Biomedical subjects

D Pappagianis

Publications and source records attributed to D Pappagianis.

At least 55 records · Page 3Linked to original sources

PubMed1992

Vasculitic and encephalitic complications associated with Coccidioides immitis infection of the central nervous system in humans: report of 10 cases and review.

Six cases of apparent and four cases of histopathologically confirmed vasculitis of the central nervous system (CNS), including one case of histopathologically documented vasculitis with encephalitis associated with coccidioidal meningitis (CM), are presented. Vasculitic complications included changes in mental status as well as stroke-like findings of aphasia, hemianopsia, and hemiparesis. Seven patients died. Vasculitic complications were unanticipated and often abrupt in onset, and delayed therapeutic intervention was characteristic. The diagnosis of vasculitis/encephalitis due to Coccidioides immitis infection must be based on clinical judgment, since serum antibody titers, cerebrospinal fluid findings, and initial radiological studies are not always helpful. Institution of both intravenous and intracisternal administration of amphotericin B and possibly concomitant intravenous administration of dexamethasone may be warranted in situations in which the association of C. immitis with CNS vasculitis or encephalitis appears likely before serologic or cultural confirmation of C. immitis infection involving the CNS is available.

Adult↗

PubMed1992

The coccidioidal complement fixation and immunodiffusion-complement fixation antigen is a chitinase.

Culture filtrates and autolysates of Coccidioides immitis have provided suitable crude antigens for the serodiagnosis and prognosis of coccidioidomycosis. One of these, a heat-labile antigen which participates in the immunodiffusion reaction corresponding to the complement fixation reaction (IDCF), has been characterized as a 110-kDa native protein that, when subjected to reducing conditions and heat, yields a 48-kDa component. The present report provides serologic and biochemical evidence that this antigen is a chitinase. This chitinase, isolated from 48-h culture filtrate of the spherule-endospore-phase C. immitis by affinity adsorption to chitin, formed a line of identity with the IDCF reference antigen and participated in the complement fixation reaction with human serum. It lost its enzymatic as well as antigenic activity when heated, but when not heated it retained its enzymatic activity even when precipitated with coccidiodal antibody present in human serum. This chitinase represents a significant serodiagnostic substance and may be important in the morphogenesis of C. immitis.

Antigens, Fungal↗

PubMed1990

Coccidioidomycosis during human immunodeficiency virus infection. A review of 77 patients.

Through a retrospective review, we identified 77 previously unreported cases of coccidioidomycosis during HIV infection. Patients were classified into 1 of 6 categories based on their primary clinical presentation: 20 had focal pulmonary disease (Group 1), 31 had diffuse pulmonary disease (Group 2), 4 had cutaneous coccidioidomycosis (Group 3), 9 had meningitis (Group 4), 7 had extrathoracic lymph node or liver involvement (Group 5), and 6 has positive coccidioidal serology without a clinical focus of infection (Group 6). Coccidioidal serologies were positive on initial testing in 83% of the patients in whom such serologic testing was performed. Sera from 39% of patients were positive for TP antibodies while 74% had CF antibodies. Eleven of 12 seronegative patients had pulmonary disease (Group 1 or 2). Serologic results of other patients sent to a single reference laboratory were similar, with 26% positive for immunodiffusion TP antibodies and 79% positive for immunodiffusion CF antibodies. For the 77 patients in this study, the CD4-lymphocyte count was below 0.250 X 10(9) cells/L in 46 of the 55 patients who had this test performed, and a low CD4 count was significantly associated with mortality (p less than 0.01). At the time of follow-up, 32 of the 77 patients (42%) had died. There were significantly more deaths in those with diffuse pulmonary disease (Group 2) than in other groups (p less than 0.001). Amphotericin B, ketoconazole, fluconazole, and itraconazole were all used as antifungal therapies. Outcome could not be related to the therapy used. Of note, 3 patients developed coccidioidomycosis while receiving ketoconazole for other conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

Evaluation of nikkomycins X and Z in murine models of coccidioidomycosis, histoplasmosis, and blastomycosis.

