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M L Hsu

Publications and source records attributed to M L Hsu.

8 recordsLinked to original sources
PubMed1992

Pathogenesis of hair infection and black dots in tinea capitis caused by Trichophyton violaceum: a histopathological study.

The majority of tinea capitis in southern Taiwan occur in adult women and are caused by Trichophyton violaceum. We report the histopathological findings of a series of 10 cases of tinea capitis caused by T. violaceum, the largest such study to date. Our study provides new information regarding the process of hair infection, mechanism of black dot formation, and chronicity of infection caused by this fungus. The cuticle remains intact. The fungi enter the proximal cortex where the cuticle is immature. They then colonize the proximal keratinized cortex and generate septate hyphae which transform gradually into arthrospores as they are carried upwards by the growing hair. At the infundibular level, the hair cortex is almost completely replaced by spores and swells, impeding further exit of the growing hair and causing the already weakened hair to coil up inside the infundibulum, forming a black dot. In one patient who had infection for more than 20 years, there were changes suggestive of cyclic reinfection of the same follicles which might contribute to the chronicity of the infection.

Adolescent↗
PubMed1992

Cutaneous alternariosis in association with scabies or iatrogenic Cushing's syndrome.

Cutaneous alternariosis is rare. Most infections occur in immunocompromised hosts. We report the first three cases in Taiwan. The patients were elderly farmers residing in Tainan. They developed indolent, erythematous, ulcerated or crusted papules, plaques or pustules over the extensor aspect of the forearms or hands. Pure colonies of Alternaria sp were isolated from biopsy specimens in each case. The diagnosis was confirmed by detecting pleomorphic fungal elements in the dermis within suppurative, granulomatous infiltrates. All three patients were immunocompromised. They showed a negative reaction to an intradermal test of seven common antigens. Cases 2 and 3 had iatrogenic Cushing's syndrome. Cases 1 and 3 had extensive scabies, which in Case 1 was of the Norwegian type. To the best of our knowledge, scabies associated with alternariosis has not been reported previously. The infection showed spontaneous regression in Case 1; in Case 2, it resolved after seven weeks of intralesional amphotericin B at a dose of 1 mg/mL twice a week.

Aged↗
PubMed1991

Alopecia syphilitica, a simulator of alopecia areata: histopathology and differential diagnosis.

Alopecia syphilitica (AS) may be "moth-eaten" or diffuse, clinically, and be confused with alopecia areata (AA) or other alopecias. The English language literature contains scant information regarding the histopathology of AS, and the resemblance between AS and AA has not been given adequate recognition. We report the histopathological findings of AS from nine patients with secondary syphilis and acute hair loss. The alopecia was moth-eaten in four patients and diffuse, but slightly moth-eaten, in five. Microscopically, the dermoepidermal interface was not involved. The numbers of hair follicles were diminished, with increased numbers of catagens and telogens. Lymphocytic infiltration was present around the hair bulbs and fibrous tracts in eight cases. Plasma cells were present in four biopsies. Other less common findings included lymphocytes in the isthmus, parabulbal lymphoid aggregates, and granulomatous infiltrate in the upper dermis. The findings, save for the follicular changes, resembled those of macular/maculopapular syphilides outside the scalp. With the follicular changes, the overall patterns resembled AA closely. The modified Steiner stain did not reveal spirochetes in any of our cases and failed to differentiate between AS and AA. Comparing the AS cases to 13 cases of AA, we found only a few differentiating features. The presence of peribulbal eosinophils strongly suggests AA. Without peribulbal eosinophils, the presence of plasma cells, abundant lymphocytes in the isthmus, or parabulbal lymphoid aggregates suggests AS.

Adult↗
PubMed1991

In vivo stimulation of myelopoiesis in cyclophosphamide-treated mice by purified human GM-CSF.

