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Biomedical subjects

D Pappagianis

Publications and source records attributed to D Pappagianis.

At least 91 records · Page 5Linked to original sources

False-positive reactions of cerebrospinal fluid and diluted sera with the coccidioidal latex-agglutination test.

Most samples of cerebrospinal fluid from 49 patients with or without coccidioidomycosis yielded positive agglutination with the Hyland ("CM") latex-particle agglutination test. Furthermore, simple dilution of sera from patients with or without coccidioidomycosis yielded a strong agglutination reaction with the latex particle agglutination test reagent. These reactions were found with three lots of the latex-particle agglutination test reagent. One lot latex particles was found to give agglutination reactions merely by addition of saline solution or water, though a second lot did not. It is advisable, therefore, that the latex-particle agglutination test not be applied to cerebrospinal fluid, and that it be applied cautiously, particularly with diluted sera.

Coccidioidomycosis↗

Treatment of murine coccidioidomycosis with polymyxin B.

An agar dilution method was employed to test the susceptibility of 12 strains of Coccidioides immitis to polymyxin B (PB). After 3 days of incubation, eight strains were markedly inhibited by 5.0 mug of PB per ml and four strains did not grow. PB at 10 mug/ml inhibited the growth of all strains through 20 days of incubation. To determine whether PB has anticoccidioidal activity in vivo, mice in groups of 30 were infected intraperitoneally with a mean lethal dose (LD(50)) or 20 LD(50) of arthrospores of C. immitis ATCC 28868 (Silveira). Treatment by intraperitoneal injection of PB (2.5 mg/kg) was begun 2 or 5 days after challenge. By 40 days after infection, 47 and 7% of the untreated mice challenged with an LD(50), respectively, were alive. Of mice infected with an LD(50) or 20 LD(50) and treated with PB beginning 2 days after the challenge, 90% of each group were alive by day 40. Initiation of PB therapy 5 days after infection permitted survival of 84% of the mice infected with an LD(50); however, only 27% of the mice infected with 20 LD(50) survived by day 40. In this latter group there was evidence that PB prolonged life since 56% of the treated mice were alive by day 15 as compared with 30% of the controls. PB in vivo was fungistatic since the majority of treated mice had C. immitis in the liver, lungs, and spleen.

Animals↗

Effect of amphotericin B and rifampin against Coccidioides immitis in vitro and in vivo.

Amphotericin B, the principal drug used for treating systemic mycoses, possesses undesirable toxic properties. The ability of this antibiotic to potentiate antifungal activity of other compounds suggests that lower doses of amphotericin B could be used in combination with a second drug without loss of therapeutic efficacy. In vitro tests demonstrated that amphotericin B potentiated rifampin against the mycelial growth phase of Coccidioides immitis but not against the spherule-endospore phase. Therapy for murine coccidioidomycosis with a combined amphotericin B-rifampin regimen was not better than treatment with amphotericin B alone; in fact, combined drugs may have been even less effective. This would have clinical significance for therapy of concurrent infections.

Amphotericin B↗

Counterimmunoelectrophoresis in the detection of antibodies against Coccidioides immitis.

In recent years counterimmunoelectrophoresis has been increasingly used in the diagnosis of microbial diseases, and our study was undertaken to evaluate its possible use in the rapid detection of antibodies against Coccidioides immitis. One hundred twelve specimens from 50 patients were studied. The study population comprised the following: Group I, 34 patients with an active coccidioidomycosis infection; Group II, five patients with a positive coccidioidin skin test; Group III, five patients with a negative coccidioidin skin test; and Group IV, six patients with other fungal infections. Counterimmunoelectrophoresis was positive in 93 of 96 specimens in Group I and negative in the other groups. The results obtained by counterimmunoelectrophoresis correlated well with complement fixation and double immunodiffusion and indicate that it is an excellent tool for the diagnosis of patients with coccidioidomycosis.

Acute Disease↗

In vitro hemolysis of autologous erythrocytes caused by immune murine spleen cells and spherules of the fungus Coccidioides immitis.