Nikkomycins X and Z, competitive inhibitors of fungal chitin synthase, were evaluated as therapeutic agents in vitro and in mouse models of coccidioidomycosis, histoplasmosis, and blastomycosis. In vitro, the nikkomycins were found to be most effective against the highly chitinous, dimorphic fungi Coccidioides immitis and Blastomyces dermatitidis, were less effective against yeasts, and were virtually without effect on the filamentous fungus Aspergillus fumigatus. Additionally, by transmission electron microscopy, nikkomycin Z was highly disruptive to the cell wall and internal structure of the spherule-endospore phase of C. immitis in vitro. In vivo, nikkomycin Z was more effective than nikkomycin X, was also found to be superior on a milligram per milligram basis to the majority of azoles tested in the models of coccidioidomycosis and blastomycosis, and was moderately effective in histoplasmosis. A study of the pharmacokinetics in mice showed that nikkomycin Z was rapidly eliminated after intravenous infusion but that absorption after oral administration was sufficiently slow to allow inhibitory levels to persist for more than 2 h. Results of limited toxicology tests suggest that nikkomycin Z was well tolerated at the dosages employed.

Administration, Oral↗

PubMed1990

Therapeutic effect of the triazole Bay R 3783 in mouse models of coccidioidomycosis, blastomycosis, and histoplasmosis.

A new triazole, Bay R 3783, was compared with ketoconazole, itraconazole, and fluconazole, which were given via the alimentary tract at three dosages, and amphotericin B, which was given at 1 mg/kg intraperitoneally, in murine models of the systemic mycoses coccidioidomycosis, histoplasmosis, and blastomycosis. In a pulmonary coccidioidomycosis model, Bay R 3783, fluconazole, and itraconazole were essentially equally efficacious and more active than ketoconazole in protecting mice against death; but they were inferior to amphotericin B. In a short-term organ load experiment, Bay R 3783 and amphotericin B were equally effective and were more effective than the other drugs in reducing the amount of Coccidioides immitis in the lungs. Against meningocerebral coccidioidomycosis, Bay R 3783, itraconazole, and fluconazole at 25 mg/kg and amphotericin B prevented death only during therapy, with mortalities ensuing shortly thereafter. In mice with systemic histoplasmosis, Bay R 3783 and itraconazole at 25 mg/kg and amphotericin B prevented death in all mice through a 44-day observation period. Clearance of Histoplasma capsulatum from organs was similar in mice treated with Bay R 3783 and itraconazole; this clearance was greater than that in mice treated with ketoconazole and fluconazole but less than that in mice treated with amphotericin B. In mice with systemic blastomycosis, Bay R 3783 at 25 mg/kg yielded 90% survivors at 60 days, which was greater than that achieved with amphotericin B (60%) or itraconazole (30%). Clearance of Blastomyces dermatitidis from the lungs was greatest with Bay R 3783, followed by that with amphotericin B, itraconazole, fluconazole, and ketoconazole, in that order. Therefore, Bay R 3783 showed effectiveness comparable to or exceeding those of itraconazole and fluconazole and exceeding that of ketoconazole against these systemic mycoses in mice.

Animals↗

PubMed1990

Serology of coccidioidomycosis.

