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D B Budzko

Publications and source records attributed to D B Budzko.

33 records · Page 2Linked to original sources
PubMed1976

Depletion of complement in vivo and in vitro by extracts of Aspergillus fumigatus.

A new, nontoxic material extracted from Aspergillus fumigatus, is described with complement-depletion capacity both in vivo and in vitro. Extracts of the mycelium of A. fumigatus were found to haemolyse sheep red blood cells, to be lethal for mice and to convert C3 into its faster electrophoretic form when incubated with normal human serum. Conversion did not take place when purified C3 was used, suggesting that serum factors were required in the reaction. Adsorption of the extracts with activated carbon or heating at 100 degrees C for 30 min yielded detoxified materials devoid of both toxic and haemolytic properties but still capable of converting serum C3. In guinea pigs, administration of detoxified extracts was followed by complement depletion lasting not less than 48 h. Heating (100 degrees C for 30 min) extracts which had been previously detoxified by carbon adsorption resulted in a partial loss (40%) of their complement-inhibitory capacity indicating that part of the anticomplementarity of AFE was due to a heat-stable substance.

Animals↗
PubMed1976

Mechanisms of natural resistance to trypanosomal infection. Role of complement in avian resistance to Trypanosoma cruzi infection.

The natural resistance of chickens to Trypanosoma curzi infection and the capacity of their sera to lyse blood (trypomastigote) forms of the parasite in vitro were found to be complement-dependent phenomena. Parasites given intravenously to decomplemented chickens were detectable in their bloodstream for at least 24 h post-infection, whereas in untreated animals they became undetectable after 1 min (and destroyed flagellates were observed). One millilitre of serum had the capacity to lyse as many as 10-30 X 10(6) organisms. The lytic activity of serum in vitro was not impaired in chickens that had been immunosuppressed by four different procedures and was present in the absence of antibodies. In vitro lysis of T. cruzi by either normal or antibody-free chicken sera occurred in the absence of calcium ions but required magnesium ions, indicating that complement was activated via the alternative pathway. Administration of normal chicken serum to mice infected with T. cruzi provoked a marked decrease in their parasitaemias.

Animals↗
PubMed1975

Hemolytic, cytotoxic and complement inactivating properties of extracts of different species of Aspergillus.

Some of the biological properties of saline extracts of the mycelia of several species of the Aspergillus genus, namely, A. fumigatus, A. flavus, A. niger, A. nidulans, A. parasitucus and A. glaucus, were studied. Only the extract prepared from A. fumigatus was found to be hemolytic for sheep red blood cells. In contrast, all the extracts with the only exception of that of A. glaucus, had cytotoxic effects on Vero cells. Both, the hemolytic and cytotoxic constituents of the extracts were removable by adsorption with activated carbon. Heating of the extracts at 100 degrees C for 30 minutes also resulted in detoxification. In vivo studies, performed only with detoxified extracts of A. fumigatus, showed these were capable of depleting complement levels in guinea pigs. Complement inactivation was also found to occur in vitro and was cuased by all the extracts tested. Also triggered by the extracts was the conversion of serum C3 but not of purified C3, indicating that other serum factors are essential in the process. Despite the similarity in this respect with cobra venom factor, differences in activity after heating-negative in cobra venom factor-indicate that the complement inactivating substance/s present in the Aspergillus extracts differ from those of the snake product.

Animals↗
PubMed1975

Effects of complement depletion in experimental chagas disease: immune lysis of virulent blood forms of Trypanosoma cruzi.

In mice infected with virulent blood (trypomastigote) forms of Trypanosoma cruzi, complement depletion with cobra venom factor caused a marked exacerbation of the disease evidenced by significantly increased parasitemia levels and early mortality as compared with those of untreated infected animals. The effect was greater in mice receiving cobra venom factor on day 7 postinfection, i.e., at the time when the parasites had had time to localize and multiply in the tissues and appeared in the circulation in appreciable numbers. The possibility that complement participates in host defense against T. cruzi infection through a mechanism involving immune lysis was explored in vitro. T. cruzi trypomastigotes were found to undergo immune lysis in sera of patients with chronic Chagas' disease, in sera of immunized mice, and in solutions containing both immune mouse gamma globulin and a source of active complement. This phenomenon failed to take place either in the absence of complement or after complement inactivation by heat or utilizing complement inactivators. The lytic capacity of heated sera was restored by the addition of active complement to the system. During the immune lysis of T. cruzi blood forms, complement was activated in human sera via both the classical and the alternate pathways. In mouse sera, activation followed at least the alternate pathway.

Animals↗
PubMed1975

Immunization against experimental Chagas' disease by using culture forms of Trypanosoma cruzi killed with a solution of sodium perchlorate.

Protection against infection with virulent blood (trypomastigote) forms of Trypanosoma cruzi was accomplished in mice by immunization with culture (mainly epimastigote) forms killed by treatment with sodium perchlorate. Sodium chloride, used instead of sodium perchlorate, with all other conditions kept the same, failed to kill all the organisms, indicating that the effects of the perchlorate anion were not simply ionic or osmotic, suggesting that they might be chaotropic. A single dose of the immunogen, without adjuvants, was sufficient to significantly protect against the infection. Protection was achieved by either intraperitoneal, intramuscular, or subcutaneous immunization, though the first two routes appeared to be more effective. After challenge, parasitemias were negative in 25, 29, and 17% of the animals immunized intraperitoneally, intramuscularly, and subcutaneously, respectively.

Animals↗
PubMed1969

Anaphylatoxin release from the third component of human complement by hydroxylamine.

Treatment of highly purified preparations of the third component of complement (C3) with 0.5M hydroxylamine at 20 degrees C for 15 to 30 minutes, followed by acidification, resulted in dissociation of a peptide from the C3 molecule. The isolated fragment (molecular weight, 7600) resembled enzymatically liberated anaphylatoxin (C3a) with respect to size, charge, amino acid composition, and biological activity. Its capacity to contract smooth muscle was inhibitable by antihistamines; it also produced tachyphylaxis and desensitization of the guinea pig ileum to C3a. Thus native C3 probably contains an esterlike bond and hydroxylamine-liberated anaphylatoxin may represent one of the polypeptide chains of the C3 molecule.

Amino Acids↗
PubMedDate not supplied

[Comparison between the bacterial flora airways and of the lung tissue].

In 44 patients tracheotomized and under mechanical ventilation bacteriological studies were carried out, inmediately after death, in bronchial secretions and in a small piece of lung obtained by thoracotomy. The more frequently found bacterium in bronchial secretions or the lung was the Pseudomona aeruginosa (Table 1). In order of decreasing frequency: Klebsiella, Staphylococcus, Proteus, etc. were found in the lung while in bronchial secretions the order was inverse by predominance of Proteus. Total bacteriological coincidence was found in 14 cases while it was partial in 8 more patients where another bacterium was added in bronchial secretions. Bacteria were different in 6 cases (Table 2) in 4 of them: staphylococcus was obtained in the lung while Pseudomonae, Proteus and Klebsiellae were present in bronchial secretions (Table 3). In 16 cases cultures of the piece of lung taken were negative. Not taking into account these last ones, it is possible to conclude that from the therapeutic stand point culture of bronchial secretions was useful in antibiotic selection in 22 out of 28 cases.

Bacteria↗