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Biomedical subjects

L D Olson

Publications and source records attributed to L D Olson.

At least 19 recordsLinked to original sources
PubMed1996

Enhanced isolation of Serpulina hyodysenteriae by using sliced agar media.

A method has been developed for separating Serpulina hyodysenteriae, a large spirochete and the causative agent of swine dysentery (SD), from other fecal anaerobic bacteria in rectal and colonic swabs. This was done by cutting the blood agar in parallel cuts and streaking perpendicular to the cuts in the center of the petri dish. Migration of S. hyodysenteriae from the central streak was apparent by the presence of strong beta-hemolysis along the edges of the cuts. If only S. hyodysenteriae migrated in the cut, they migrated to the end of the cut. However, if both motile bacteria and S. hyodysenteriae migrated in the cut, the motile bacteria migrated to the end of the cut where they formed colonies and the S. hyodysenteriae located along the edges of the cut between the colonies of motile bacteria and the central streak. Although motile bacteria were present where S. hyodysenteriae located, the growth of the motile bacteria was partially inhibited since they rarely formed visible colonies and were low in number. The cut in the agar was thought to improve traction for the serpentine movement of the S. hyodysenteriae and for the flagellar movement of the motile bacteria. Use of sliced blood agar was superior to conventionally streaked blood agar in that (i) it was easier to see strong beta-hemolysis on sliced agar; (ii) frequently, a confirmatory diagnosis could be made using only one petri dish with sliced agar, thereby saving time and media; (iii) S. hyodysenteriae could sometimes be isolated free of other bacteria; and (iv) sliced agar was more effective in isolating S. hyodysenteriae from swine with chronic diarrhea and nondiarrhetic carriers of SD in which the shedding of S. hyodysenteriae was low.

Agar↗
PubMed1995

Survival of Serpulina hyodysenteriae in an effluent lagoon.

OBJECTIVE: To determine the survival of Serpulina hyodysenteriae in an infected lagoon that received effluent from a confinement building housing swine dysentery-infected swine. DESIGN: Prospective controlled trial. ANIMALS: 48 shedder swine inoculated with S hyodysenteriae and housed in the building drained by the lagoon; 18 clinically normal detector swine confined in a separate building. PROCEDURE: Shedder swine were inoculated with S hyodysenteriae by oral administration of 20 g of diced colon from swine infected with swine dysentery. The lagoon that received effluent from the building housing the shedder swine was assayed for S hyodysenteriae by providing lagoon effluent twice daily for 2 or 4 days to detector swine as their sole source of drinking water and by subsequently examining these swine for signs of swine dysentery. Smears from rectal swab specimens and sometimes fecal specimens were stained for detection of large spirochetes. Fecal and rectal swab specimens and colonic scraping specimens were examined for S hyodysenteriae by anaerobic microbial culture on blood agar containing 400 micrograms of spectinomycin/ml. All shedder swine were necropsied after removal from the confinement building, as were detector swine after developing diarrhea or after 42 days of monitoring. RESULTS: For the first 5 to 6 days after removal of swine dysentery-infected shedder swine from the confinement building, lagoon effluent from the building remained infective. Detector swine, given lagoon effluent as their drinking water for a 2-day period, developed clinical swine dysentery, and S hyodysenteriae was cultured from specimens from these swine. Swine dysentery did not develop in each group of 2 detector pigs given lagoon effluent as their sole source of drinking water on days 7 and 8, 9 and 10, 11 through 14, or 15 through 18 after removal of the infected shedder swine. Large spirochetes were not observed on microscopy of stained colonic scraping specimens, and S hyodysenteriae and Salmonella spp were not cultured from specimens from these detector swine after being monitored for 42 days. Serpulina hyodysenteriae or Salmonella spp were not cultured from samples of the lagoon effluent. CLINICAL IMPLICATIONS: Although many factors could influence the survivability of S hyodysenteriae in a lagoon, results suggested that a facility with an open gutter-flush system that housed swine dysentery-infected swine should remain idle for more than 5 to 6 days before repopulating with unexposed swine.

Animals↗
PubMed1994

Time dependencies in the occurrences of epileptic seizures.