Serologic tests have assisted in the diagnosis and prognosis of coccidioidomycosis for a half-century. The causative agent, Coccidioides immitis, is a dimorphic fungus existing in a hyphal form with arthroconidia in nature and in the usual culture. The arthroconidia represent the inhaled infective forms which in vivo and under special laboratory conditions form spherules which endosporulate. The culture filtrate/autolysate (coccidioidin) from the hyphal phase has provided antigens of suitable reliability for currently used serologic tests. These tests are primarily to determine the two major antibody responses: the early immunoglobulin M (IgM) response is useful in the diagnosis of acute primary coccidioidomycosis. Later, IgG is produced and usually outlasts the IgM, persisting in chronic coccidioidomycosis. The IgM is detectable by tube precipitin, a corresponding immunodiffusion, or latex particle agglutination tests. The pertinent antigen(s) is heat stable and pronase resistant and appears to be largely carbohydrate, mainly mannose with some 3-O-methyl mannose. The IgG detectable in the serum and other body fluids by complement fixation and a corresponding immuno-diffusion is useful in diagnosis, and its quantitation provides an indicator of progression of disease (increasing titer) or regression (decreasing titer). The pertinent antigen appears to be a heat-labile, pronase-sensitive protein which in an unreduced form has a molecular weight of 110,000. A third very useful serologic procedure is the exoantigen test for identification of putative cultures of C. immitis.

Animals↗

PubMed1990

Purification and amino-terminal sequence analysis of the complement-fixing and precipitin antigens from Coccidioides immitis.

Two proteins (21 and 48 kilodaltons) purified from endospore-spherule culture filtrates of Coccidioides immitis are identified as precipitin and complement-fixing antigens, respectively. To allow specific structural comparison to antigens identified by other investigators and as a first step to eventual serodiagnostic antigen production by recombinant DNA technology, amino-terminal amino acid sequences were determined for these antigens.

Amino Acid Sequence↗

PubMed1989

Immunoaffinity isolation and partial characterization of the Coccidioides immitis antigen detected by the tube precipitin and immunodiffusion-tube precipitin tests.

The antigen participating in the tube precipitin (TP) serologic test for coccidioidomycosis was isolated from mycelial-phase antigen (coccidioidin) by immunoaffinity and characterized by various analytical procedures. This was accomplished by first preparing the antigen-antibody precipitate by using antigen and human serum positive for TP (immunoglobulin M) antibody and then liberating the antigen by digestion with pronase. This protease destroyed the antibody and left the antigen intact as indicated by immunodiffusion-TP. The coccidioidal antigen was isolated from the proteolytic digest by using size exclusion chromatography. DEAE chromatography of this antigen yielded two fractions with immunodiffusion-TP reactivity which had average molecular sizes of 225 and 140 kilodaltons, respectively. The presence of carbohydrate and amino acids indicated that the antigen(s) is a glycopeptide. Compositional analysis showed that one fraction contained 3-O-methylmannose, mannose, and glucose in a ratio of 8:1.2:1, whereas the second fraction contained 3-O-methylmannose, mannose, glucose, and galactose in a ratio of 1:1:1:1. The amino acids glycine, alanine, serine, threonine, aspartic acid plus asparagine, and glutamic acid plus glutamine constituted 60 to 70% of the amino acids in both glycopeptides. Neither antigen could be detected entering the gel in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Lectin affinity provided evidence of a high-mannose asparagine-linked glycopeptide in the first peak and an asparagine-linked glycopeptide with a biantennary complex-type structure in the second peak.

Amino Acids↗

PubMed1988

Epidemiology of coccidioidomycosis.

Coccidioides immitis naturally occurs in the soil and air of certain areas of the New World. These are generally arid to semiarid areas that have relatively modest rainfall, mild winters, and prolonged hot seasons. Coccidioidomycosis is usually a disease of human and nonhuman residents of these areas; but visitors may develop the disease after entering these areas and returning home long distances from the endemic areas. Inhalation (rarely percutaneous introduction) of arthroconidia of C. immitis leads to usually benign but occasionally severe and even fatal infection. Recovery from or asymptomatic infection leads to resistance to reinfection. Exposure to soil (dust) means that certain occupations are more likely to be exposed to C. immitis. Persistence of the organism in the soil means that infections will be encountered in the future, particularly as long as susceptible newcomers continue to enter endemic areas. Those who have been infected and recovered generally will be resistant to later infection, although exacerbation may occur as a result of superimposed immunosuppression.

Age Factors↗

PubMed1988

Regulation of immune responses by T suppressor cells and by serum in chronic paracoccidioidomycosis.

