expresses a 2.8 kb mRNA in the testis. Transient cDNA transfections in E293 cells and in vitro translations in a reticulocyte lysate system allowed aromatase protein and activity detections. The activity increased with androst...
Production and characterisation of two monoclonal antibodies recognising equine IgG Fc receptors.
Veterinary immunology and immunopathology    March 4, 2000   Volume 73, Issue 1 63-71 doi: 10.1016/s0165-2427(99)00153-1
Aggarwal N, Holmes MA.Despite the importance of IgG Fc receptors in the regulation of various immunological mechanisms, these receptors have not been well characterised in the domesticated animals including equines. This paper describes the production of two monoclonal antibodies (CVS 59 and CVS 61) that recognise equine IgG Fc receptors. Fusions were conducted using BALB/c mice hyperimmunised with equine peripheral blood mononuclear cells. Hybridoma supernatants were screened on the basis of their ability to inhibit the rosetting of equine antibody coated sheep erythrocytes with equine peripheral blood mononuclear...
A 105- to 94-kilodalton protein in the epididymal fluids of domestic mammals is angiotensin I-converting enzyme (ACE); evidence that sperm are the source of this ACE.
Biology of reproduction    March 20, 1999   Volume 60, Issue 4 937-945 doi: 10.1095/biolreprod60.4.937
Gatti JL, Druart X, Guérin Y, Dacheux F, Dacheux JL.SDS-PAGE analysis of luminal fluid from the ram testis and epididymis revealed a protein of about 105 kDa in the fluid in the caput epididymal region. The molecular mass of this fluid protein shifted from 105 kDa to 94 kDa in the distal caput epididymidis and remained at 94 kDa in the lower regions of the epididymis. The possible sperm origin of this protein was suggested by the decrease in intensity of a 105-kDa compound on the sperm plasma membrane extract and by its total disappearance from the fluid of animals with impaired sperm production caused by scrotal heating. The 94-kDa protein was...
Role of oligosaccharides in the pharmacokinetics of tissue-derived and genetically engineered cholinesterases.
Molecular pharmacology    January 28, 1998   Volume 53, Issue 1 112-122 doi: 10.1124/mol.53.1.112
Saxena A, Ashani Y, Raveh L, Stevenson D, Patel T, Doctor BP.To understand the role of glycosylation in the circulation of cholinesterases, we compared the mean residence time of five tissue-derived and two recombinant cholinesterases (injected intravenously in mice) with their oligosaccharide profiles. Monosaccharide composition analysis revealed differences in the total carbohydrate, galactose, and sialic acid contents. The molar ratio of sialic acid to galactose residues on tetrameric human serum butyrylcholinesterase, recombinant human butyrylcholinesterase, and recombinant mouse acetylcholinesterase was found to be approximately 1.0. For Torpedo ca...
Antigenic analysis of Rhodococcus equi preparations using different horse sera.
Veterinary microbiology    June 16, 1997   Volume 56, Issue 3-4 247-255 doi: 10.1016/s0378-1135(97)00093-x
Fontanals AM, Becú T, Polledo G, Gaskin CK, Braun M.An R. equi vaccine, prepared under conditions which induce the expression of many antigens, and which has given encouraging results in field trials, was analyzed by SDS-PAGE and immunoblots and compared with other R. equi preparations: a preparation made in with the same technique from a nonvirulent isolate (virulence associated protein negative, VapA-negative); a whole cell preparation of a VapA-positive R. equi, prepared as a standard bacterin; and a semipurified VapA preparation (APTX). The antigens in these preparations were analyzed using hyperimmune sera (from adult horses vaccinated wit...
Further characterization of IgE-binding antigens in horse dander, with particular emphasis on glycoprotein allergens.
