Observations on the Toxic Fractions of Scarlatinal Streptococci

1. Among a series of strains of haemolytic streptococci from thirty-five cases of scarlatina in the first week of illness, fourteen were found to correspond with one or other of Griffith's serological types I, II, III and IV.2. Of these fourteen strains, twelve were selected for further examination and found to yield a true heat-labile exotoxin completely inactivated by heating for 30 min. at 100° C.3. The concentration of exotoxin in 0·5 per cent, glucose broth cultures was at a maximum after 96 hours' incubation, and thereafter on further incubation progressively diminished.4. No qualitative difference could be detected among the exotoxins from the different strains, the test criterion being the dermal reaction in Dick-positive persons.5. Cultures of organisms of the same or different serological type isolated from the same source and thereafter similarly treated yielded approximately equivalent amounts of exotoxin.6. Broth culture filtrates also contained an acid-insoluble toxic fraction, the concentration of which increased with the age of culture and which appeared to be identical with a similar acid-insoluble fraction derived from an alkaline extract of washed bacterial bodies.7. This acid-insoluble fraction was extremely heat-resistant, 3 hours' boiling at 100° C. being required for inactivation. In this respect the acid-insoluble fraction corresponded to the bacterial endotoxins.8. The acid-insoluble fractions from cultures of the same serological type produced equivalent skin reactions in susceptible persons.9. The acid-insoluble fractions from cultures of different serological types differed qualitatively as determined by skin reactions.10. The reaction to crude filtrate was found to be the sum of the reactions to the exotoxin fraction and to the acid-insoluble fraction present in the filtrate.

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Observations on the antigenicity and serological relationships of stocks ofTrypanosoma congolensefrom East and West Africa

Parasitology ◽

10.1017/s0031182000053749 ◽

1979 ◽

Vol 79 (3) ◽

pp. 337-347 ◽

Cited By ~ 10

Author(s):

A. G. Luckins ◽

A. R. Gray

Keyword(s):

West Africa ◽

Trypanosoma Congolense ◽

Glossina Morsitans ◽

Skin Reactions ◽

Local Skin ◽

Cross Reactions ◽

Different Strains ◽

Antigenic Relationships ◽

Antigenic Heterogeneity ◽

Different Parts

SUMMARYAntigenic relationships of 4 stocks ofTrypanosoma congolensefrom different parts of Africa were examined by immunofluorescence (IFAT) and neutralization tests. Antisera to each stock were obtained from rabbits infected with trypanosomes transmitted byGlossina morsitans. Trypanosomes for use as antigens were obtained from local skin reactions developing on rabbits infected with 2 of the stocks. Using the IFAT and antisera at end-point dilutions approximately 40% of the trypanosomes fluoresced strongly and a further 30% less intensely with homologous antisera, indicating antigenic heterogeneity among the trypanosomes developing in the skin. Using antisera at low dilutions some samples gave cross-reactions with trypanosomes of heterologous stocks, but at higher dilutions there were no cross-reactions with either of the antigens. The lack of cross-reactions at high antiserum dilutions was interpreted as indicating antigenic differences between the 4 trypanosome stocks. Using neutralization tests only homologous antisera reduced the infectivity of trypanosome suspensions. Overall, these observations indicated that there were at least 3 different strains ofT. congolenseamong the 4 stocks examined.

