scholarly journals AN HETEROPHILE FACTOR IN RAGWEED POLLEN

1940 ◽  
Vol 71 (5) ◽  
pp. 591-601 ◽  
Author(s):  
F. Eastty Sammis
Keyword(s):  
Blood Groups ◽  
Ragweed Pollen ◽  
Rabbit Serum ◽  
Total N ◽  
Heat Stable ◽  
Heat Labile ◽  
Forssman Antigen ◽  
Zones Of Inhibition ◽  
Antigen Antibody ◽  
Antibody Mixture

1. There is serological evidence that ragweed pollen antigen contains a factor which causes an increased hemolysin titre for sheep cells, when injected into rabbits. 2. It remains questionable whether the antigen absorbs normal rabbit hemolysins. It does, however, absorb anti-ragweed hemolysins, as demonstrated by hemolysis inhibition test. 3. Dilution and lyophilization (Mudd-Flosdorf method) of antigen-antibody mixture shows that one hemolytic unit of anti-ragweed rabbit serum combines with 0.00007 mg. of low ragweed total N. There were three zones of inhibition of hemolysis demonstrated. 4. The immune hemolysins are completely absorbed by sheep cells and by Forssman antigen, but not by human cells of groups A or B. 5. Although Forssman antigen was able to absorb anti-ragweed hemolysin, the ragweed antigen was not able to absorb Forssman antibody. 6. Human ragweed sensitive sera from 22 cases with hay fever, before treatment, did not show increased titre of heat-labile or heat-stable hemolysin. There was no change after treatment. 7. Among the human cases there were encountered blood groups A, B, and O. Heat-labile hemolysins for sheep cells were present in nineteen of the twenty-two sera regardless of blood groups.

scholarly journals Immunity to the group B streptococci: interaction of serum and macrophages with types Ia, Ib, and Ic.

1976 ◽  
Vol 143 (5) ◽  
pp. 1186-1198 ◽  
Author(s):  
B F Anthony
Keyword(s):  
Group B Streptococcus ◽  
Immune Serum ◽  
Normal Serum ◽  
Rabbit Serum ◽  
Group B Streptococci ◽  
Opsonic Activity ◽  
Heat Stable ◽  
Group B ◽  
Antigen Antibody

The opsonization and phagocytosis of group B streptococci of types Ia, Ib, and Ic were studied in vitro by measuring the uptake of radioactivity by coverslip cultures of rabbit alevolar macrophages during incubation with radiolabeled, nonviable bacteria which had been exposed to rabbit serum. The uptake of counts per minute was quantitative, reproducible, and reversibly inhibited by cold, indicating that it was largely a measurement of phagocytic ingestion rather than of attachment of bacteria-immunoglobulin complexes to macrophage membranes. Moreover, suspended macrophages killed approximately 90% of viable streptococci in the presence of specific antiserum. The opsonic activity of immune serum was heat stable, and phagocytosis of streptococci was insignificant after incubation with normal serum and antiserum to some heterologous group B streptococci. By absorption studies, it was possible to identify the effect of antibodies to specific bacterial antigens. Phagocytosis of streptococci containing the corresponding antigens was maximal after opsonization with homologous or heterologous sera containing antibody to IaCHO, IbCHO, or Ibc protein. Phagocytosis of all three serotypes was intermediate when opsonization could be attributed to anti-IabcCHO. The opsonization of a specific group B streptococcus is complex and may involve two or more antigen-antibody systems.

scholarly journals A HEMOLYTIC SYSTEM ASSOCIATED WITH ENTERITIS IN RABBITS

1963 ◽  
Vol 117 (4) ◽  
pp. 647-661 ◽  
Author(s):  
Robert S. Evans ◽  
Margaret Bingham ◽  
Russell S. Weiser
Keyword(s):  
Red Cells ◽  
Rabbit Serum ◽  
Normal Rabbit Serum ◽  
Red Cell ◽  
Heat Stable ◽  
Heat Labile

A disease characterized by frequent association of enteritis and polyagglutinable cells often develops in weanling rabbits. The red cell lesion renders the cells susceptible to agglutination and hemolysis in normal rabbit sera. The degree of red cell abnormality varies among different animals and disappears when the animals recover. The abnormality of the red cells responsible for their polyagglutinability and susceptibility to hemolysis was resistant to the action of trypsin or papain and persisted in heated stroma preparations derived from polyagglutinable cells. The factors necessary for agglutination and hemolysis of the polyagglutinable cells are present in normal rabbit sera but are lacking in the sera of affected rabbits. These factors returned to normal levels as the polyagglutinable cell lesion disappeared. The sera of rabbits with polyagglutinable cells contained normal levels of complement and properdin. Whereas the agglutinating factor in normal sera is heat-stable at 56°C for 30 minutes, the hemolytic factor is heat labile. The hemolytic factor is apparently distinct from complement and properdin since it was adsorbed from normal rabbit serum by zymosan or by polyagglutinable cells at 0°C. However, complement was fixed when normal rabbit serum was reacted with stroma from polyagglutinable cells. Hemolysis of polyagglutinable cells by normal rabbit serum at 25°C was inhibited by preliminary incubation of the mixture at 0°C prior to incubation at 25°C. Evidence was obtained which indicated that this inhibition was due to progression of a reaction involving Ca++ independent of a reaction involving Mg++.