A new method of analysis, developed within the framework of nonlinear dynamics, is applied to patient recorded time series of the occurrence of epileptic seizures. These data exhibit broad band spectra and generally have no obvious structure. The goal is to detect hidden internal dependencies in the data without making any restrictive assumptions, such as linearity, about the structure of the underlying system. The basis of our approach is a conditional probabilistic analysis in a phase space reconstructed from the original data. The data, recorded from patients with intractable epilepsy over a period of 1-3 years, consist of the times of occurrences of hundreds of partial complex seizures. Although the epileptic events appear to occur independently, we show that the epileptic process is not consistent with the rules of a homogeneous Poisson process or generally with a random (IID) process. More specifically, our analysis reveals dependencies of the occurrence of seizures on the occurrence of preceding seizures. These dependencies can be detected in the interseizure interval data sets as well as in the rate of seizures per time period. We modeled patient's inaccuracy in recording seizure events by the addition of uniform white noise and found that the detected dependencies are persistent after addition of noise with standard deviation as great as 1/3 of the standard deviation of the original data set. A linear autoregressive analysis fails to capture these dependencies or produces spurious ones in most of the cases.

Adult↗
PubMed1994

Treatment of group E streptococci-induced lymphadenitis in swine by feeding various concentrations of chlortetracycline: relation of antibody with prevalence of abscesses.

Consumption of chlortetracycline (CTC) at concentration of 220 mg/kg of feed for 4 weeks in experiment 1 and at concentrations of 110 and 220 mg/kg for 3 weeks and 440 mg/kg for 2 weeks in experiment 2 failed to eliminate streptococci-induced lymphadenitis from swine referred to as principals. Abscesses, mostly in the head and neck, developed in at least a third of all swine in the various groups fed these CTC concentrations. Feeding of 220 mg of CTC/kg of feed in experiment 1 began 12 weeks after exposure of principals to an untypeable group E streptococci (GES; isolate 3X29A). In experiment 2, feeding of 110 and 220 mg of CTC/kg of feed began 5 weeks after exposure of principals to GES and feeding of 440 mg of CTC/kg of feed began 6 weeks after exposure. One or more cohabitating sentinel swine of experiment 1 and one or more sentinels in all groups of principals of experiment 2, except group 2, developed abscesses that were mostly in the head and neck. In experiment 2, correlation between serum GES antibody titer and development of one or more abscesses in the principals was highly significant (P < 0.01); however, correlation between antibody titer and abscesses in the sentinels only approached significance (P < 0.10).

Abscess↗
PubMed1994

Exacerbated onset of dysentery in swine vaccinated with inactivated adjuvanted Serpulina hyodysenteriae.

After oral challenge exposure with Serpulina hyodysenteriae-infected diced colon, fewer swine vaccinated with an experimental vaccine adjuvanted with mineral oil died (8 of 25 [32%]) than did nonvaccinated controls (6 of 15 [40%]), although the difference was not significant. However, onset and exacerbation of dysentery were accelerated in vaccinated swine because: 5 of the 8 dead vaccinated swine died before any of the nonvaccinates, which was significant (P < 0.01); vaccinated swine that died were observed to have more hemorrhage in the feces, colonic mucosa, and colonic lumen than did nonvaccinated swine; and the earlier diarrhea onset in vaccinates, the more days of hemorrhagic diarrhea (P < 0.05). Antibody titer in vaccinated swine immediately before challenge exposure that subsequently died was significantly (P < 0.05) higher than that in vaccinated swine that recovered. Of of the 30 swine vaccinated with the experimental vaccine, 20 had dispersed droplets of mineral oil at the site of vaccination in the neck muscles and 3 swine had purulent abscesses at the injection site. It was concluded that vaccination with the experimental vaccine for controlling swine dysentery was ineffective.

Animals↗
PubMed1993

Experience with a planned exposure program for the control of enzootic transmissible gastroenteritis in swine.

Oral inoculation of pregnant sows and gilts with a homogenate of pig intestines containing live, virulent transmissible gastroenteritis (TGE) virus was associated with significant (P < 0.01) reduction of mortality in nursery pigs in a herd affected with enzootic TGE. The mortality of weaned pigs from April through June 1981, when sows were not vaccinated or inoculated, was 9.3%. Mortality of weanling pigs from July through December 1981 was 5.7% (P < 0.01), and stayed consistently between 2.6 and 4.8% from 1982 through 1990. After beginning the exposure program, there were no clinical signs attributable to TGE in the farrowing house or nursery until 1986, when recrudescence of TGE was evident in the nursery. Although the source of the virus could not be substantiated, recrudescence suggested that TGE virus would not be eradicated as long as exposure was continued. The most plausible explanation for the decrease in the incidence of diarrhea and mortality in the nursery pigs after initiation of the planned exposure program is that a higher, longer lasting amount of lactogenic immunity was provided to suckling pigs. Presumably over time, this resulted in less TGE virus carryover into the nursery by weanling pigs, thereby reducing and confining the environmental challenge to the nursery. Strict all-in, all-out pig movement in the nursery with thorough cleaning and disinfecting presumably further reduced the environmental challenge.

