Search

Using a reproducible model of Candida albicans keratitis in rabbits we studied the effect of topical fluconazole, a new triazole. Candida albicans DSM 70010 (2.5 X 10(5) cells) was injected into the corneal stroma of both eyes of 21 rabbits. All eyes developed a corneal ulcer. Forty-eight hours after inoculation the animals were divided into three groups: (1) 14 eyes, received fluconazole (2 mg/ml) and the epithelium subsequently removed; (2) 14 eyes, received only fluconazole drops; (3) 14 eyes, received 0.9% NaCl: half of this group was also debrided. We applied one drop of either substance 10 times a day for 24 days. A further six rabbits were used to judge if the drug penetrated into the cornea and aqueous humour. There was a highly significant difference between the fluconazole groups (1,2) and the control group (3) as to hypopyon and complications (descemetocele, corneal perforation) as well as recultivation of C. albicans from corneal tissue. The difference between the fluconazole groups with and without debridement was not significant. The drug penetrated into the cornea and aqueous humour of both uninflamed and inflamed eyes. [ABSTRACT FROM PUBLISHER]

The in vitro activity of posaconazole plus amphotericin B against conidia and hyphae of 30 clinical zygomycetes was investigated. The combination of posaconazole with amphotericin B was found to be significantly more synergistic (40%) against hyphae (P < 0.05) than against conidia (10%). Antagonism was not observed.

Currently, susceptibility testing of Aspergillus isolates towards caspofungin is hampered by a lack of interpretative cut-off values. Nevertheless, caspofungin has been widely recommended for the treatment of invasive aspergillosis. This antifungal, however, could lead to therapy failure as demonstrated by the case in this report of a 55-year-old patient, who eight months after the diagnosis of leukemia and successful allogenic hematopoietic stem cell transplantation (HSCT), succumbed to a fatal pulmonary aspergillosis infection, which resisted treatment with caspofungin.

A biphasic outbreak of methicillin-resistant Staphylococcus aureus in intensive-care units of a German tertiary-care hospital afflicted 89 patients within 4 years. The spread of the outbreak most likely was facilitated by the contamination of mobile radiograph equipment. The outbreak was controlled by measures of hospital hygiene.

A serine proteinase (Alp) from the culture supernate of a clinical isolate of Aspergillus fumigatus was purified to virtual homogeneity at a yield of 41%. The procedure involved affinity chromatography on agarose-epsilon-amino-caproyl-D-tryptophan methyl ester. Alp had an estimated mol. wt of 32 Kda and the pI was determined at pH 7.9. The enzyme was fully inhibited by phenylmethyl sulphonyl fluoride, chymostatin and alpha-1-proteinase inhibitor, and it was largely inhibited by alpha-1-anti-chymotrypsin. Partial inhibition was observed with tosyl-phenylalanine chloromethyl ketone, but tosyl-lysine chloromethyl ketone was ineffective. Thus, Alp may be identical with the major chymotryptic activity of A. fumigatus, which has already been described. The N-terminal sequence of 25 amino acids revealed an 88% homology of Alp with the subtilisin-related proteinase of A. oryzae. Alp acted on casein over a broad range from pH 5.5 to 11.5 and also acts to a lesser extent on haemoglobin and serum albumin. The enzyme degraded elastin and a synthetic elastase substrate; hence, it may be identical with the previously described elastinolytic activity of the fungus. At pH 7.3 and a concentration of 1 microgram/ml, Alp was not toxic for Vero cells, but it efficiently detached such cells from a plastic surface. Specific antibodies against Alp were detected by enzyme immunoassay in the sera of patients and Alp-antigen was demonstrated by immunofluorescence in mycotic human lung. In addition, a second proteinase (Exalp) with extremely alkaline activity, and an aspartic proteinase of A. fumigatus are described.

This study was designed to establish whether fluctuation in cervical mucus peroxidase concentration correlates with the cyclic pattern of the menstrual cycle hormones in the human female. Forty healthy, normal-cycling women between the ages of 19 and 29 years were chosen for the study. Blood samples and cervical mucus were collected on days 6, 9 through 15, and 17 through 19 of the menstrual cycle for three consecutive cycles in each volunteer. Blood estrogen, progesterone, follicle-stimulating hormone, and luteinizing hormone levels were quantitated by radioimmunoassay, and cervical mucus peroxidase concentrations were measured spectrophotometrically. The data showed that in the typical menstrual cycle the mucus peroxidase peak was reached immediately prior to the luteinizing hormone/follicle-stimulating hormone surge and coincided with the estrogen peak. Consistent data in three consecutive menstrual cycles in each volunteer led us to postulate that the mucus peroxidase peak during the menstrual cycle precedes the ovulatory period in the normal healthy woman.

We have studied purified acetylcholine receptor proteins from Electrophorus electricus and Torpedo marmorata which function in both binding and reconstitution experiments. The molecular properties of these receptor-channel complexes were analyzed under non-denaturing conditions by polyacrylamide gradient gel electrophoresis, ultracentrifugation sedimentation studies and laser light scattering. The purified receptor proteins exist in different interconvertible forms depending on both the type and concentration of detergent present, and the presence or absence of an intersubunit disulfide bridge. Receptor purified in the absence of sulfhydryl-blocking agents exists in two monomeric and two dimeric forms at very low detergent concentrations (0.01-0.05% Tween 80). At intermediate detergent concentrations (0.4% Triton X-100) one monomeric and one dimeric form are present. Only the monomeric form remains at high levels of detergent (2% Triton X-100). This form has a sedimentation coefficient of 9.29 S, as measured by ultracentrifugation using Schlieren optics. If receptor is purified in the presence of sulfhydryl-blocking agents, conversion of dimers into monomers by high concentrations of detergent does not occur. Disulfide-reducing agents convert dimers into monomers independent of whether the receptor's free sulfhydryl groups are blocked or not. These findings imply that dimer formation is primarily due to hydrophobic interactions between monomers. When these interactions are reduced by high levels of detergent the intersubunit disulfide bridge is dissociated at the expense of newly formed interasubunit ones, as long as the sulfhydryl group(s) have remained unblocked. Monomers and dimers bind alpha-cobratoxin with the same affinity and kinetics. Dimers of disulfide-linked monomers are not required for the reconstitution of a functional ion-translocation system. The presence of EDTA during the purification of receptor proteins (as recommended by many groups to inhibit proteolysis) adversely influences the activity of the receptor in channel gating. These observations are discussed in terms of the requirements for a purification procedure yielding receptor preparations unaffected by proteolysis and functioning in both binding and ion translocation. The molecular weight of the receptor monomer was determined by several independent techniques and yielded values in the range of 250-300 x 10(3). With a translational diffusion constant D20, w = 2.95 x 10(-7) cm2 s-1 and a sedimentation coefficient s20, w = 9.29 S, the frictional coefficient ratio f/f0 = 1.51 was calculated for the receptor monomer from Torpedo marmorata. This indicates a considerable asymmetry in the shape of the detergent-solubilized receptor.