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PubMedDate not supplied

Electropherotypic analysis of rotaviruses isolated from turkeys.

From 1980 to 1984, several flocks of turkeys in Minnesota exhibiting signs of clinical enteritis were examined for viruses. Electron microscopic (EM) examination of fecal specimens from 35 flocks revealed the presence of rotavirus particles. Rotaviruses were successfully isolated in cell cultures from only 24 of these positive fecal specimens. Double-stranded RNA (dsRNA) preparations made from these 24 cell-culture isolates and from the remaining 11 fecal samples that were rotavirus-positive on EM examination were analyzed by polyacrylamide gel electrophoresis for genetic differences in their genomes. The study revealed eight distinct electropherotypes among the rotavirus dsRNA preparations. Atypical dsRNA migration patterns were recognized only in preparations of dsRNA from fecal materials.

Animals↗
PubMed1988

Background (spontaneous) immunoglobulin production in the murine small intestine as a function of age.

The development of the intestinal B-cell compartment in C3H/He mice was studied as a function of age by quantification of the number of intestinal immunoglobulin-secreting cells (Ig-SC). Before and at weaning, the number of Ig-SC in the small intestine (SI) was below 10(3) Ig-SC per SI. During the first few weeks after weaning, this number rose steeply and continued to rise until the mice were about 48 weeks old, when a maximum of more than 25 x 10(6) Ig-SC per SI was found. After 1 year of age the number of Ig-SC decreased. At all ages, the great majority of Ig-SC in the SI produced IgA. The increase of the number of IgA-SC in the SI after weaning is reflected in the amount of IgA in intestinal secretions measured by ELISA. The number of Ig-SC in the SI was compared with the number of Ig-SC found in spleen, bone marrow, Peyer's patches and mesenteric lymph nodes. Striking differences were observed between the SI and the other organs tested in total number, isotype distribution and kinetics of the increase of Ig-SC during ontogeny. These differences are discussed in relation to the regulation of the immune response in the SI and the migration patterns of lymphocytes in mucosal tissues.

Aging↗
PubMed1988

Field inversion gel electrophoretic separation of Cryptosporidium spp. chromosome-sized DNA.

Chromosomal DNA from 5 isolates of Cryptosporidium parvum and 1 of C. baileyi were compared by field-inversion gel electrophoresis (FIGE). FIGE analyses of parasite DNA prepared from purified sporozoites versus intact oocysts showed no observable differences. Chromosomal DNA migration patterns of the 5 C. parvum isolates were indistinguishable, whereas similar but distinct differences were evident between C. baileyi and the isolates of C. parvum. Oocyst-reactive monoclonal antibodies differentiated oocysts of C. parvum from those of C. baileyi but were unable to distinguish oocysts of 1 isolate of C. parvum from another.

Animals↗
PubMed1988

Schistosoma malayensis n. sp.: a Schistosoma japonicum-complex schistosome from Peninsular Malaysia.

Schistosoma malayensis n. sp., a member of the Schistosoma japonicum complex is described from Rattus muelleri in Peninsular Malaysia and 2 strains are characterized. The only morphological differences noted among adults from natural hosts were that S. malayensis are in general smaller than S. mekongi and S. japonicum. But these differences may be the result of host-induced variations and therefore are of little taxonomic value. To minimize the effects of host-induced variations, adult worms recovered from laboratory mice with similar worm burdens at 50-56 days postinfection were compared. These comparisons revealed only minor morphometric differences among these 3 species. Schistosoma malayensis eggs from naturally and experimentally infected hosts are most similar to those of S. mekongi, with eggs of both species being, in general, smaller than those of S. japonicum. The egg index for S. malayensis is usually higher than for S. japonicum and lower than for S. mekongi. Differences were noted in the developmental rates in mice for 2 isolates of S. malayensis, S. mekongi, and S. japonicum (Philippine strain), but relatively large differences observed between isolates of S. malayensis indicate that, in this case, the developmental rate is not a useful taxonomic character. Schistosoma malayensis is erected principally on the basis of differences, reported elsewhere, in the life histories and in the electrophoretic migration patterns of isoenzymes of adult worms as compared to S. mekongi and S. japonicum. These comparisons indicate that S. malayensis is more closely related to S. mekongi than to S. japonicum.

Animals↗
PubMed1986

Occupations, migration, sex ratios, and nuptiality in nineteenth century English communities: a model of relationships.

Two effects of occupational structure on nuptiality levels are examined: a direct functional effect related to the influence of socioeconomic characteristics on the feasibility and desirability of marriage, and an indirect structural effect related to nuptiality levels via sex selective migration patterns and population sex ratios. Our analysis shows that nuptiality levels in nineteenth century English and Welsh districts were responsive to occupational variation and that both direct and indirect effects were significant. Our results suggest that socioeconomic factors, often overlooked in favor of cultural explanation, must be considered in the analysis of nuptiality.

