Influence of food on the pharmacokinetics of ketoconazole

Eight healthy adults were given single oral doses of ketoconazole (200, 400, 600, and 800 mg) in the fasting state and with a standard breakfast at weekly intervals according to a balanced block design. Concentrations in serum were measured up to 32 h after the dose. Food did not reduce ketoconazole absorption or significantly alter peak ketoconazole concentrations in serum, though there was a food-related delay in achieving peak concentrations. At the 400- and 600-mg doses, food appeared to enhance absorption, but this effect was not seen at the 800-mg dose. With an increase in dose, the half-life and area under the serum concentration-time curve increased disproportionately, suggesting that the pharmacokinetics of ketoconazole may be dose dependent. Up to the 800-mg dose, the elimination of ketoconazole did not appear to be saturable. Administration of the drug with food is unlikely to be a cause of therapeutic failure.

Evaluation of an enzyme-linked immunosorbent assay (ELISA) for the diagnosis of Aspergillus fumigatus intranasal infection of the dog

ELISA appears to be a less reliable method than counterimmunoelectrophoresis for the diagnosis of nasal aspergillosis in the dog. False-positive or false-negative results were recorded for anti-A. fumigatus IgG in nine animals with aspergillosis and in 27 disease-free dogs although this problem could be reduced with careful selection of antigen.

Evaluation of a rapid enzyme-linked immunosorbent assay for IgG antibodies to Aspergillus fumigatus in the serological diagnosis of allergic aspergillosis

A range of 6 somatic and culture filtrate antigens of Aspergillus fumigatus were evaluated in a rapid ELISA procedure for anti-A. fumigatus IgG where the component incubation times had been reduced to 10 min. Sera from patients with allergic aspergillosis, patients with suspected allergic aspergillosis, and asthmatic patients with or without A. fumigatus precipitins were tested. For all antigens, levels of anti-A. fumigatus IgG were higher in patients with allergic aspergillosis than in the other 3 groups. Low levels of specific IgG were, however, detected in asthmatic patients who had no precipitins against A. fumigatus. None of the antigen preparations enabled all patients with proven or suspected allergic aspergillosis to be separated from the other 2 groups of asthmatic patients. Positive-negative discrimination in ELISA was achieved by the inclusion of 10 pools of precipitin test-negative sera from the 50 asthmatics without A. fumigatus precipitins. The number of sera that were classed as positive in ELISA ranged from 9 to 15 in the allergic aspergillosis group, depending on the antigen used; in the suspected aspergillosis group, the number of positive reactions ranged from 1 to 8, while in the asthmatics with precipitins, the number ranged from 0 to 2.

Effect of imidazole antifungals on the development of germ tubes by strains of Candida albicans

Three imidazole antifungals (ketoconazole, tioconazole and miconazole) were examined for their effect on germ tube development by synchronous blastospore populations and on actively growing germ tubes of three strains of Candida albicans. After incubation in serum for 4 h the largest differences in germ tube elongation between strains were detected at concentrations (0.005 mg/l) where minimal inhibition was observed. Germ tube elongation in antifungal-containing serum diminished with increasing concentration. Maximum inhibition occurred at concentrations of 0.5 mg/l. All three antifungals inhibited the rate of hyphal elongation by the strains over a 6 h period at this concentration. Tests where germinated blastospores of strain 3281 were transferred to serum containing 0.5 mg/l of antifungal indicated that all three drugs inhibited further elongation. However, the rate of inhibition was dependent upon the length of time germination had proceeded in serum alone prior to transfer to antifungal-containing serum.

Multiple dose pharmacokinetics of ketoconazole and their effects on antipyrine kinetics in man

Ketoconazole 200 mg was given twice daily for five days to eight subjects. The serum pharmacokinetics were examined with the first dose on day 1 and with the ninth dose on day 5. The serum half life of ketoconazole was 74.8 +/- 13.9 min (mean +/- S.D.) on day 1, and 155.9 +/- 32.7 min on day 5. On day 1 the area under the serum concentration time curve was 626.9 +/- 230.1 mg/l.min, and 1441 +/- 897.3 mg/l.min on day 5. Antipyrine kinetics were determined before and after the course of ketoconazole. There was no significant change in the clearance and half life of antipyrine. Ketoconazole in the doses used in this study does not appear to alter hepatic microsomal enzyme activity in man. The increased ketoconazole half life and area under the serum concentration time curve on day 5 were in part caused by food. Other mechanisms for these changes such as saturation of a tissue compartment or a change in the elimination of ketoconazole during chronic dosing, may also be responsible.

