Gillian S. Shankland

Opsonizing activity of C-reactive protein in phagocytosis of Aspergillus fumigatus conidia by human neutrophils

Summary. In complement‐free neutrophil mono‐layer assays pathological levels of C‐reactive protein (CRP) were found to promote greater phagocytosis of metabolically‐active conidia of Aspergillus fumigatus than dormant spores. This suggests that metabolically‐active conidia bind CRP which facilitates in vitro phagocytosis by human neutrophils.

Enhanced phagocytosis and intracellular killing of Pityrosporum ovale by human neutrophils after exposure to ketoconazole is correlated to changes of the yeast cell surface

Summary. In seborrhoeic dermatitis an inflammatory response occurs secondary to large numbers of Pityrosporum yeasts appearing within and beneath the epidermis. To study the interaction between human neutrophils and P. ovale and any im‐munomodulating effect of antifungal agents, the yeast was exposed to ketoconazole and then incorporated into neutrophil monolayer assays. Phagocytosis was complement dependent and reached a maximum after 40 min. Ketoconazole at 25, 50 and 100 mg 1‐1 had no significant effect on phagocytosis of P. ovale. However, when yeast cells were pre‐treated with ketoconazole for 2 h before exposure to the phagocyte monolayer there was a significant enhancement of phagocytosis with increasing drug concentration. Intracellular killing of P. ovale was assessed by methylene blue dye exclusion. In the absence of ketoconazole, 5% of intracellular yeast cells were killed following internalization for 2 h. Pretreatment of yeast cells with ketoconazole at 10 and 100 mg 1‐1 for 2 h prior to ingestion significantly increased intracellular killing to a maximum of 23%. This study demonstrates that yeast cells of P. ovale are readily ingested by human neutrophils by a complement dependent process. Phagocytosis is enhanced if the organism is exposed to ketoconazole before opsonisation and ingestion. The inability of neutrophils to kill P. ovale is modulated in the presence of therapeutic concentrations of ketoconazole.

In vitro susceptibility of Trichophyton mentagrophytes arthroconidia to clotrimazole and griseofulvin in human corneocyte suspensions

Summary. The use of corneocytes in suspension as a medium for the study of the effect of antifun‐gal drugs on Trichophyton mentagrophytes arthroconidia was investigated. In the presence of clotrimazole or griseofulvin, arthroconidia germination in a suspension of corneocytes and in Sabouraud glucose liquid medium was significantly reduced compared with germination in drug‐free media. Where antifungals were added to arthroconidia after an activation period during which germination occurred, any further germination was inhibited. The data showed that the growth of T. mentagrophytes in the presence of corneocytes offered a simple, rapid, inexpensive and relevant model for the assessment of antifun‐gal activity of compounds for the treatment of dermatophytosis.

Treatment of experimental dermatophytosis in guinea pigs: a comparative study of bifonazole and a bifonazole-hydrocortisone combination.

Summary: Five groups often guinea pigs infected with Trichophyton mentagrophytes var. mentagrophytes were evaluated in a blind study to investigate the advantages of incorporating hydrocortisone with bifonazole for the treatment of dermatophytosis. One group contained the untreated animals and the other groups we treated daily with: bifonazole alone, hydrocortisone alone, bifonazole/hydrocortisone combination or vehicle alone. The mycological, clinical and histopathological progression of the disease was monitored for three weeks. The two groups receiving the antifungal were the most impressive clinically. This was confirmed mycologically and although there was evidence of fungus on histological examination, the stratum corneum showed signs of recovery. In the three groups not receiving antifungal therapy the infection did not resolve by the end of the treatment period. Animals from these groups were mycologically positive throughout the treatment period and histological examination showed proliferation of the fungus. The groups were ranked in descending order as bifonazole/hydrocortisone combination, bifonazole alone, hydrocortisone alone, vehicle alone, untreated control.