Emigration and Immigration↗
PubMed1986

Membrane-associated glycoprotein (gp 160) identified on human lung tumors by a monoclonal antibody.

A monoclonal antibody (5E8) has been used to identify and structurally characterize a previously unreported macromolecule present on the surface of human lung tumors. This antibody was derived from a hybrid clone that was produced using spleen cells of mice immunized with a surgically excised squamous cell carcinoma. Using immunofluorescence, the 5E8 antibody was observed to stain many different human lung tumor cell lines and surgically excised human lung tumors including squamous cell carcinomas, adenocarcinomas, alveolar carcinomas, and a portion of the large cell tumors tested. With few exceptions, notably the basal layer of the skin, little or no detectable staining of 5E8 to normal human tissues (lung, brain, kidney, heart, stomach, breast, erythrocytes, or lymphocytes) was observed. The 5E8 antibody was used to immunoprecipitate detergent lysates of biosynthetically labeled or surface radioiodinated lung tumors. Analysis of the immunoprecipitates by sodium dodecyl sulfate gel electrophoresis revealed a major band and a faster migrating second minor band. The molecular weights of these two proteins were estimated to be 160,000 and 120,000, respectively. The addition of a reducing agent to the gels did not alter the migration pattern of the immunoprecipitated macromolecules. The removal of a terminal carbohydrate, sialic acid, did not restrict the binding of 5E8 to the tumor-associated antigen. However, labeling studies using galactose oxidase and tritiated borohydride revealed the presence of galactose on the immunoprecipitated protein. This major Mr 160,000 glycoprotein that was identified on two different human lung tumor cell lines was also found on a human large cell tumor tissue obtained by surgical biopsy. The 5E8 antibody and the Mr 160,000 glycoprotein that it recognizes represent two very useful components with which to test several new antibody-mediated drug delivery systems in the treatment of human lung tumors. The tumor-associated glycoprotein also represents a potential analyte for a diagnostic or prognostic immunoassay for lung cancer.

Antibodies, Monoclonal↗
PubMed1987

[A complex medico-genetic study of West Siberian populations. I. Formulation of a problem. Goals and objectives of the study. Population genetic characteristics of Northern Khanty].

Purposes and tasks of the complex medical and genetic study of West-Siberian inhabitants were formulated. Demographic parameters for the North Khanty inhabitants, such as size, dynamics of the tertiary sex ratio, marriage structure and migration processes were presented. Mating and intrapopulation migration patterns are determined by spatial subdivision, because of the vast territory and the traditional way of life, and by isolation by distance. Index of the isolocal endogamy equals to 0.364. The portion of mixed marriages is 22.7% and that of the gametic contribution of immigrants - 7.3%. Inbreeding coefficient by isonymy is 0.00097. Effective population size of the five subpopulations studied as a whole is 25% of their total number.

Consanguinity↗
PubMed1987

Phosphorylation of caldesmon77 by protein kinase C in vitro and in intact human platelets.

Caldesmon is a widely distributed calmodulin- and actin-binding protein which occurs in different forms depending on the tissue or cell type under examination. On the basis of molecular weight, caldesmon species can be divided into two classes: caldesmon77 (Mr 70,000-80,000) and caldesmon150 (Mr 140,000-150,000). We have examined the phosphorylation of caldesmon77 by protein kinase C (the Ca2+/phospholipid-dependent enzyme) in vitro and in intact platelets. Caldesmon77, purified from bovine liver, could be phosphorylated by purified rat brain protein kinase C to a level of approximately 1.0 mol of phosphate per mol of caldesmon77 monomer. Two-dimensional tryptic peptide mapping and phosphoamino acid analysis reveals that caldesmon77 is phosphorylated at two major sites exclusively on serine residues. Following treatment of platelets with tumor-promoting phorbol ester, caldesmon77 phosphorylation was elevated 4-fold. Tryptic peptide mapping of phosphorylated platelet caldesmon77 demonstrates that phosphorylation is most significantly enhanced on two peptides which had migration patterns identical with those of the two major phosphopeptides of bovine liver caldesmon77 phosphorylated in vitro. The results of this study indicate that protein kinase C can phosphorylate caldesmon77 in vitro and in intact platelets, suggesting a role for protein kinase C in the regulation of caldesmon77 function or localization.

Animals↗
PubMed1986

Application of polyacrylamide gel electrophoresis of genome fragments to control of reovirus products.

The reoviridae are notable for their genome consisting of 10 to 12 pieces of double-stranded RNA. The migration pattern of these pieces produced by polyacrylamide gel electrophoresis has been used by other workers as a means of identifying these viruses for epidemiology or classification. This paper reports attempts by the authors to apply this technique to various aspects of control of reovirus products, with a view to supplementing or replacing techniques involving animals. The findings are discussed in relation to those of other workers.