Use of a Multiplex PCR System for the Simultaneous Detection of Heat Labile Toxin I and Heat Stable Toxin II Genes of Enterotoxigenic Escherichia coli in Skim Milk and Porcine Stool

1998 ◽  
Vol 61 (2) ◽  
pp. 141-145 ◽  
Author(s):  
HAU-YANG TSEN ◽  
LIANG-ZHAO JIAN ◽  
WAN-RONG CHI
Keyword(s):  
Escherichia Coli ◽  
Multiplex Pcr ◽  
Simultaneous Detection ◽  
Skim Milk ◽  
Pcr Primers ◽  
Enterotoxigenic Escherichia Coli ◽  
Farm Animals ◽  
Target Cells ◽  
Heat Stable ◽  
Heat Labile

Enterotoxigenic Escherichia coli (ETEC) strains which produce heat labile and/or heat stable toxins (LT and ST) may cause diarrhea in humans and farm animals. Using PCR primers specific for the LT I and ST II genes, a multiplex PCR system which allows detection of LT I- and ST II-producing ETEC strains was developed. When skim milk was used for a PCR assay, it was found that if target cells in the sample were precultured in MacConkey broth for 8 h prior to PCR as few as 100 cells per ml of the sample could be detected. Without the preculture step, 104 CFU of target cells per 0.2 g of porcine stool specimen were required to generate visible PCR products. The multiplex PCR System can be used for rapid testing of fecal specimens, food and possibly environmental samples for the presence of ETEC strains.

HEAT-STABLE VERSUS HEAT-LABILE VACCINES

The Lancet ◽  
1988 ◽  
Vol 332 (8625) ◽  
pp. 1424-1425 ◽  
Author(s):  
ClaudeP. Muller ◽  
Günther Jung
Keyword(s):  
Heat Stable ◽  
Heat Labile

scholarly journals Does enteropathogenic Escherichia coli produce heat-labile enterotoxin, heat-stable enterotoxins a or b, or cholera toxin A subunits?

1984 ◽  
Vol 46 (2) ◽  
pp. 612-614 ◽  
Author(s):  
S A Long-Krug ◽  
C S Weikel ◽  
K T Tiemens ◽  
E L Hewlett ◽  
M M Levine ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cholera Toxin ◽  
Enteropathogenic Escherichia Coli ◽  
Toxin A ◽  
Heat Stable ◽  
Heat Labile

scholarly journals Plasmid Coding for Drug Resistance and Production of Heat-Labile and Heat-Stable Toxins Harbored by an Escherichia coli Strain of Human Origin

1983 ◽  
Vol 39 (2) ◽  
pp. 970-973 ◽  
Author(s):  
M. Lourdes M. Silva ◽  
Isabel C. A. Scaletsky ◽  
M. Henriqueta L. Reis ◽  
M. Heloiza T. Affonso ◽  
Luiz R. Trabulsi
Keyword(s):  
Escherichia Coli ◽  
Drug Resistance ◽  
Coli Strain ◽  
Human Origin ◽  
Heat Stable ◽  
Heat Labile

Regulation of cell growth by vitreous humour

1985 ◽  
Vol 76 (1) ◽  
pp. 53-65
Author(s):  
G.A. Lutty ◽  
R.J. Mello ◽  
C. Chandler ◽  
C. Fait ◽  
A. Bennett ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Pigment Epithelium ◽  
Chorioallantoic Membrane ◽  
Growth Inhibitor ◽  
Muscle Cells ◽  
In Vitro Assays ◽  
Heat Stable ◽  
Heat Labile

Extracts of normal vitreous have been found to inhibit angiogenesis in two animal models: tumour-induced neovascularization in the rabbit corneal micropocket and retinal extract-induced angiogenesis in the chick chorioallantoic membrane assay. Using in vitro assays, we have found recently that an extract of bovine vitreous, free of hyaluronic acid, inhibits proliferation of cells in the aortic wall, i.e. endothelium and smooth muscle cells, as well as capillary and corneal endothelium. The inhibition is dose-dependent, as determined by either cell count or [3H]thymidine incorporation, and not due to cytotoxicity, as demonstrated with a double-label thymidine assay. The inhibitor is trypsin-sensitive and heat-stable (95 degrees C for 10 min). Conversely, proliferation of pericytes, lens epithelium and fibroblasts (dermal and corneal) was stimulated by the vitreous extract. This mitogenic activity was heat-labile. Growth of pigment epithelium and several tumour cell lines was unaffected. The data demonstrate that normal vitreous contains a heat-stable growth inhibitor specific for endothelium and smooth muscle cells, and a non-specific heat-labile mitogen. The paradoxical effect of this antiangiogenic factor on arterial and capillary contractile cells, smooth muscle and pericytes, suggests a basic difference in the regulation of the two vasculatures. The results suggest that a substance in normal vitreous may be important in controlling neovascularization that results from diabetic and other retinopathies, and could be useful for inhibiting tumour-induced angiogenesis.

Typing of heat-stable and heat-labile antigens of Campylobacter jejuni and Campylobacter coli by coagglutination.

1985 ◽  
Vol 21 (5) ◽  
pp. 702-707 ◽  
Author(s):  
K H Wong ◽  
S K Skelton ◽  
C M Patton ◽  
J C Feeley ◽  
G Morris
Keyword(s):  
Campylobacter Jejuni ◽  
Campylobacter Coli ◽  
Heat Stable ◽  
Heat Labile
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