Regulation of cellular responses was studied during the course of chronic murine disseminated paracoccidioidomycosis. Regulation of peripheral blood lymphocyte (PBL) proliferative responses to concanavalin A (Con A) was studied in vitro by mixing PBL from infected and noninfected mice. PBL from mice infected for 18 weeks had depressed responses to Con A and they depressed the Con A responses of PBL from noninfected mice by 95% when they were mixed in a 1:1 ratio. After treatment of PBL from infected mice with anti-Lyt-2.2 antibody plus complement, the responses to Con A were increased to normal values. The percentage of T-cell subpopulations in PBL from infected mice did not differ significantly from those of normal mice. Immunoregulation of delayed-type hypersensitivity (DTH) responses to antigen by serum from infected animals was studied in mice 1 week after intranasal (i.n.) infection, a time when DTH responses were maximal. DTH responses to antigen 7 days after i.n. infection (10(7) CFU Paracoccidioides brasiliensis) were significantly reduced when 0.5 ml of immune mouse serum (ELISA antibody titer to P. brasiliensis antigens 1:10,240) was given i.v. 1 day before infection (P less than 0.01) or 1 day before skin testing (P less than 0.001). Normal mouse serum did not have this effect. The results indicate that progression of chronic disseminated paracoccidioidomycosis was associated with the development of T-cell suppressor activity for Con A responses of PBL, and that DTH responses to antigen were depressed by the administration of serum with specific high titer antibodies.

Animals↗

PubMed1988

Impairment of cellular but not humoral immune responses in chronic pulmonary and disseminated paracoccidioidomycosis in mice.

Humoral and cellular immune responses were measured during the progression of chronic pulmonary and disseminated paracoccidioidomycosis in mice. The chronic disease was established by pulmonary infection of mice with different doses of the yeast form of Paracoccidioides brasiliensis isolate GAP. Levels of antibodies to P. brasiliensis, detected in serum by immunodiffusion and enzyme-linked immunosorbent assay, directly correlated with the size of the infectious challenge. Significant delayed-type hypersensitivity (DTH) responses to antigen were largely restricted to week 1 after pulmonary infection with intranasally administered high doses (5.0 x 10(6) or 1.1 x 10(7) CFU per inoculum). In vitro lymphoproliferative responses of peripheral blood lymphocytes (PBL) to P. brasiliensis antigens were significant only at 2 weeks after infection with intranasally administered 1.1 x 10(7) CFU. Responses of PBL to concanavalin A were depressed (50% of control response) as early as 8 weeks and reached a nadir at 10 to 18 weeks after infection. Infected mice made antibodies to sheep erythrocytes (SRBC) (10(9) intravenously [i.v.]) normally at all times tested after infection. In contrast, infected mice sensitized to SRBC (10(6) i.v.) had significantly depressed DTH responses to SRBC at 9 and 20 weeks postinfection compared with noninfected mice. These results indicated that in this model, normal humoral responses developed to homologous and heterologous antigens. In contrast, the T cellular immune responses were depressed with progression and chronicity of the disease. Thus, this model closely mimics the immunological findings in human paracoccidioidomycosis.

Animals↗

PubMed1988

Characterization of a soluble protein of Coccidiodes immitis with activity as an immunodiffusion-complement fixation antigen.