Electrophoresis, Polyacrylamide Gel↗
PubMed1985

Recombinant interleukin 2 stimulates in vivo proliferation of adoptively transferred lymphokine-activated killer (LAK) cells.

We previously reported that the adoptive transfer of lymphokine-activated killer (LAK) cells plus repetitive injections of recombinant interleukin 2 (IL 2) produced a marked reduction in established pulmonary metastases from a variety of murine sarcomas. The requirement for the exogenous administration of IL 2 prompted a subsequent examination of the role of IL 2 in the in vivo function of transferred LAK cells. The in vivo proliferation and migration patterns of lymphoid cells in C57BL/6 mice were examined after i.v. transfer of LAK cells alone, i.p. injection of IL 2 alone, or the combination of LAK cells and IL 2. A model for in vivo labeling of the DNA of dividing cells was used in which mice were injected with 5-[125I]-iodo-2'-deoxyuridine (125IUdR) and, 20 hr later, their tissues were removed and were counted in a gamma analyzer. A proliferation index (PI) was calculated by dividing the mean cpm of organs of experimentally treated mice by the mean cpm of organs of control mice. In animals given LAK cells alone, the lungs and liver demonstrated little if any uptake of 125IUdR above saline-treated controls (PI = 2.5 and 0.8, respectively, on day 5), whereas the same organs of mice receiving 6000 U of IL 2 alone displayed higher radiolabel incorporation (PI = 7.1 and 5.9, respectively). When mice were given LAK cells plus 6000 U of IL 2, their tissues showed an additional increase in 125IUdR uptake. In the spleen, kidneys, and mesenteric lymph nodes, IL 2 treatment alone (6000 U) produced elevated PI values that were not, however, additionally increased if LAK cells were also administered. To separate the stimulatory effects of IL 2 on host lymphocyte proliferation from similar IL 2 effects on injected LAK cells, these studies were repeated in mice immunosuppressed by 500 rad total body irradiation. Pre-irradiation of the host sufficiently reduced endogenous lymphoid expansion stimulated by IL 2 so as to allow the demonstration that IL 2 also induced the proliferation of the transferred LAK cells. A variety of studies confirmed that the injected LAK cells were actively proliferating in tissues in vivo under the influence of IL 2. Substitution of "normal" LAK cells with fresh and cultured (without IL 2) splenocytes, or irradiated LAK cells did not result in increased 125IUdR uptake in tissues. Histologic studies corroborated the findings of the 125IUdR incorporation assays and revealed extensive lymphoid proliferation in irradiated mice receiving LAK cells plus IL 2.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1985

Comparison of bacteriostatic and bactericidal inhibitors of Neisseria gonorrhoeae growth produced in vitro by urogenital staphylococci.

Coagulase-negative staphylococci are known to produce bactericidal and bacteriostatic antigonococcal activities. Out of 12 staphylococci, Staphylococcus haemolyticus (four isolates) was identified as the principal source of bactericidal activity, whereas Staphylococcus epidermidis (six isolates) was primarily responsible for producing bacteriostatic activity. A comparison of the bacteriostatic substance produced by S. epidermidis isolate 66 with the bactericidal substance produced by S. haemolyticus isolate 7, which had been previously purified, showed that they were similar lipoproteins or lipid-associated proteins. However, these two inhibitors migrated differently under electrophoresis on agarose gel. The protein component of the bacteriostatic inhibitor was more difficult to separate from the lipid component when chromatographed on Ultrogel AcA 54 in the presence of urea (4 M) than the protein component of the bactericidal inhibitor. The protein component of both types of inhibitors was responsible for the antigonococcal activity and was dissociable into subunits of approximately 1,400 daltons. However, these protein components had different migration patterns on agarose gel. The bacteriostatic substance displayed a bactericidal effect when dissociated from its lipidic component suggesting that the lipids might play a role in the type of inhibitory activity produced. All of the bactericidal and bacteriostatic substances contained in the different crude preparations were antigenically related.

Animals↗
PubMed1986

Plasmid profiles of Moraxella bovis isolates.

Two-hundred isolates of Moraxella bovis were selected at random and examined for the presence of plasmid DNA by a rapid alkaline-detergent lysis method. All isolates contained from 1 to 6 plasmids, with varying agarose-gel electrophoretic migration patterns. Most (80%) isolates carried 2 to 4 plasmids, which ranged in molecular weight from 2.6 to 80 megadaltons. Seemingly, plasmid profiles can be used as a simple, reliable epizootiologic tool to establish a strain identification scheme for M bovis.

Animals↗
PubMed1977

[Determination of the molecular weight of vitellogenin and of lipovitellins of Orchestia gammarella, Crustacea, Amphipoda].