Intracellular killing of Candida albicans by human neutrophils is potentiated by exposure to combinations of amphotericin B and 5-fluorocytosine

Summary. Combination treatment with amphotericin B and 5‐fluorocytosine is synergistic and has become clinically useful in the treatment of various forms of systemic candidosis. The synergy between these two compounds may be explained in part by their combined effect on the interaction between fungal cells and host phagocytes. Pretreatment of Candida albicans for 2 h with either amphotericin B or 5‐fluorocytosine or the two agents in combination did not inhibit or enhance phagocytosis by glass‐adherent human neutrophils (P >0.05). Intracellular killing of pretreated yeast cells was not influenced by antifungals alone (P >0.05), but pretreatment of C. albicans with 5.0 mg 11‐ amphotericin B + 10 mg 1‐1 5‐fluorocytosine or 5.0 mg 1‐1 amphotericin B + 50 mg 1‐1 5‐fluorocytosine significantly enhanced the ability of neutrophils to kill the number of viable yeast cells intracellularly (P<0.001)

Comparative activity of miconazole cream and ointment in the treatment of experimental dermatophytosis in guinea pigs

Summary:  Two formulations of miconazole nitrate were evaluated to determine their efficacy in the treatment of experimental Trichophyton mentagrophytes var. mentagrophytes infections of guinea pigs. Cream and ointment formulations of the drug containing 1% hydrocortisone were applied daily to groups of infected guinea pigs for a 21 day period. Animals were assessed clinically and histopathologically. Early resolution of infection was seen on cream‐treated animals but there was mild inflammation and ulceration on those treated with the ointment formulation. This finding was supported by the histological appearance. However, by the end of the treatment period both groups of animals were completely clear of infection. This similarity in clinical response between the two formulations at the end of the treatment period was confirmed by the abscence of fungus in skin sections.

Effect of amorolfine (Ro 14-4767/002) on in vitro phagocytosis and intracellular killing of Candida albicans by human neutrophils

Summary: The effect of amorolfine (Ro 14–4767/002) on phagocytosis and intracellular killing of Candida ulbicuns blastospores was determined in human neutrophil mono‐layer assays. At 0.2, 2 and 5 p, g/ml amorolfine did not have any significant inhibitory or enhancing effect on phagocytosis whether following simultaneous addition of blastospores and drug to the neutrophils, prior treatment of neutrophils for 2 h before addition of blastospores or prior treatment of blastospores for 2 h. Simultaneous addition of amorolfine resulted in a significant increase in killing at all concentrations. This increase was not significantly enhanced by either preincubation of neutrophils or blastospores for 2h with the drug.

Cerebral candidiasis in a child 1 year after leukaemia

We describe an unusual case of a late presentation of a fungal brain abscess in a non‐neutropenic child 1 year after completing chemotherapy for M5 acute myeloid leukaemia (AML). Biopsy of the mass identified candidal hyphae and the patient was treated with 5 mg/kg of liposomal amphotericin B for 6 weeks. The lesion resolved completely and the child remains well 2 years later. Invasive fungal infection should be included in the differential diagnosis of unexplained symptoms in patients who have previously received intensive chemotherapy.

Activity of topically applied leukotriene B4 in experimental dermatophytosis

Zusammenfassung. In einer Pilotstudie zur Aufklärung der antimykotischen Wirksamkeit des Chemoattraktans Leukotrien B4 (LTB4) wurden Meerschweinchen mit Trichophyton mentagrophytes var. mentagrophytes infiziert und in folgende Versuchsgruppen eingeteilt: 1. Unbehandelte Kontrolltiere; 2. Tiere, behandelt mit LTB4 plus Vehikel; 3. Tiere, behandelt mit Isoconazolnitrat plus Vehikel; 4. Tiere, behandelt mit dem Vehikel allein (10% Isopropylmyristat in Ethanol). Die Tiere wurden klinisch, mykologisch und histopathologisch bewertet. Die Behandlung mit Isoconazolnitrat war die wirksamste. Die LTB4‐behandelte Gruppe war klinisch in einem schlechteren Zustand als die nichtbehandelte Gruppe, und die Pilzkulturen blieben die ganze Beobachtuneszeit über positiv.