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Photosynthetic and light-independent carbon fixation in Macrocystis, Nereocystis, and some selected Pacific Laminariales

Canadian Journal of Botany ◽

10.1139/b79-110 ◽

1979 ◽

Vol 57 (8) ◽

pp. 890-897 ◽

Cited By ~ 18

Author(s):

J. Willenbrink ◽

B. P. Kremer ◽

K. Schmitz ◽

L. M. Srivastava

Keyword(s):

Phosphoenolpyruvate Carboxykinase ◽

Carbon Fixation ◽

Soluble Fraction ◽

Qualitative Difference ◽

Calvin Cycle ◽

Insoluble Fraction ◽

Light Saturation ◽

Short Term ◽

Macrocystis Integrifolia ◽

C Assimilation

The large kelp Macrocystis integrifolia and Nereocystis luetkeana off the coast of British Columbia have light saturation points at about 200 foot candles (1 foot candle = 10.76391 lx); however, photosynthetic rates remain unimpeded through mugh higher light intensities, up to 7000 foot candles. Short-term labelling experiments indicate that the Calvin cycle is operational in these plants, but, in addition, and particularly in the young growing parts, relatively high activities of phosphoenolpyruvate carboxykinase (PEP-CK)and correspondingly high rates of 14C fixation in the dark are observed. In older, mature parts, the activity of PEP-CK as well as the ability for light-independent 14C assimilation are lower. These observations are supported by data from a variety of other Pacific Laminariales. Pulse–chase experiments in the light and in the dark reveal characteristic differences between young and mature parts of the fronds: apart from qualitative difference in the soluble fraction of assimilates, the young parts show a significantly large proportion of radiocarbon confined to the ethanol-insoluble fraction.

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Lateral asymmetry of paw usage: phenotypic survey of constitutive and experience-conditioned paw-usage behaviours among common strains of the mouse

Genome ◽

10.1139/g01-045 ◽

2001 ◽

Vol 44 (4) ◽

pp. 539-548 ◽

Cited By ~ 4

Author(s):

Fred G Biddle ◽

Brenda A Eales

Keyword(s):

Quantitative Difference ◽

Qualitative Difference ◽

Test Chamber ◽

Test Sequence ◽

Lateral Asymmetry ◽

Left And Right ◽

The Difference ◽

Different Strains ◽

Conditioned Behaviour ◽

The Right

Left-right direction of paw usage in the mouse is defined by the right-paw entry (RPE) score, which is the number of reaches with the right paw to retrieve food from a small food tube in a total of 50 right- and left-paw reaches. Two qualitatively different paw-usage behaviours can be identified by the difference in the RPE scores from naive mice in left- or right-biased test chambers and their retest, 1 week later, in the opposite-biased test chamber. In mice with constitutive paw usage, the RPE score may respond to the direction of a biased test chamber, but it returns to the value that is expected for naive mice in the opposite-biased test chamber. In mice with experience-conditioned paw usage, the RPE score responds to the direction of a biased test chamber and does not return to its expected value in the opposite-biased test chamber. In this report, we document the alternate paw usage behaviours in an extended phenotypic survey of different strains that will be useful for its genetic analysis. We also validate an alternate biometrical method to identify constitutive and experience-conditioned paw usage that is based on the mean average RPE score from the biased test and opposite-biased retest of individual mice. This alternate biometrical method demonstrated that, in some strains with experience-conditioned paw usage, there may be asymmetry or an interaction between genotype and the direction of the test sequence. In addition, the strain survey demonstrated that the qualitative difference between constitutive and experience-conditioned paw usage is independent of the well-known quantitative difference in the degree of lateralization of preferred-paw usage.Key words: mouse, lateral asymmetry of paw usage, left and right handedness, behavioural genetics, constitutive behaviour, experience-conditioned behaviour.

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Matrix Metalloproteinases as Markers of Acute Inflammation Process in the Pulmonary Tuberculosis

Data ◽

10.3390/data4040137 ◽

2019 ◽

Vol 4 (4) ◽

pp. 137 ◽

Cited By ~ 2

Author(s):

Anastasia Lavrova ◽

Diljara Esmedljaeva ◽

Vitaly Belik ◽

Eugene Postnikov

Keyword(s):