Allergy    September 1, 1996   Volume 51, Issue 9 608-613 doi: 10.1111/j.1398-9995.1996.tb04680.x
Johnsen , Thanh DB, Ly Q, Smestad Paulsen B, Wold JK.IgE-binding components in an extract of horse dander were analyzed, especially with regard to the glycoprotein allergens. After SDS-PAGE under reducing conditions and blotting, several of the glycoprotein IgE-binding components, including two distinct bands of 27 and 31 kDa, were detected. Together with several other bands, they were shown to bind to the lectins Sambucus nigra agglutinin (SNA) and Datura stramonium agglutinin (DSA), indicating terminal sialic acid linked alpha 2 --> 6 to galactose, and galactose linked beta 1 --> 4 to N-acetylglucosamine, respectively. Carbohydrate analy...
Evidence that the agent of equine grass sickness may reach neurons by retrograde axonal transport.
The Veterinary record    November 26, 1994   Volume 135, Issue 22 520-523 doi: 10.1136/vr.135.22.520
Griffiths IR, Smith S, Doxey DL, Whitwell K, Love S.Sera from acute and chronic cases of natural grass sickness or normal horses were injected into the parotid salivary gland of ponies. This gland receives its sympathetic innervation from the ipsilateral cranial cervical ganglion. None of the ponies showed any local or systemic signs of illness. After one week the cranial cervical ganglia, stellate and coeliaco-mesenteric ganglia were removed for histological study. Pathological changes were found only in the cranial cervical ganglion ipsilateral to a parotid salivary gland which had received an injection of grass sickness serum. Four out of fi...
Comparison of IgE-binding antigens in horse dander and a mixture of horse hair and skin scrapings.
Allergy    October 1, 1993   Volume 48, Issue 7 535-541 doi: 10.1111/j.1398-9995.1993.tb01111.x
Fjeldsgaard BE, Paulsen BS.Extracts of horse dander (HD) and horse hair and skin scrapings (HHSS) have been compared with respect to their content of proteins and carbohydrates. The protein content of HD is more than double that of HHSS, while the carbohydrate content is of the same order. SDS-PAGE and IEF, both combined with immunoblotting, and CIE/CRIE showed the IgE-binding ability of the proteins/glycoproteins present in the two extracts. SDS-PAGE/immunoblotting showed the presence of mainly the same IgE-binding bands in the two extracts. Nine were detected in HD, and seven in HHSS. Four of these were glycoproteins....
Isolation and characterization of four basic proteins from horse eosinophilic granules.
Biochemical and biophysical research communications    April 30, 1993   Volume 192, Issue 2 373-380 doi: 10.1006/bbrc.1993.1425
Piller K, Portmann P.Four new basic proteins were isolated from horse eosinophils and purified. The eosinophils release these proteins after permeabilization with saponin and degranulation stimulized by guanosine 5'-O-thiotriphosphate. The proteins were separated and purified on a Superose P12- and a Mono S-column by fast protein liquid chromatography. The amino acid composition, the relative molecular mass, the isoelectric point and the partial N-terminal sequence of the four proteins were determined. Papain-activation and ribonuclease activity of the four proteins were tested for comparison with the human eosino...
Immunoblot analysis of the humoral immune response to Pythium insidiosum in horses with pythiosis.
Journal of clinical microbiology    November 1, 1992   Volume 30, Issue 11 2980-2983 doi: 10.1128/jcm.30.11.2980-2983.1992
Mendoza L, Nicholson V, Prescott JF.Reactions to Pythium insidiosum by sera from horses with active pythiosis were investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. Five strains of P. insidiosum were grown in nutrient broth and then sonicated. After centrifugation, supernatant antigens were separated by SDS-PAGE. An exoantigen of Conidiobolus coronatus was also tested. Bands with molecular weights between 97,000 and 14,000 were identified by Coomassie blue and silver staining. After being transferred to nitrocellulose, the antigens were reacted against sera from six horses w...
Purification and kinetic characterization of equine infectious anemia virus reverse transcriptase.