Administration, Oral↗
PubMed1993

Arginine utilization by Mycoplasma fermentans is not regulated by glucose metabolism: a 13C-NMR study.

13C-NMR studies on the effect of glucose metabolism on arginine hydrolysis in Mycoplasma fermentans cells have been performed using a continuous perfusion technique. With this procedure we were able to show, in the presence of glucose, the rapid accumulation of lactic acid and, in the presence of arginine, the formation of citrulline that is apparently further metabolized. As the accumulation of lactate and the breakdown of arginine were observed in the simultaneous presence of both substrates, it is suggested that the glucose utilization has little or no effect on the deimination of arginine to citrulline.

Arginine↗
PubMed1993

Characteristics of Mycoplasma hominis adhesion.

Mycoplasma hominis, a human pathogen, has previously been observed to bind to sulfatide separated on thin-layer chromatograms. It has not been demonstrated, however, that the binding is not simply a nonspecific ionic interaction. The ability of a low-passage patient isolate of M. hominis to adhere to glycoconjugates other than sulfatide and the characteristics of its binding to sulfatide were studied. Mycoplasmas were found to bind strongly and specifically in a temperature- and dose-dependent manner to only sulfatide of all of the glycolipids and glycoproteins tested. The avidity and specificity of binding, as well as the ability to inhibit the interaction specifically, suggest that the receptors to which M. hominis binds, particularly in the human urogenital tract, from which it is frequently isolated, are primarily, if not solely, sulfated glycolipids.

Bacterial Adhesion↗
PubMed1992

Incorporation of radiophosphorus from labeled oligodeoxynucleotides into RNA of mycoplasma in cell cultures.

We have found that various mycoplasma species quickly and efficiently incorporate radiophosphorus into their RNA from labeled oligonucleotides added to the medium. The label can be in any of several positions in an oligodeoxynucleotide, and incorporation also occurs efficiently from labeled RNA. Mycoplasmas also incorporate the radiolabel when they infect a mammalian cell culture; the host cells do not. This incorporation presumably involves uptake of the oligodeoxynucleotide followed by digestion to mononucleotides, conversion to ribonucleotides, and incorporation in new RNA. We believe that the processing of oligodeoxynucleotides by mycoplasma could be a source of artifacts in antisense work in cell culture and could have implications for the development of antisense therapeutics. We also suggest ways to exploit the incorporation phenomenon in mycoplasma testing.

Adenosine Triphosphate↗
PubMed1991

Stepwise determination of multicompartment disposition and absorption parameters from extravascular concentration-time data. Application to mesoridazine, flurbiprofen, flunarizine, labetalol, and diazepam.

When disposition is monoexponential, extravascular concentration-time (C, t) data yield both disposition and absorption parameters, the latter via the Wagner-Nelson method or deconvolution which are equivalent. Classically, when disposition is multiexponential, disposition parameters are obtained from intravenous administration and absorption data are obtained from extravascular C, t data via the Loo-Riegelman or Exact Loo-Riegelman methods or via deconvolution. Thus, in multiexponential disposition one assumes no intrasubject variation in disposition, a hypothesis that has not been proven for most drugs. Based on the classical two- and three-compartment open models with central compartment elimination, and using postabsorptive extravascular C, t data only, we have developed four equations to estimate k10 when disposition is biexponential and two other equations to estimate k10 when disposition is triexponential. The other disposition rate constants are readily obtained without intravenous data. We have analyzed extravascular data of flurbiprofen (12 sets), mesoridazine (20 sets), flunarizine (5 sets), labetalol (9 sets), and diazepam (4 sets). In the case of diazepam intravenous C, t data were also available for analysis. After disposition parameters had been estimated from the extravascular data the Exact Loo-Riegelman method with the Proost modification was applied to the absorptive extravascular data to obtain AT/VP as a function of time. These latter data for each subject and each drug studied were found to be fitted by a function indicating either simple first-order absorption, two consecutive first-order processes, or zero-order absorption. After absorption and disposition parameters had been estimated, for each set of extravascular data analyzed, a reconstruction trend line through the original C, t data was made. The new methods allow testing of the hypothesis of constancy of disposition with any given drug. There is also a need for new methods of analysis since the majority of drugs have no marketed intravenous formulation, hence the classical methods cannot be applied.

Algorithms↗
PubMed1991

Monoclonal antibodies to surface antigens of a pathogenic Mycoplasma hominis strain.