Pulmonary Tuberculosis ◽

Probability Distributions ◽

Qualitative Difference ◽

Small Samples ◽

Host Immune System ◽

Clinical Prognosis ◽

Surgical Interventions ◽

The Difference ◽

Different Strains ◽

Drug Resistant Strains

The main factors of pathogenesis in the pulmonary tuberculosis are not only the bacterial virulence and sensitivity of the host immune system to the pathogen, but also the degree of destruction of the lung tissue. Such destruction processes lead to the development of caverns, in most cases requiring surgical interventions besides the drug therapy. Identification of special biochemical markers allowing to assess the necessity of surgery or therapy prolongation remains a challenge. We consider promising markers—metalloproteinases—analyzing the data obtained from patients with pulmonary tuberculosis infected by different strains of Mycobacterium tuberculosis. We argue that the presence of drug-resistant strains in lungs leading to complicated clinical prognosis could be justified not only by the difference in medians of biomarkers concentration (as determined by the Mann–Whitney test for small samples), but also by the qualitative difference in their probability distributions (as detected by the Kolmogorov–Smirnov test). Our results and the provided raw data could be used for further development of precise biochemical data-based diagnostic and prognostic tools for pulmonary tuberculosis.

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IDENTITY OF THE TOXINS OF DIFFERENT STRAINS OF BACILLUS WELCHII AND FACTORS INFLUENCING THEIR PRODUCTION IN VITRO

Journal of Experimental Medicine ◽

10.1084/jem.26.6.867 ◽

1917 ◽

Vol 26 (6) ◽

pp. 867-883 ◽

Cited By ~ 3

Author(s):

Carroll G. Bull ◽

Ida W. Pritchett

Keyword(s):

Virulent Strain ◽

High Titer ◽

Lethal Dose ◽

Toxin Production ◽

Single Strain ◽

Cent Glucose ◽

Dose Ranging ◽

Different Strains ◽

Different Sources

Twenty-two additional strains of Bacillus welchii have been collected from widely different sources and tested with regard to toxin production. Each strain produces a toxin which, on animal inoculation, gives rise to lesions comparable in every respect to those produced by the toxins previously reported on, and each toxin was neutralized by an immune (antitoxic) serum produced with one of the former toxins. The toxins obtained from the several individual strains varied in potency, the lethal dose ranging from 0.3 to 3 cc. Experiments have been made to determine the influence of fresh muscle and glucose on toxin production and the relation of acidity to toxicity in the filtrates. It has been found that the addition of fresh muscle to the medium increases the potency of the toxin fivefold. Autoclaved muscle is without effect. Beef infusion broth containing 0.2 to 1 per cent glucose gives a more potent product than sugar-free broth, while when higher percentages are employed the toxin production is lowered. There is no direct relation between acidity and toxicity, the most acid products manifesting little or no toxic action. In every medium used for culture the potency of the filtrates rapidly diminished after 24 hours' incubation, while the acidity increased or remained constant. The exception to this rule has been pointed out. The most active toxin is obtained by growing a virulent strain of the bacilli in a 0.2 or 0.3 per cent glucose broth to which fragments of fresh muscle have been added, and collecting the filtrate after from 18 to 24 hours' incubation. A review of the literature on the pathogenic effects and toxic products of Bacillus welchii and on the results of immunization of animals with the bacilli or toxic products does not indicate that the exotoxic nature of Bacillus welchii had been previously determined or an antitoxic serum in the true sense produced. The antitoxin for Bacillus welchii toxin can apparently be prepared from a single strain of the organism which yields under the conditions described a high titer of toxin, and this antitoxin can be employed to combat infection with or prevent infection by any strain whatever of the bacillus.