Vitellogenin and lipovitellins of Orchestia gammarella, tested by electrophoresis on gels of different acrylamide concentrations, following the procedure of Hedrick and Smith (1968), displays a migration pattern identical to that of proteins of respectively congruent to 4 x 10(5) (vitellogenin), congruent to 3,5 x 10(5) (lipovitellins I and I') and congruent to 5 x 10(5) (lipovitellin II) molecular weights.

Animals↗
PubMed1978

The effect of an immune RNA (RNAi) against Trypanosoma cruzi infection in mice.

Immune ribonucleic acid (RNAi) was extracted with phenol from the spleen of mice immunized with the avirulent PF strain of Trypanosoma cruzi. These preparations were able to induce immunocompetent cells to answer as a secondary response to later challenges with the virulent Y strain of the same parasite. The preparations of RNAi were"immunogenic" and free of proteins. The RNAi preparations were sensitive to pancreatic RNAase and lost their immune effect when pretreated with this enzyme. The injections of normal RNA (RNAn) obtained by the same method showed that this polymer acts as an immuno supressor or competitive agent. The electrophoretic profiles of the RNAi preparations in polyacrylamide gels showed normal and characteristic migration patterns (28S, 18S and 4.5S). These results demonstrate the development of an immune state against T. cruzi infection in mice injected with RNAi, in the absence of living parasites.

Animals↗
PubMed1975

Maturation of B lymphocytes in the rat. II. Subpopulations of virgin B lymphocytes in the spleen and thoracic duct lymph.

Thoracic duct and spleen cells of normal (unimmunized) adult rats were fractionated according to size by 1 times G velocity sedimentation. Fractions were tested for their ability to restore the adoptive antibody response of irradiated hosts to horse spleen ferritin. A constant source of T cells (small numbers of unfractionated thoracic duct cells) was added to each fraction in order to monitor the B cell activity of the latter. Although large and small cell fractions of the spleen showed restorative activity, only the small cell fractions of the thoracic duct lymph showed activity. The turnover rate of the spleen cell fractions was determined by treating donors with high specific-activity 3H-thymidine for 48 hr before splenectomy. Rapidly dividing cells are preferentially killed by this treatment. The results suggest that a considerable proportion of large, intermediate, and small virgin B cells turn over within 48 hr. The cell surface of the various spleen cell fractions was examined for the presence of immunoglobulin (Ig) and a receptor for complement. The percentage of Ig-bearing cells in the large cell fractions was similar to the percentage of cells bearing IgM and a receptor for complement. However, the majority of Ig-bearing cells in the small cell fractions did not show the latter two surface markers. Experiments with the fluorescence-activated cell sorter showed that the large functionally active B cells bore surface IgM. The experimental findings suggest that there are subpopulations of virgin B cells in the spleen of the adult rat which differ with respect to size, migration pattern, turnover rate, and cell surface characteristics. The relationship of these cells to one another is discussed in the framework of an antigen-independent model of B cell maturation in the rat.

Animals↗
PubMed1979

Biophysical and serologic comparison of four equine adenovirus isolates.

Four equine adenovirus isolates have been characterized with regard to their biophysical and serologic properties. Electron microscopic studies demonstrated that purified virions have a typical adenovirus morphologic characteristic, with 50-nm-long fiber projections at each vertex of an 80-nm-diameter icosahedron. Extracted viral DNA was found to be a linear duplex of molecular weight 21 to 22 x 10(6). All four isolates were found to have a buoyant density in CsCl of 1.346 +/- 0.002 g/ml. Hexon structural components prepared from each isolate were shown to carry the same relative net charge, as judged from anion exchange elution profiles. Sodium dodecyl sulfate (sodium lauryl sulfate)-polyacrylamide gel electrophoresis revealed that the four isolates were composed of which the electrophoretic migration pattern was distinct from that of a human adenovirus reference. Serologic data (serum-neutralization and hemagglutination-inhibition tests) did not reveal any distinct antigenic diversity among the four isolates. On the basis of data obtained in this study, it is proposed that equine adenovirus isolates thus far available do, in fact, constitute a single serotype.

Adenoviridae↗
PubMedDate not supplied

Nucleic acid and structural proteins of infectious bursal disease virus isolates belonging to serotypes I and II.

The nucleic acid and structural proteins of infectious bursal disease virus serotype I (six isolates) were compared with those of serotype II (two isolates). Five of the serotype I isolates originated from chickens, whereas both serotype II isolates were from turkeys. The growth curves of representative isolates of both serotypes were similar, but the latent period and virus yield were different. The seven isolates tested had two segments of double-stranded genomic RNA. The RNA migration patterns of viruses belonging to each serotype were similar, but differences were noticed between the two serotypes. There were differences in the molecular weights of viral proteins (VP) 3 and 4 from the two serotypes, and serotype II isolates lacked VP-2.

Animals↗