Three monoclonal antibodies (MAbs) were prepared against an arthritogenic strain of Mycoplasma hominis isolated from the joint aspirates of a patient with chronic septic arthritis. Immunoblots of polyacrylamide gel-electrophoresed proteins before and after surface proteolysis showed that the predominant antigenic determinants were on surface-exposed polypeptides. These polypeptides have extensive hydrophobic characteristics, as demonstrated by Triton X-114 phase partitioning. The electrophoresed proteins from cells grown in medium containing [14C]palmitate were blotted onto nitrocellulose which was both reacted with the MAbs and exposed to X-ray film. Superimposable bands on both the immunoblots and the exposed film suggested that the proteins might be acylated. The MAbs were further tested for reactivity with 16 other strains of M. hominis isolated from patients with septic arthritis (1 strain), septicemia (10 strains), or nongonococcal urethritis (1 strain); from the cervix (1 strain), rectum (1 strain), or surgical wound (1 strain) of patients; and from a contaminated cell culture. No single protein was consistently recognized from strain to strain, although a 94-kDa protein from 16 of the 17 strains tested was bound by at least one of the MAbs. The apparent antigenic heterogeneity among strains of M. hominis, including those isolated from the same tissue source and/or from patients with the same type of clinical disease, might be misleading in that all strains express epitopes associated with a discrete number of proteins to which one, two, or all three MAbs bind. The expression of the epitopes on multiple proteins from the same or different strains may reflect a mechanism for generating antigenic diversity.

Animals↗
PubMed1991

Successive synovial Mycoplasma hominis isolates exhibit apparent antigenic variation.

The expression of surface proteins by 14 successive Mycoplasma hominis isolates obtained from the synovial fluid of a chronically infected septic arthritis patient was examined. Marked differences in the expression of surface proteins, as determined by monoclonal antibodies raised against the first isolate, were observed. However, identical restriction patterns and virtually identical hybridization patterns with probes containing the conserved genes of the Mycoplasma capricolum rRNA operon and the Escherichia coli elongation factor Tu suggest that the protein differences might reflect antigenic variation by M. hominis during infection.

Antibodies, Monoclonal↗
PubMed1991

Analysis of Mycoplasma hyorhinis DNA in the presence of host cells without growing the mycoplasma axenically.

Mycoplasma hyorhinis coisolates with the mitochondria of the cells in which it is carried as an infection. Since both mitochondria and mycoplasmas synthesize DNA by using the prokaryotic DNA polymerase gamma, the use of aphidicolin, which inhibits eukaryotic DNA polymerase alpha, allows for selective synthesis of mycoplasmal and mitochondrial DNA. The restriction patterns of mitochondria and mycoplasmas can easily be differentiated from each other in mixtures of both DNAs. Thus, it is possible to study the molecular biology of this noncultivable mycoplasma in situ rather than after growth in artificial media, with its potential genetic consequences during adjustment to axenic growth.

Animals↗
PubMed1989

Adhesion of Mycoplasma pneumoniae to sulfated glycolipids and inhibition by dextran sulfate.

A virulent strain of Mycoplasma pneumoniae was metabolically labeled with [3H]palmitate and studied for binding to glycolipids and to WiDr human colon adenocarcinoma cells. The organism binds strongly to sulfatide and other sulfated glycolipids, such as seminolipid and lactosylsulfatide which all contain terminal Gal(3SO4) beta 1-residues and weakly to some neolactoseries neutral glycolipids. M. pneumoniae do not bind gangliosides including the sialylneolacto-series and other neutral glycolipids that were tested. Only metabolically active M. pneumoniae cells bind to sulfatide, as binding is maximal in RPMI medium at 37 degrees C and almost completely abolished in nutrient-deficient medium or by keeping the cells at 4 degrees C. Dextran sulfate but not other sulfated or anionic polysaccharides at 10 micrograms/ml completely inhibits binding of M. pneumoniae to purified sulfatide. Dextran sulfate does not inhibit binding to the neolacto-series neutral glycolipids. Dextran sulfate partially inhibits adhesion of M. pneumoniae to cultured human colon adenocarcinoma cells (WiDr). The biological relevance of these data is suggested by our finding that sulfatide occurs in large amounts in human trachea, lung, and WiDr cells. Thus, there are at least two distinct receptors that mediate binding of M. pneumoniae to cells: glycolipids containing terminal Gal(3SO4) beta 1-residues as reported here, and glycoproteins containing terminal NeuAc alpha 2-3Gal beta 1-4GlcNAc sequences (Roberts, D. D., Olson, L. D., Barile, M. F., Ginsburg, V., and Krivan, H. C. (1989) J. Biol. Chem. 264, 9289-9293).

Animals↗
PubMed1989

Sialic acid-dependent adhesion of Mycoplasma pneumoniae to purified glycoproteins.