Human granulocyte-macrophage colony-stimulating factor (hGM-CSF) secreted by a hepatoma cell line, HA22T/GVH, was purified and assessed for its effects in vivo on blood leukocytes and bone marrow granulocyte-macrophage progenitor cells (CFU-GM) in ICR mice pretreated with a sublethal dose of cyclophosphamide (cytoxan). The hGM-CSF preparations were natural and had no detectable endotoxin. Five days after the administration of 300 mg/kg cytoxan, severe leukopenia with marked myelopoietic suppression was induced. The cytoxan-treated mice were then injected intraperitoneally with 10,000 units of purified hGM-CSF/mouse daily for three days. Leukopenia was totally abrogated and the leukocyte number greatly increased to a level 2- to 3-fold higher than in GM-CSF-uninjected mice. Differential white cell count showed that the subpopulations of leukocytes responsive to hGM-CSF stimulation were mainly of neutrophils and monocytes, while the lymphocytes remained unaffected. Meanwhile, in the bone marrow, hGM-CSF administration induced an apparent (3-fold) increase in the number of myeloid progenitor cells, CFU-GM. However, the effect in vivo of a single hGM-CSF injection could only maintain for 48 hrs. In addition, the loss in body weight caused by cytoxan was less in the mice with subsequent hGM-CSF than those without CSF. These results suggest that injection of GM-CSF can effectively reconstitute the cytotoxic drug-damaged myelopoiesis without apparent in vivo toxic reaction.

Animals↗
PubMed1991

Quantitative and morphological changes of Langerhans cells in Bowen's disease from patients with chronic arsenicism.

Langerhans cells (LCs) are considered to be responsible for the immunologic presentation of tumor-associated antigens and play a role in the elimination of neoplastic clones. Ultraviolet light B can cause dysfunction and loss of LCs. Both the number and dendritic morphology of LCs are known to be diminished in squamous cell carcinomas from sun-exposed skin. The effects of arsenics on LCs are unknown. Using an OKT-6 monoclonal antibody to stain intraepithelial LCs, we compared their number and morphology in Bowen's lesions and in the perilesional skin from sun-protected sites in ten patients with chronic arsenicism. There was a significant reduction in the numbers of LCs in the Bowen's lesions as compared to the perilesional skin specimens. Loss of dendrites was observed in all Bowen's lesions and in seven of the perilesional skin specimens. Ultrastructurally, the LCs showed an absence of dendrites, but the Birbeck granules were preserved. Since the specimens were not from sun-exposed skin in our study, the findings may be related to chronic arsenic intoxication. The morphologic alteration of LCs observed in the perilesional skin further suggests an arsenic-related systemic dysfunction of the LCs, which in turn may contribute to the development of skin cancers in these patients.

Aged↗
PubMed1978

Investigation of hormone-receptor interactions by means of fluorescence labeling.

Fluorescent-labeled hormones can be used to study hormone-receptor interactions by means of fluorescence polarization, visualization by fluorescence microscopy, or separation methods, e.g., dextran-coated charcoal. Subcellular fragments, single cells, and tissue preparations are amenable to study; in this work rat uterine cytosol was used unless otherwise noted. Estrone labeled with fluorescein at position 17 gives 50% inhibition in the radiometric dextran-coated charcoal assay at 8.3 X 10(-7) M as compared to 3.4 and 3.5 X 10(-8) M for diethylstilbestrol and estradiol, respectively. Scatchard plots from fluorescence polarization are hyperbolic and consistent with two classes of binding sites having association constants 5.6 X 10(10) and 6.4 X 10(7) M-1. Binding by high-affinity sites, which were present at about 3 times the concentraion of "specific" sites (radiometric dextran-coated charcoal assay), was abrogated by estradiol or diethylstilbestrol. Kinetic measurements showed that binding sites that can be blocked by excess estradiol or diethylstilbestrol are those that are both slowly associating and slowly dissociating. Staining of tissues by estrone labeled with fluorescein at position 17 as seen in the fluorescence microscope showed specificity. In normal rat uterus only epithelial cells were stained. In one human infiltrating ductal carcinoma only the malignant ductoid elements stained, while in another there was essentially no staining.

Animals↗