Growth-inhibitory and membrane-damaging effects of terbinafine on Sporothrix schenckii were compared between the wild strains sensitive to terbinafine and tolciclate and the mutant strains tolerant to tolciclate.
The tolciclate-resistant mutant strains were in two types, one lacking squalene epoxidase activity and the other not, and both cross-resistant to terbinafine and naftifine, when referring to concentration for 50% growth inhibition.
Sensitivity to membrane-damaging action by terbinafine of each of the types was compared with that of the wild type by measuring extracellular release levels of K⁺ and inorganic phosphate. The squalene epoxidase-deficient type showed a slight decrease of sensitivity, while the nondeficient type showed a marked decrease.
These findings suggest that (1) squalene epoxidation is primarily associated with antifungal activity of both terbinafine and tolciclate, and that (2) direct membrane-damaging action is also responsible for the antifungal action at higher concentration of the drugs in fungal such as S. schenckii which are highly sensitive to terbinafine.

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In order to determine the antifungal mechanism of terbinafine (TBF), a new allylamine antimycotic, antifungal action of the drug was compared with that of tolciclate (TOL), a thiocarbamate antimycotic which inhibits squalene epoxidation in the pathway of fungal sterol synthesis, using C. albicans as a test organism. The results are summarized as follows.
1) TBF even at low concentrations (<1μg/ml) inhibited to some extent the growth of C. albicans: almost complete inhibition was seen at concentrations of >5μg/ml, while TOL did not inhibit even high (80μg/ml) concentration.
2) The decrease of ergosterol content and accumulation of squalene in cells were observed even at low consentrations (<0.3μg/ml) of TBF; a similar result was obtained for TOL at 80μg/ml.
3) TBF, at 10μg/ml or more concentration, accelerated the release of K⁺ and inorganic phosphate from C. albicans cells, although TOL did not at all, indicating that TBF directly damages the cell membranes at high concentrations of the durg.
These results suggest that TBF partially inhibits the growth of C. albicans by inhibiting ergosterol synthesis at low concentration and, in addition, completely inhibits it by directly damaging the cell membranes at high concentrations.

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Tolciclate is a thiocarbamic acid derivative with a potent antidermatophytic activity. The effects of the drug on the morphology of growing hyphae of Trichophyton mentagrophytes were studied with a high resolution scanning electron microscope. Control hyphae which were cultured for 48h without the drug grew vigorously. They had uniform widths and their surfaces were smooth. None of the cell debris was attached to the hyphal surface. In contrast, hyphae treated with the drug for 48h showed four different types of morphologycal depending on the drug concentration. i) When grown with 0.02-0.3ng/ml of the drug, no growth inhibition was noted, however, deformed, flattered and shrunken hyphae were occasionally observed. ii) When grown with a concentration of 1.3-lt;20ng/ml, incomplete growth inhibition occurred and elongation of hyphae was partially arrested. The hyphae were enormously swollen. iii) When grown at the fungistatic drug concentration (20-80mg/ml), most of the hyphae ceased to grow and profound shrinking and flattening were observed. iv) When incubated with the fungicidal drug concentration (≥320ng/ml), they were enormously swollen and their cytoplasmic materials were released in great quantity into the medium. These dose-dependent morphological changes were discussed in connection with tolciclate's biochemical basis of action.

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We recently encountered a case of cryptococcosis (cryptococcal meningitis). As a serological test, we used the latex agglutination (LA) test for antigen detection. This test is known to be useful in the diagnosis of cryptococcosis. Antigens were detected, and the time course of the titer of cryptococcal antigen in the cerebrospinal fluid aided our evaluation of the treatment. We measured miconazole and flucytosine (5-FC) concentration in serum after intravenous administration of the former or oral administration of the latter. We also measured concentration of the drugs in cerebrospinal fluid after intrasubarachnoidal space administration or intravenous administration of miconazole or oral administration of 5-FC.
Intravenous administration of a large amount of miconazole resulted in successful treatment without serious side effects. Therefore, the combination therapy of intravenous administration of a large amount of miconazole and oral administration of 5-FC is considered effective for treatment of cryptococcus meningitis.

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A resected case of an asymptomatic, solitary nodule in the lower lobe of the right lung due to mucormycosis is reported. A healthy 50-year-old man was first found to have a pulmonary nodule during by an annual health examination. Right lower lobectomy was performed on suspicion of a malignant neoplasm. The surgical specimen revealed a yellowish-white, necrotizing tumor approximately 4.0cm in diameter. Histologically, many foreign body granulomata around central abscesses were observed, surrounded by extensive lympho-plasmacytic infiltration. Scattered irregular-shaped, non-septated, eosinophilic fungal elements were present in the abscess and granulomata. Immunohistochemically, the fungal elements were stained positively with anti-Rhizopus oryzae antibody.
This was a case of mucormycosis in a healthy person.

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A method of evaluating the clinical and mycological effect on tinea capitis due to Microsporum canis was studied. All ten patients were infants, and they were treated with oral griseofulvin or itraconazole. After treatment the clinical findings were easily evaluated by crusts and scales on the lesions. Mycologically, hairs ware examined by the direct KOH method, the culture, and the hairbrush method. Periods of treatment were 8 to 14 weeks (average 11.7). Positive clinical findings were made between 2 to 14 weeks (average 8.3). The average of positive findings in the mycological examinations were 2.6 weeks by the direct examination of hairs, 1.9 weeks by the culture and 5.1 weeks by the hairbrush method.
We can thus conclude that crusts and scales on the lesions were important in evaluating the clinical effect, and that the hairbrush method was most useful in the determining the mycological effect on tinea capitis.

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The clinical course of forty autopsy cases with leukemia was investigated to assess factors associated with the development of visceral mycosis.
From the results of multivariate analysis, the number of total leukocytes (X 1), neutrophils (X 2), lymphocytes (X 3), and monocytes (X 4) in peripheral blood, the number of consecutive days indicating leukocyte count below 1, 000/μl and the body temperature were selected as effective factors to discriminate cases with visceral mycosis from others.
The following formula derived from the linear discriminant analysis of the above factors gave the best result to classify autopsy cases.
Z=-100.5427-0.00401·(X2)-0.01057·(X4)+0.05622·(X6)+2.61331·(W1)
If Z is more than 0, the case is classified in the mycosis group.
Using this formula, all of 21 autopsy cases with mycosis were classified correctly to the mycosis group and the only 2 of 19 autopsy cases without mycosis were incorrectly identified as being in the mycosis group. Applying the formula to clinical cases with leukemia, 7 out of 8 cases with mycosis and 12 out of 15 without mycosis were predicted correctly.
These results suggest that the newly established risk index will be useful in making an early prediction and starting the empiric therapy for mycosis in leukemic patients.

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