This communication describes an in vitro system wherein mouse erythrocytes are lysed in the presence of spherules of the fungus Coccidioides immitis and spleen cells from syngeneic mice immunized with a variety of antigens. The antigens include: tobacco mosaic virus in complete Freund's adjuvant (CFA), CFA alone, separate components of CFA, sheep erythrocytes, and allogeneic tumor. Spleen cells from mice sublethally infected with C. immitis are also capable of participating in this response. The lytic phenomenon, which does not require complement, is dependent upon the number of spleen cells per culture, the number of spherules per culture, the time of culture incubation, the amount of antigen injected into the animal and the time after immunization at which spleen cells are recovered. Live spherules or spherules killed with heat, with dimethylsulfoxide, or with formalin were effective participants, together with immune spleen cells, in the lytic reaction.

Animals↗

The present status of vaccination against coccidioidomycosis in man.

Vaccines of killed whole cells of Coccidioides immitis have been injected intramuscularly in 97 human subjects to determine the safety and tolerable dose of vaccine and certain immunologic responses. Seventy-eight individuals received the whole killed spherule preparation; 18 received killed mycelial vaccine. The maximum tolerable dose of spherule vaccine was approximately 5 mg. Systemic effects were slight though in two prior coccidioidin reactors a moderate febrile illness and sbustantial antibody production followed vaccination with killed spherules. The vaccines irregularly induced antibody or delayed hypersensitivity to coccidioidin or spherule antigen. Greater antigenic mass perhaps as a soluble preparation may be needed for consistent immunologic stimulation though the spherule vaccine may be protective despite absence of detectable antibody or sensitivity to coccidioidin.

Adult↗

Coccidioidal arthritis and its treatment -- 1975.

The clinical course of disseminated coccidioidomycosis is highly variable. Neither spontaneous cure nor spontaneous ankylosis has ever been demonstrated in an adult with the disease in one or more disseminated articular foci. Coccidioidomycotic arthritis may fluctuate in activity, and may be compatible with years of limited function and moderate morbidity. Amputation as well as arthrodesis accompanied by adequate excision of diseased tissue are generally reliable methods of treatment of infected joints, but the decision whether or not to "cover" such patients with systemic doses of amphotericin is still difficult, and the roles of synovectomy and topical amphotericin remain to be determined.

Adult↗

Double electroimmunodiffusion: a rapid diagnostic test for canine coccidioidomycosis.

Double electroimmunodiffusion (EID) was adapted for detection of antibodies to Coccidioides immitis. In a limited experiment with canine serums, the test was found to be qualitatively as sensitive as the complement-fixation (CF) test. Advantages of EID over CF are that EID takes only 30 minutes to perform and requires only 10 mul each of antigen and antibody.

Animals↗

Inhibition by lysozyme of growth of the spherule phase of Coccidioides immitis in vitro.

Development of mature endosporulating spherules from an endospore inoculum was markedly inhibited by human or hen egg-white (HEW) lysozyme at 5 mug/ml. Mature spherules formed in medium containing 5 mug per lysozyme per ml (3.3 x 10(-7) M) were approximately 50% smaller than control spherules. In addition, lysozyme induced a large portion of the endospore inoculum to revert to the mycelial growth phase. Increasing lysozyme concentrations to 10 or 20 mug/ml prompted a nearly complete reversion of the inoculum to the mycelial phase. Mature endosporulating spherules removed from growth medium and resuspended in a solution of human or HEW lysozyme at 18 mug/ml in distilled water prompted leakage of four to five times as much of materials absorbing maximally at 260 nm into the supernatant as untreated control spherules during 90 min of incubation. This four- to fivefold increase in nucleotide loss was evident at 4, 25, and 37 C. The permeability of 1-day-old immature spherules and 8-day-old endospores was considerably altered by lysozyme treatment of cells suspended in distilled water. Large amounts of potassium and nucleotides were rapidly lost by each type of cell when treated with 20 mug of lysozyme per ml. After 270 min of exposure to lysozyme, 98% of the immature spherules and 25% of the endospores were nonviable. Lysozyme adsorption by formalin-killed spherules in the presence of varying concentrations of calcium ion and the rapid alteration of permeability seen after lysozyme treatment suggested that the cell membrane was damaged as a result of binding lysozyme.