A 48-kilodalton (kDa) electrophoretically distinct antigen from Coccidioides immitis mycelial- and spherule-endospore-phase filtrates was previously associated by immunoblotting with the immunodiffusion band that corresponds to complement-fixing activity (ID-CF). To characterize this antigen and its precursor, both mycelial- and spherule-endospore-phase filtrates were fractionated by size exclusion chromatography, lectin affinity chromatography, and nondenaturing electrophoresis. By size exclusion chromatography, most of the protein and carbohydrate of the crude filtrates eluted in a peak of average molecular size less than 30 kDa, although other components were detected. ID-CF activity was associated with the component at a relative mobility of 110 kDa. Fractions containing the ID band that corresponded to tube precipitin activity occurred from 200 to 40 kDa. The appearance of the 48-kDa band in denaturing sodium dodecyl sulfate-polyacrylamide gel electrophoresis (PAGE) specifically coincided with the fractions containing ID-CF activity. Nondenaturing PAGE of filtrates showed silver-stainable and immunoblot-reactive bands in the region of 110 kDa. Prior treatment with pronase destroyed this electrophoretically separable antigen, whereas periodate had no effect. Trypsin did not affect the 110-kDa band in unheated or unreduced antigen. Mycelial filtrates were chromatographed on lentil lectin or concanavalin A-Sepharose 4B to deplete them of glucose- or mannose-containing carbohydrate. The effluent fraction contained ID-CF activity and, upon denaturing electrophoresis, the 48-kDa antigen. The 110-kDa protein represents the ID-CF antigen which is heat labile and denatured to a 48-kDa band by sodium dodecyl sulfate-PAGE.

Antigens, Fungal↗

PubMed1988

Microtiter method for MIC testing with spherule-endospore-phase Coccidioides immitis.

A method was developed for susceptibility testing with spherule-endospore-phase Coccidioides immitis by using a microtiter format. Isolated endospores were used to inoculate wells containing modified Converse medium with various concentrations of azole or nikkomycin antifungal substances which then were sealed with an acetate film. The plate was incubated at 37 degrees C with shaking for 96 h, after which the control wells had visible turbidity and endpoints were discernible. Microscopic examination revealed that both control and treatment wells maintained cells predominantly in the spherule-endospore phase of growth.

Antifungal Agents↗

PubMed1987

Chronic pulmonary and disseminated paracoccidioidomycosis in mice: quantitation of progression and chronicity.

An animal model of chronic paracoccidioidomycosis was established in male adult BALB/cByJIMR mice by intranasal instillation of different doses of yeast form Paracoccidioides brasiliensis. The inoculum was standardized in terms of virulence, age of the culture, percentage of multicellular fungal units containing 1-3 cells, and viability. Progression and chronicity of the infection was measured by quantitative counts of colony forming units (CFU) of P. brasiliensis from infected lungs, spleens, and livers in a newly developed culture medium. The body weight of the mice and the organ weights were also used to monitor the disease process. Infection with several challenge sizes progressed in the lungs until a maximum of 10(7)-10(8) CFU per lung was reached; in general, the higher the inoculum, the sooner this maximum was reached. In mice infected with 2.5 X 10(6) CFU the maximum was reached at 8 weeks, whereas in mice infected with 3 X 10(4) CFU the maximum was reached 14 weeks after infection. Dissemination of the disease progressed until there were 10(6)-10(7) CFU per spleen or liver. The higher the infective dose, the shorter the time required to reach a maximum stable population of yeasts in spleen and liver (12 weeks with inoculum of 2.5 X 10(6) CFU, 18-26 weeks with inoculum of 7.0 X 10(3) CFU). The body weight of mice tended to diminish with time after infection compared to uninfected controls. In contrast, the weight of lung and spleen increased with time after infection. This model of chronic paracoccidioidomycosis permits evaluation of progression of the disease process and of the multiplication of the yeast in organs.

Animals↗

PubMed1987

Proteinase production by the parasitic cycle of the pathogenic fungus Coccidioides immitis.