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PATHOGENESIS OF EXPERIMENTAL SHOCK

Journal of Experimental Medicine ◽

10.1084/jem.114.2.195 ◽

1961 ◽

Vol 114 (2) ◽

pp. 195-204 ◽

Cited By ~ 7

Author(s):

Arnold L. Nagler ◽

Benjamin W. Zweifach

Keyword(s):

Hemorrhagic Shock ◽

Passive Transfer ◽

Skin Reactions ◽

Positive Skin ◽

E Coli ◽

Bacterial Endotoxins ◽

Experimental Shock ◽

Test Reactions ◽

Shwartzman Reaction ◽

Shwartzman Phenomenon

A series of biological test reactions was used in order to establish the presence of bacterial endotoxins in the blood of rabbits during the progression of hemorrhagic shock. 1. When the shocked animal was used as the test object, it was not possible to induce either the generalized Shwartzman reaction or the dermal Shwartzman phenomenon with exogenous endotoxin (S. enteritidis or E. coli) as one of the two provocative factors. 2. Epinephrine instilled into the skin of rabbits either before, during, or after an episode of hemorrhagic shock did not result in the hemorrhagic skin reaction which occurs in the presence of as little as 1 µg of endotoxin intravenously. 3. Passive transfer from a donor in the irreversible phase of shock of 20 to 25 ml of blood into a primed recipient (B.P. at 40 mm Hg for 1 hour) was uniformly lethal. 4. Similar amounts of blood from such shocked donor failed upon intravenous injection to elicit a protective hemorrhagic reaction in skin sites which were infiltrated with 100 µg of epinephrine. In the same animals 1 µg of endotoxin added to the blood samples caused a positive dermal response. 5. Blood was taken from rabbits which had been pretreated with S. enteritidis endotoxin and then subjected to hemorrhagic shock (35 mm Hg for 2 hours). Such samples upon passive transfer produced positive skin reactions in epinephrine sites but were not lethal to the primed test recipient used in these studies. It is concluded that the contribution of bacterial endotoxemia to the genesis of hemorrhagic shock remains to be determined.

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Seti Figure of Merit

International Astronomical Union Colloquium ◽

10.1017/s0252921100015293 ◽

1997 ◽

Vol 161 ◽

pp. 711-717 ◽

Cited By ~ 1

Author(s):

John W. Dreher ◽

D. Kent Cullers

Keyword(s):

Figure Of Merit ◽

Qualitative Difference ◽

Current Generation ◽

Detection Range ◽

Sky Surveys ◽

Independent Observations ◽

Good For

AbstractWe develop a figure of merit for SETI observations which is anexplicitfunction of the EIRP of the transmitters, which allows us to treat sky surveys and targeted searches on the same footing. For each EIRP, we calculate the product of terms measuring the number of stars within detection range, the range of frequencies searched, and the number of independent observations for each star. For a given set of SETI observations, the result is a graph of merit versus transmitter EIRP. We apply this technique to several completed and ongoing SETI programs. The results provide a quantitative confirmation of the expected qualitative difference between sky surveys and targeted searches: the Project Phoenix targeted search is good for finding transmitters in the 109to 1014W range, while the sky surveys do their best at higher powers. Current generation optical SETI is not yet competitive with microwave SETI.

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Ultrastructural Changes of the Symbiotic Chlorella-Like Alga Isolated from Hydra Viridis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100054212 ◽

1982 ◽

Vol 40 ◽

pp. 320-321

Author(s):

K.W. Lee ◽

R.H. Meints ◽

D. Kuczmarski ◽

J.L. Van Etten

Keyword(s):

Time Course ◽

Reciprocal Cross ◽

Ultrastructural Level ◽

Ultrastructural Changes ◽

Symbiotic Relationship ◽

Cell Recognition ◽

Green Hydra ◽

Different Strains ◽

Hydra Viridis

The physiological, biochemical, and ultrastructural aspects of the symbiotic relationship between the Chlorella-like algae and the hydra have been intensively investigated. Reciprocal cross-transfer of the Chlorellalike algae between different strains of green hydra provide a system for the study of cell recognition. However, our attempts to culture the algae free of the host hydra of the Florida strain, Hydra viridis, have been consistently unsuccessful. We were, therefore, prompted to examine the isolated algae at the ultrastructural level on a time course.

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