Animals↗

Experimental induction of anergy to coccidioidin by antigens of Coccidioides immitis.

Failure to react to coccidioidin (anergy) often occurs in patients with disseminated coccidioidomycosis. One possible reason may be desensitization by excessive amounts of antigen. This was studied experimentally by injection of soluble and hyphal antigens of Coccidioides immitis into coccidioidin- and tuberculin-sensitive guinea pigs. Guinea pigs sensitized by injection of killed hyphal cells of C. immitis in complete Freund adjuvant were subsequently injected daily either with soluble coccidioidal antigen administered intraperitoneally or with hyphal antigen administered either subcutaneously or intraperitoneally. Gradual loss of cutaneous reactivity to coccidioidin occurred, but the reactivity to tuberculin remained unimpaired. The rapidity of desensitization was roughly proportional to the dose of antigen with desensitization occurring as early as 6 days after beginning injections. This anergic state was temporary, and reactivity returned several days after discontinuing injection of antigen. Injection of coccidioidal antigen led to production of coccidioidal complement-fixing antibody, but there was no consistent relationship between the antibody titer and state of cutaneous reactivity to coccidioidin. Peritoneal exudate or pulmonary alveolar cells from desensitized animals migrated freely in the presence of coccidioidin but were inhibited in the presence of tuberculin. Heat treatment did not impair the capacity of the soluble or hyphal antigen to induce anergy, thus suggesting that the antigen active in complement fixation was perhaps not involved in desensitization. Polysaccharide obtained by ethanol precipitation of dialyzed coccidioidin failed to induce anergy. Dialysis of the soluble coccidioidal antigen caused the loss of the desensitizing activity. Thus, specific desensitization could be induced by administration of large doses of coccidioidal antigen but dialyzable components appear important in this desensitization.

Animals↗

Effects of lysozyme and chitinase on the spherules of Coccidioides immitis in vitro.

Spherules of Coccidioides immitis strain Silveira produced in vitro were treated with chitinase and lysozyme. The walls of merthiolate-killed mature endosporulating spherules were degraded by chitinase (500 mug/ml) and by lysozyme (100 and 500 mug/ml). Thus, as was visible through the light microscope, the spherule wall was reduced in thickness from 1 to 2 mum to less than 0.5 mum. The degradation was evident also by release of N-acetylglucosamine, three times as much N-acetylglucosamine being released by chitinase in 12 h as was released by lysozyme in 3 days. However, the effect of lysozyme on living mature spherules was in marked contrast to the effect of chitinase in that treatment with lysozyme led to marked reduction in viability. Exposure to lysozyme (500 mug/ml) for 48 h permitted survival of only 0 to 0.2% of spherules. Thinning of the walls was observed only in the larger spherules (25-35 mum) treated with lysozyme. By contrast, chitinase (500 mug/ml) led to complete dissolution of the walls of living mature spherules but the viability of the liberated endospores was unaffected during contact with chitinase for 48 h. Living non-endosporulating immature spherules and free endospores were also rendered nonviable by lysozyme but not by chitinase.

Cell Survival↗

Coccidioidomycosis in Northern California. An outbreak among archeology students near Red Bluff.

An outbreak of coccidioidomycosis occurred among 39 archeology students in the summer of 1972. The students excavated Indian ruins near Red Bluff in Tehama County, California, 20 miles north of the previously recognized northernmost limit of endemicity. At least 17 persons contracted an illness clinically compatible with a diagnosis of coccidioidomycosis. Coccidioidomycosis was documented by skin test conversion as well as by specific serologic reactions. Coccidioides immitis was also isolated from two soil samples taken at the excavation site. In light of its ecological requirements, it is doubtful that C. immitis will be recovered much farther north than Red Bluff. The occupational hazard of coccidioidomycosis to archeologists and others employed in known endemic areas remains a substantial threat to health.

Adolescent↗