Further evaluation of factors affecting a rapid ELISA procedure for detection of IgG antibodies to Candida albicans

A rapid enzyme-linked immunosorbent assay (ELISA) was developed to detect IgG antibodies against a cytoplasmic antigen of Candida albicans. The optimum conditions and time required for each step were investigated. Pre-equilibration at 37 degrees C and constant agitation of immunoreactants resulted in a total test time of 1 h for examination of single serum dilutions. Initial binding of the antigen at 37 degrees C to the solid phase occurred within 4-6 min and was dependent on concentration. A serum dilution of 100-fold resulted in adequate discrimination between precipitin test-positive and -negative sera. Interaction of antibody and the bound antigen was maximal after 6 min incubation at 37 degrees C and was dependent upon the precipitin titre of the serum. Ten minutes was selected as the optimal incubation time for each of the stages, by which time maximal binding had occurred, irrespective of antibody affinity for antigen. The ELISA was completed by incubation at 37 degrees C for 10 min with alkaline phosphatase-conjugated anti-human IgG. Discrimination between positive and negative test sera was achieved by incorporating in each test run precipitin test-positive and -negative reference sera from groups of persons with or without C. albicans colonization or infection. Closest agreement between sera positive for C. albicans precipitins by counter-immunoelectrophoresis and the rapid ELISA was seen when reference negative sera were selected from non-colonized individuals.

Grass pollen concentrations in the U.K

A CENSUS of grass pollen concentrations was under taken at 9 sites throughout the U.K. in 1977. Large differences were noted between concentrations on indi vidual days and peak concentrations occurred later at the Northern sites.

Computer-assisted rapid enzyme-linked immunosorbent assay (ELISA) in the serological diagnosis of aspergillosis

A computer-assisted method for the positive/negative discrimination of ELISA data is described. This method was applied to a rapid ELISA procedure for IgG class antibodies to Aspergillus fumigatus in which the performance time of the test was reduced to 1 h. The method gives results which compare well with those by agar gel double diffusion (AGDD). The computer-assisted reading, calculation and tabulation of ELISA results from one microtitre plate is performed in less than 2 min and permits analysis of large numbers of specimens.

Rapid enzyme-linked immunosorbent assay (ELISA) for Aspergillus fumigatus antibodies

A rapid enzyme-linked immunosorbent assay (ELISA) where component incubation periods were shortened to one hour, was compared with agar gel double diffusion (AGDD) and a standard ELISA procedure for detecting antibodies to Aspergillus fumigatus in 28 asthmatic patients with suspected allergic aspergillosis. Using two A fumigatus antigens the rapid ELISA compared well with AGDD and the standard ELISA method. Eleven sera that reacted with both antigens in AGDD were all positive against antigen 1 in both forms of ELISA, but two failed to react with antigen 2 in the standard ELISA and three failed to react with this antigen in the rapid method. Thirteen AGDD-negative sera were also negative in both forms of ELISA. The rapid ELISA provides a sensitive and reproducible test for routine serological investigation of allergic aspergillosis.

Rapid serological diagnosis of Aspergillus fumigatus infection of the frontal sinuses and nasal chambers of the dog

Aspergillus fumigatus precipitins in dog sera were detected by counterimmunoelectrophoresis (CIE). The procedure gave results within 90 minutes compared with 72 to 96 hours required in agar-gel double diffusion. Culture-filtrate antigens from two-week-old cultures of A fumigatus and two-day-old mycelial antigens produced the strongest reactions in CIE tests and the former antigen also revealed high titres in tests with serum from seven of 14 dogs with A fumigatus precipitins. Serum from these 14 dogs also reacted in CIE tests with a number of Penicillium species antigens.

Further evaluation of indirect immunofluorescence methods for detection of antibodies against Aspergillus fumigatus

The IF titres of IgG antibodies to hyphal antigen preparations of 6 isolates of Aspergillus fumigatus were compared with the titres to germling antigen preparations of the same isolates. Titres varied according the antigen used and the method of preparation. No single isolate or method of antigen preparation enabled a group of 15 patients with aspergillosis to be separated from a group of asthmatic subjects or a group of patients with other fungal infections, but significantly higher means IF titres were obtained for the group of patients with aspergillosis.

Antibodies to Candida species after operations on the large intestine: observations on the association with oral and faecal yeast colonization

The occurrence of agglutinating and precipitating antibodies to Candida species was determined in 50 patients undergoing operations on the large intestine. The number of patients with oral or faecal yeast colonization and the amount of faecal colonization increased during the period after operation. No patient developed overt fungal infection but 15 patients developed precipitins to mannan antigens and 9 patients developed percipitins to cytoplasmic antigens during this period. The association between the formation of precipitins and the extent of faecal colonization is discussed.

Epidemiological investigation of patients with vulvovaginal candidosis. Application of a resistogram method for strain differentiation of Candida albicans

The resistogram method was applied to 420 isolates of Candida albicans obtained from 30 selected patients undergoing treatment for vulvovaginitis. Of these, 16 patients each harboured a particular strain of C. albicans which persisted in the mouth or intestinal tract or both. In three of these patients, this strain persisted in the genital tract, and, in eight patients, it later recolonised the genital tract. Fourteen patients harboured more than one strain of C. albicans: one failed to respond to treatment and continued to harbour the same strain in the genital tract; in five the original strain later recolonised the genital tract and a second strain remained confined to the mouth or intestinal tract or both; and in three a second strain, present in the intestinal tract, later colonised the genital tract. Each of the male partners of seven patients harboured a strain of C. albicans that was identical to the strain, or to one of the strains, that had been isolated from his female partner.