Several purified glycoproteins including laminin, fetuin, and human chorionic gonadotropin promote dose-dependent and saturable adhesion of Mycoplasma pneumoniae when adsorbed on plastic. Adhesion to the proteins is energy dependent as no attachment occurs in media without glucose. Adhesion to all of the proteins requires sialic acid, and only those proteins with alpha 2-3-linked sialic acid are active. The alpha-subunit of human chorionic gonadotropin also promotes attachment, suggesting that a simple biantennary asparagine-linked oligosaccharide is sufficient for binding. Soluble laminin, asparagine-linked sialyloligosaccharides from fetuin, and 3'-sialyllactose but not 6'-sialyllactose inhibit attachment of M. pneumoniae to laminin. M. pneumoniae also bind to sulfatide adsorbed on plastic. Dextran sulfate, which inhibits M. pneumoniae binding to sulfatide, does not inhibit attachment on laminin, and 3'-sialyllactose does not inhibit binding to sulfatide, suggesting that two distinct receptor specificities mediate binding to these two carbohydrate receptors. Both 3'-sialyllactose and dextran sulfate partially inhibit M. pneumoniae adhesion to a human colon adenocarcinoma cell line (WiDr) at concentrations that completely inhibit binding to laminin or sulfatide, respectively, and in combination they inhibit binding of M. pneumoniae to these cells by 90%. Thus, both receptor specificities contribute to M. pneumoniae adhesion to cultured human cells.

Animals↗
PubMed1989

Biological activities of monoclonal antibodies to Mycoplasma pneumoniae membrane glycolipids.

A purified preparation of membranes was obtained by using a unique method of treating Mycoplasma pneumoniae with the ATPase inhibitor, diethylstilbestrol. This method was shown to yield highly purified membranes with little or no cytoplasmic contamination. These membranes were used to immunize mice for subsequent productions of monoclonal antibodies (MAbs). Hybridoma culture supernatants were screened by enzyme-linked immunosorbent assay with whole-cell M. pneumoniae and lipid extract antigens. Four stable MAbs were obtained and characterized. MAb CP3-46F5 reacted with a protein of a molecular weight of approximately 52,000 as determined by Western blot (immunoblot). MAbs CP3-50C2, CP3-53C5, and CP3-53C8 did not react with any antigens on Western blots but did bind to at least 10 distinct glycolipid bands as determined by orcinol staining on thin-layer chromatograms of M. pneumoniae lipid extracts. The MAbs did not react with similarly prepared lipid extracts from Mycoplasma genitalium, Mycoplasma neurolyticum, and Mycoplasma gallisepticum. These MAbs did not inhibit M. pneumoniae metabolism or attachment to WiDr cell cultures. The anti-glycolipid MAbs recognize determinants specific to M. pneumoniae, unlike polyclonal hyperimmune sera against M. pneumoniae, which cross-react with lipid extracts of M. genitalium.

Animals↗
PubMed1989

Clinical evaluation of transmissible gastroenteritis virus vaccines and vaccination procedures for inducing lactogenic immunity in sows.

Two federally licensed attenuated live transmissible gastroenteritis (TGE) virus vaccines (an IM vaccine and an oral-IM vaccine) and 1 nonlicensed nonattenuated live TGE virus vaccine were evaluated and compared in sows free of TGE virus-neutralizing antibodies. Litters from the sows were challenge exposed at 3 and 5 days of age, and results were combined according to the vaccine administered to the sows. The survivability of pigs suckling sows vaccinated with the nonattenuated vaccine was significantly (P less than 0.01) greater than that of pigs suckling sows vaccinated with the IM attenuated vaccine, significantly (P less than 0.05) greater than that of pigs suckling sows vaccinated with the oral-IM attenuated vaccine, and significantly (P less than 0.05) greater than that of pigs suckling sows that had not been vaccinated. The differences, however, between survivability of litters from sows vaccinated with the IM attenuated vaccine or the oral-IM attenuated vaccine and that of litters from the sows not vaccinated were not significant (P greater than 0.10). The nonattenuated TGE vaccine, although giving a higher level of protection than the attenuated vaccine, was eventually overwhelmed. Dexamethasone did not increase the incidence of diarrhea, and levamisole did not potentiate the lactogenic immunity in sows after given their first dose of the nonattenuated vaccine. Survivability in litters suckling sows that developed diarrhea after given their first dose of the nonattenuated vaccine was not greater than that in litters suckling sows that did not develop diarrhea. The best results were obtained when 3-day-old suckling pigs were challenge exposed with virulent TGE virus.

Animals↗