Biochemical and biophysical research communications    November 14, 1991   Volume 180, Issue 3 1365-1371 doi: 10.1016/s0006-291x(05)81346-4
Thomas DA, Furman PA.The reverse transcriptase of Equine Infectious Anemia Virus (EIAV) was partially purified from virus particles and appeared to be a heterodimer with subunit molecular masses of 70 kdal and 59 kdal. The polymerase activity of this enzyme had an absolute requirement for a divalent cation, preferring Mg++ over Mn++. Addition of a monovalent cation to the reaction mixture enhanced, but was not required for enzyme activity. Kinetically, the reverse transcriptase of EIAV is similar to the reverse transcriptase of Human Imunodeficiency Virus Type 1 (HIV-1). Both enzymes have similar Km values for 2'-...
Studies of antigenic components in acid extracts of group C streptococci with special reference to Streptococcus equi.
Zentralblatt fur Bakteriologie : international journal of medical microbiology    September 1, 1990   Volume 273, Issue 4 459-470 doi: 10.1016/s0934-8840(11)80453-6
Groschup M, Müller HP, Weiss R, Schliesser T.For the determination of a species-specific antigen of Streptococcus (S.) equi, acid extracts of group C streptococcal strains from horses (S. equi, S. zooepidemicus, S. equisimilis) were investigated using polyacrylamide gel electrophoresis and the immunoblotting technique. Using sera of horses suffering from strangles as well as sera from horses with respiratory infection of unknown etiology, Western blotting yielded more or less multiple banding reactions with bands in the 70, 54, 42, 40, and 31-28 kd molecular weight ranges against extracts of all of the 3 different bacterial species. Howe...
Isolation, characterization, and quantitative analysis of C-reactive protein from horses.
American journal of veterinary research    August 1, 1990   Volume 51, Issue 8 1215-1220 
Takiguchi M, Fujinaga T, Naiki M, Mizuno S, Otomo K.C-reactive protein (CRP) was isolated from equine serum by use of calcium-dependent affinity chromatography conjugated pneumococcal C-polysaccharide, anion exchange chromatography, and gel filtration. It was identified as genuine CRP by its immunochemical cross-reactivity with anti-human CRP, its homology with human CRP in amino acid composition, and its pentameric structure as revealed by electron microscopy. Purified equine CRP had a molecular weight of approximately 118,000 and was composed of 5 identical, nonglycosylated and noncovalently associated subunits with molecular weight of approx...
Primary structure of horse serotransferrin glycans. Demonstration that heterogeneity is related to the number of glycans and to the presence of N-acetylneuraminic acid and N-acetyl-4-O-acetylneuraminic acid.
European journal of biochemistry    December 22, 1989   Volume 186, Issue 3 583-590 doi: 10.1111/j.1432-1033.1989.tb15248.x
Coddeville B, Stratil A, Wieruszeski JM, Strecker G, Montreuil J, Spik G.Three serotransferrin variants Tf 2a, Tf 4b and Tf 5b were isolated in an homogeneous form from a preparation of homozygous horse serotransferrin Tf 0. On the basis of the results concerning molecular mass determination and the carbohydrate analysis, it is concluded that the serotransferrin variant Tf 2a contains only one glycan while variants Tf 4b and Tf 5b contain two glycans. The structure of all of the glycans has been established by combining methylation analysis, mass spectrometry and 400-MHz 1H-NMR spectroscopy. From the obtained results, it appears that the two glycans of Tf 5b varian...
A growth-promoting factor for human myeloid leukemia cells from horse serum identified as horse serum transferrin.
Biochimica et biophysica acta    January 17, 1989   Volume 1010, Issue 1 28-34 doi: 10.1016/0167-4889(89)90180-8
Yoshinari K, Yuasa K, Iga F, Mimura A.A growth-promoting factor for human myeloid cells was purified to apparent homogeneity from horse serum by a combination of gel filtration, blue Sepharose affinity chromatography, Mono Q anion-exchange chromatography, Mono P chromatofocusing and sodium dodecyl sulfate polyacrylamide gel electrophoresis. The growth promoter was an iron-bound, single glycopolypeptide chain with a molecular weight of 84,000, an isoelectric point of 5.4 and an amino terminal sequence of Glu-Gln-Thr-Val-Arg-Trp-Cys-Thr-Val-Ser-Asn-His-Glu-Val-Ser-Lys-. According to the results of the amino acid sequence, iron bindi...
