Saburo Kagawa

Local Hyperthermia in the Treatment of Sporotrichosis. Die lokale Hyperthermie in der Sporotrichose‐Behandlung

Summary:  21 patients with sporotrichosis underwent treatment of local hyperthermia using a pocket warmer. The treatment was performed 1–3 times a day, totalling 40–60 minutes per day, until the lesions healed with scarformation. As a result, “complete cure” was observed in 18 patients, “relapse” in 1 and “improvement” in 2. In the 18 patients with complete cure, the period of treatment was 5–13 weeks (mean ± SD: 8.5 ± 2.5 weeks), and was not affected by sex, age, sites of lesions or clinical types. Because heat resistant strains were not detected by thermotolerance tests of isolates, the reason for failure was suspected to be mainly due to the misuse of the pocket warmer. It was, therefore, thought that the application technique of a pocket warmer was the most important factor in the success of the local hyperthermic therapy.

Isolations of dermatophyte from clinically normal scalps in M. canis infections using the hairbrush method.

The scalp hair of patients with dermatophytosis due toM. canis but without scalp lesions, and that of their family members without dermatophytosis were examined using the hairbrush method. The dermatophyte was detected in 93.8% of the scalps of those who lived in homes where cats were kept, and in 25% of those without cats. After the source of infection had been treated, the dermatophyte showed a gradually decreasing presence, finally disappearing altogether, so that no case of the disease on the scalp hair could be found.We inferred from the above findings inM. canis infections that, since the dermatophytes are seen in a high proportion of cases without scalp lesions, the dermatophytes, in many cases, exist only as saprophytes on the hair.

The effects of heat on Sporothrix schenckii in vitro and in vivo

In order to clarify the mechanism of action of topical thermotherapy on sporotrichosis, the effects of heat on Sporothrix schenckii in vitro and in vivo were investigated by observing the percentage germination and the ultrastructure. When the spores were heated to 42° C, it took 10 hr with the conidia, 2 hr with the yeast-like cells and 1 hr with the spores in vivo to reduce the germination rates to 10%. The percentage germination curves were reduced slowly at first but later exponentially. Changes in the ultrastructure became evident in 2 hr with the yeast-like cells and in 8 hr with the conidia. The ribosome count declined and amorphous dense materials appeared in the cytoplasm and mitochondria. In vivo, the outstanding feature of the heated spores was the diversity of internal ultrastructural changes encountered and morphological changes. These were observed at 1 hr post treatment.

Effects of hyperthermia on phagocytosis and intracellular killing of Sporothrix schenckii by polymorphonuclear leukocytes

The effects of hyperthermia on phagocytosis and killing of Sporothrix schenckii by polymorphonuclear leukocytes (PMNs) were investigated in order to clarify the mechanism of local thermotherapy for sporotrichosis. Yeast cells of S. schenckii, PMNs and serum were incubated at 37°C or 40°C for 2 or 4 hours. Rate of phagocytosis and killing rate (rate of germination) were estimated, and their processes were observed by transmission electron microscopy. There was no effect of hyperthermia on the phagocytosis rate, but the killing rate increased significantly at 40°C. Electron microscopic examination showed an increase of granularity in the yeast cytoplasm, elongation and fragmentation of the cell membrane. The ultrastructural changes were basically identical under both temperatures, but the degree of these changes was higher at 40°C than at 37°C. Although both intact and degenerated yeasts were found in the same conditions, their transient forms were few, suggesting that the PMN-killing process was completed promptly.

The Pathogenicity of Beauveria bassiana in the Rabbit Cornea/Pathogenität von Beauveria bassiana für die Cornea des Kaninchens

Summary: To study and compare the pathogenicity of Beauveria bassiana with that of Candida albicans in the cornea, we produced experimental B. bassiana and C. albicans keratitis in rabbits and studied the infected eyes clinically and histopathologically. The corneal lesions were examined every day for three weeks and the severity of infections was compared. For histopathologic study, the eyes were enucleated at various times. B. bassiana produced substantially less severe clinical infections in the cornea, compared to C. albicans. Histopathologically, B. bassiana showed little growth in the cornea, and no invasion into the anterior chamber. We considered that B. bassiana has very weak pathogenicity in the cornea, which may explain the small number of cases of keratomycosis caused by this fungus.