Coccidioides immitis is the causative agent of coccidioidomycosis (valley fever), a potentially disseminated fungal disease. We hypothesized that proteinases are expressed by the parasitic life cycle of C. immitis and that they might play an important role in the pathogenesis of coccidioidomycosis by facilitating spherule rupture, endospore dissemination, and tissue invasion and destruction. Filtrate from cultures of the parasitic life cycle of C. immitis was therefore assayed for proteolytic activity at neutral pH. The filtrate degraded 68% of a radiolabeled model of an elastin-rich extracellular matrix. The principal activity was against elastin and glycoprotein in the matrix. Degradation of purified elastin by filtrate was 222 micrograms/h per mg of filtrate protein at 37 degrees C. Denatured type I collagen (Azocoll) degradation was 13.5 mg/h per mg of filtrate protein at 37 degrees C. Proteinase activity peaked at 60 h of culture, correlating with release of endospores from mature spherules in the in vitro culture system. Elastase activity was attributed to a serine proteinase which exhibited an active-site preference for phenylalanine at the P1 site. The subunit molecular mass of the elastase determined by [3H]diisopropylfluorophosphate labeling was approximately 25 kilodaltons. Inhibition of the azocollytic activity of crude filtrate by 2 mM 1,10-phenanthroline and 10 mM EDTA, and stimulation by 2 mM CaCl2, suggested that a metalloproteinase was also present. Gelatin substrate gel electrophoresis with and without inhibitors confirmed that two proteinases were expressed, and they were separated by fast protein liquid chromatography.

Coccidioides↗

PubMed1986

Disseminated coccidioidomycosis in a patient with the acquired immune deficiency syndrome.

Disseminated coccidioidomycosis is a recognized but infrequent accompaniment of the acquired immune deficiency syndrome (AIDS). A patient with AIDS, Pneumocystis carinii pneumonia, and disseminated coccidioidomycosis occurring outside of an endemic area is described. Fungal infection presented atypically with progressive thoracic adenopathy and the development of cold soft tissue abscesses. As is often the case with AIDS, serologic testing proved to be unreliable and tissue biopsy the only means of accurate diagnosis.

Acquired Immunodeficiency Syndrome↗

PubMed1986

Comparison of immunoblot analyses of spherule-endospore-phase extracellular protein and mycelial-phase antigen of Coccidioides immitis.

The extracellular proteins produced by Coccidioides immitis during growth of the spherule-endospore-phase and mycelial-phase antigen (coccidioidin) were studied by polyacrylamide gel electrophoresis followed by immunoblot analysis to detect specific serologic function. Filtrates obtained from 28- and 120-h growth of the spherule-endospore phase were compared with each other and with coccidioidin by using negative, immunoglobulin M (IgM) precipitin-positive, or complement fixation-positive pooled and single human sera followed by peroxidase-labeled anti-human IgA, IgE, IgG, or IgM (heavy chain specific) or peroxidase-labeled concanavalin A to detect the reaction. A total of 35 bands was seen in the stained gels. Different patterns were noted among the two spherule-endospore preparations and unheated and heated coccidioidin. At least 15 electrophoretically separate antigens were detected with positive serum ranging in approximate molecular weight (Mr) from 100,000 to 18,000. Most were clustered between 45 and 60 kilodaltons (kDa). Common bands were noted at 48 and 18 kDa. At least one band at 48 kDa was strongly reactive with complement fixation-positive serum demonstrated by reaction with anti-IgG and anti-IgE. In contrast, doublet bands in the 50- to 65-kDa area were highly reactive with IgM precipitin-positive serum detected by anti-IgM. IgM antibodies present in both positive sera reacted with a band at 46 kDa which was not reactive with IgG. Heating the antigens altered the reactivity of many of the antigens, including the 48-kDa band, but not the 46-kDa band.

Antigens, Fungal↗

PubMed1985

Guanine plus cytosine content of the DNA of Coccidioides immitis.

The mole per cent guanine plus cytosine was determined for DNA extracted from Coccidioides immitis to add information pertinent to the taxonomy of this zoopathogenic fungus. Four strains of C. immitis, three in the mycelial phase, one in the spherule/endospore phase yielded guanine plus cytosine in the narrow range of 49.41 to 49.61 mole percent. These values are lower than those for ascomycetes that mimic the arthroconidial form of C. immitis, higher than those for ascomycetous yeasts, but closer to those of 'transition zone' or basidiomycetous yeasts.

Coccidioides↗