Comparative immunochemical studies of carbonic anhydrase III in horses and other mammalian species.
Comparative biochemistry and physiology. B, Comparative biochemistry    January 1, 1988   Volume 91, Issue 1 91-96 doi: 10.1016/0305-0491(88)90118-6
Nishita T, Matsushita H.1. Carbonic anhydrase III (CA-III) from different mammalian species (horse, cow, dog, cat, rat and rabbit) has been analyzed by the immunodiffusion technique with anti-equine CA-III serum. 2. Immunodiffusion demonstrated the absence of cross-reactivity between isozyme CA-I, CA-II, and CA-III. 3. Cross-reactions were observed between the CA-III from all the species examined except the rabbit. 4. Molecular weights and isoelectric points of CA-III from different species were determined by Western blotting.
Comparison of the serum amylases of farm animals.
Comparative biochemistry and physiology. B, Comparative biochemistry    January 1, 1987   Volume 88, Issue 3 963-968 doi: 10.1016/0305-0491(87)90271-9
Archibald AL.1. Serum isoamylases with alpha-glucosidase activity from cattle, sheep, horses, goats, red deer, pigs and dogs were compared to one another. 2. The isoamylases from cattle and pigs were polymorphic. 3. In agarose gel electrophoresis the isoamylases behaved as alpha-1-globulins but in starch gel electrophoresis they were differentially retarded by affinity effects. 4. Molecular weights were estimated: cattle (417,000); sheep (402,000); horses (420,000); goat (399,000); red deer (405,000); pigs (375,000) and dogs (390,000). 5. Isoelectric points were estimated: cattle, sheep, goat and red deer ...
Lysosomal arylsulfatases A and B from horse blood leukocytes: purification and physico-chemical properties.
Biology of the cell    January 1, 1986   Volume 57, Issue 2 147-152 doi: 10.1111/j.1768-322x.1986.tb00471.x
Wojczyk B.Lysosomal arylsulfatases A and B (aryl-sulfate sulfohydrolases, EC 3.1.6.1) from horse leukocytes were purified about 680-fold and 70-fold, respectively, starting from a crude extract of the azurophil and specific granules of leukocytes, by affinity, ion exchange, and gel filtration chromatography. Purified arylsulfatase A displayed anomalous kinetics, a pH optimum at 5.2, an isoelectric point at 4.3, and a Km value for p-nitrocatechol sulfate (pNCS) of 0.37 mM. This enzyme was found to exist in two association states depending on pH: a high molecular weight form at pH 5.0 and a low molecular ...
Characteristics of an R antigen common to Streptococcus equi and zooepidemicus.
The Cornell veterinarian    January 1, 1986   Volume 76, Issue 1 49-60 
Timoney JF.An R antigen of the group C streptococcus S. equi that cross reacts with a similar antigen of S. zooepidemicus has been identified and characterized. It is acid, heat and trypsin resistant, but pepsin sensitive and has an isoelectric point of 4.8. The amino acids in highest concentration are glutamic, aspartic, alanine, leucine, and valine. Bacterial components released in a French Press contain large amounts of R antigen, which is present also in culture supernatants and acid extracts. It has a molecular weight of about 82,000. Trypsin extraction of cells yields molecules of predominantly 56,...
Unusual compound of small molecular weight in the serum of horses with acute grass sickness.
Research in veterinary science    May 1, 1985   Volume 38, Issue 3 329-333 
Johnson P.An unusual compound of small molecular weight has been detected in serum from horses with acute grass sickness by solvent extractions and thin-layer chromatography. The substance has not been detected in the serum of normal horses or cases of equine colic and apparently disappears from grass sickness serum after two to three days of clinical illness. Although this compound is found in sera which are known to possess in vivo neurotoxicity, this property could not be demonstrated in either the total chloroform extract which contains the compound or in the hydrophilic serum components remaining a...