Ultrastructure of Sporothrix schenckii treated with iodine-potassium iodide solution

The ultrastructural changes produced by iodine-potassium iodide solution on yeast cells of Sporothrix schenckii were investigated by transmission electron microscopy in order to clarify the mechanism of oral potassium iodide therapy for sporotrichosis. Yeast cells were dipped with solutions containing various concentrations of iodine. The rate of germination decreased markedly between the range of iodine concentrations from 0.63 μg/ml to 5.0 μg/ml. No significant ultrastructural changes were seen at the concentration of the iodine of 1.25 μg/ml (80% germination) or less. In the concentration of 2.5 μg/ml (50% germination), normal cells and degenerated cells coexisted. When the cells were treated with 5.0 μg of iodine per ml (0% germination) or more, their interior structures were completely destroyed. It is assumed that iodine treatment of the organism causes rapid destruction in the whole cell.

The pathogenicities of Cylindrocarpon tonkinense and Fusarium solani in the rabbit cornea

The pathogenicity of Cylindrocarpon tonkinense in the cornea was evaluated and compared with that of Fusarium solani in rabbits. F. solani was inoculated into the right eyes of 14 rabbits and C. tonkinense was into the left eyes of same rabbits. The corneal lesions of both eyes were examined carefully by slit lamp every day for three weeks and the severity of infections were compared each other. For histopathologic study, several eyes were enucleated periodically. C. tonkinense has a pathogenicity equally strong as F. solani in this inculum size (104 microconidia per cornea) and produced severe infection in rabbit eyes.

Comparison of the pathogenicities of Fusarium solani and Candida albicans in the rabbit cornea

The pathogenicity of F. solani was compared with that of Candida albicans in experimental keratitis in rabbits. F. solani was inoculated into the right eye of each rabbit, and C. albicans into the left eye. The corneal lesions in both eyes were examined by slit lamp every day for 3 weeks and the severity of infections compared clinically and histopathologically. F. solani produced significantly more severe clinical infection in the cornea, compared to C. albicans. Histopathologically, F. solani appeared to spread more rapidly, enter the anterior chamber more easily, and produce a more severe inflammatory reaction in the cornea, compared to C. albicans.

A case of rectal carcinoma concomitant with pagetoid lesion in the perianal region

SummaryA case of extramammary Paget’s disease of the perianal area adjacent to a mucinous adenocarcinoma of the rectum is presented.The histopathological examination of the case revealed that within the epidermis adjacent to the invading rectal cancer nest, the formation of glandular structures can be observed occasionally, around which so-called Paget’s cells are noted to be scattered and further many points of similarity between cancer cell and Paget’s cell are proved by electron microscope. Perianal skin lesion looking like Paget’s disease is proved to be due to intraepidermal spread of the rectal carcinoma.Referring to the literature, this is the first report to our knowledge, to elucidate the histogenesis of perianal extramammary Paget’s disease associated with a rectal carcinoma using the electron microscopy.

Malassezia Intertrigo, a New Clinical Entity

Summary:  A Pityrosporum infection in a 17‐year‐old male is reported. The clinical symptoms were erythematous macules with fine scales and appeared in both antecubital fossae. In a direct examination and in cultures of the scales, large numbers of Pityrosporum ovale and a few Pityrosporum orbiculare cells were seen. The histopathological findings, which resembled those of tinea versicolor, revealed clusters of Pityrosporum ovale around the orifices of the hair follicles. When the lesions were treated by topical application of 1% clotrimazole cream they disappeared, but left areas of pigmentation behind. Since the above findings corresponded with those of the clinical entity described by Soh, the name Malassezia intertrigo, which he proposed, is employed in this report.