Immunologically reactive proteins of Streptococcus equi.
Infection and immunity    April 1, 1985   Volume 48, Issue 1 29-34 doi: 10.1128/iai.48.1.29-34.1985
Timoney JF, Trachman J.Immunologically reactive proteins in acid extracts and culture supernatants of Streptococcus equi were recognized through a combination of chromatographic and immunologic procedures. Both high- and low-molecular-weight components of each of these protein preparations were protective for mice and were, therefore, presumed to contain a variety of hydrolytic products or fragments of the M protein of S. equi. Convalescent horse sera that exhibited strong bactericidal activity for S. equi always reacted with polypeptides in the molecular weight range of 24,000 to 29,000, whereas preinfection sera d...
Mucosal nasopharyngeal immune responses of horses to protein antigens of Streptococcus equi.
Infection and immunity    March 1, 1985   Volume 47, Issue 3 623-628 doi: 10.1128/iai.47.3.623-628.1985
Galan JE, Timoney JF.Mucosal nasopharyngeal immunoglobulin A (IgA) and IgG responses to proteins of Streptococcus equi were studied in horses after the experimental production of strangles. S. equi-specific IgA and IgG titers in nasopharyngeal mucus were much higher in samples from animals 1 to 2 weeks after challenge than in samples from control animals. Although IgA was the major immunoglobulin in nasal mucus, there was more antibody activity associated with IgG as measured by radioimmunoassay. Great differences between the specificities of antibodies in nasal mucus and in serum were detected. IgA and IgG of muc...
Physico-chemical properties of pregnant mare serum gonadotropin.
Biochimica et biophysica acta    February 27, 1981   Volume 667, Issue 2 267-276 doi: 10.1016/0005-2795(81)90192-6
Combarnous Y, Salesse R, Garnier J.Pregnant mare serum gonadotropin exhibits a dissociation at acid pH as shown by the drop of s20,w values from 3.52 S at pH 8.1 to 2.52 S at pH 2.0. The dissociation is accompanied by an absorbance change with a maximum at 287 nm and a parallel loss of both follicle-stimulating hormone (FSH) and luteinizing hormone (LH) activities as followed by radioreceptor assays. The apparent pKa of the acid transition is 3.45 with an extremely slow and temperature-dependent rate at pH 2.0 (1.8 . 10(-4) s-1 at 37 degrees C). By gel filtration the molecular weight of the active hormone is estimated to be 45 ...
The lectin-binding sites of the erythrocyte membrane components of horse, swine and sheep. Characterization by their molecular weights.
Hoppe-Seyler's Zeitschrift fur physiologische Chemie    March 1, 1979   Volume 360, Issue 3 421-428 doi: 10.1515/bchm2.1979.360.1.421
Gürtler LG, Yeboa DA, Cleve H.The membrane components of equine, porcine and ovine erythrocytes were separated by sodium dodecylsulfate polyacrylamide gel electrophoresis and subsequently incubated with the radioiodinated lectins from lentils (LCH), castorbeans (RCA), Phaseolus beans (L-PHA), gorse seeds (UEH-F) and from vineyard snails (HPA). The following individual glycoproteins could be labeled: gp 26, 33, 100 and 320 in horse erythrocytes, gp 24, 46, 75, 130 and 210 in swine and gp 24, 57, 100 and 210 in sheep erythrocytes.
Experimental studies of neurotoxic activity in blood fractions from acute cases of grass sickness.
Research in veterinary science    January 1, 1977   Volume 22, Issue 1 1-4 
Gilmour JS, Mould DL.Plasma, serum and cells were prepared from blood taken from acute cases of grass sickness, and plasma was fractionated by gel filtration and salt precipatation. These preparations were all tested for neurotoxic activity by injection into ponies. Plasma and serum were found to produce the neurohistological changes seen in grass sickness, as was a plasma protein fraction of molecular weight 30,000 or greater. Activity was retained following storage at--75 degrees C for 15 months. Plasma given orally to a pony produced no detectable effect, nor was activity demonstrated following the injection of...