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Biomedical subjects

S K Ahn

Publications and source records attributed to S K Ahn.

At least 37 records · Page 2Linked to original sources
PubMed1999

Nurse's cap alopecia.

BACKGROUND: Traction alopecia associated with the nurse's cap is a relatively common form of occupational hair loss. METHODS: We examined 199 healthy South Korean nurses to assess the clinical and pathologic characteristics of traction alopecia caused by prolonged traction exerted at the point of attachment of the nurse's cap. RESULTS: Seven nurses (3.5% of 199) had hair loss at the pin site used to secure the nurse's cap. The lesions were exclusively localized on the parieto-occipital scalp. Histopathologic findings revealed characteristic cicatricial changes which showed a marked decrease in the number of hair follicles without inflammation. CONCLUSIONS: Nurse's cap alopecia is not an uncommon occupational alopecia, and appears to be a distinct clinical entity which should be distinguished from other forms of patchy alopecia.

Adult↗
PubMed1999

The changes of epidermal calcium gradient and transitional cells after prolonged occlusion following tape stripping in the murine epidermis.

Disruption of the epidermal permeability barrier causes an immediate loss of the calcium gradient, and barrier recovery is parallel with the restoration of the calcium gradient in the epidermis. Artificial restoration of the barrier function by occlusion with a water vapor-impermeable membrane abrogate the expected increase in lipid synthesis and retard the barrier recovery, as well as block the normalization of the epidermal calcium gradient. To clarify the long-term effects of occlusion after acute barrier perturbation, we studied the calcium distribution and epidermal keratinocytes response after occlusion with a water vapor-impermeable membrane immediately following tape stripping in the murine epidermis. Acute barrier disruption caused an immediate depletion of most calcium ions in the upper epidermis, obliterating the normal calcium gradient. When the skin barrier function was artificially corrected by occlusion, the return of calcium ions to the epidermis was blocked. After 2 h of air exposure or occlusion, the density of epidermal calcium precipitates remained negligible. The transitional cell layers appeared with occlusion, but not or negligibly with air exposure. By 6 h though, calcium precipitates could be seen, the density of the calcium precipitates with occlusion was more sparse than with air exposure. With the air exposure, the thickness of the stratum corneum had normalized and the calcium gradient nearly recovered to normal after 24 h. The longer the occlusion period, the greater was the increase of transitional cells. By 60 h of occlusion, the thickness of the stratum corneum had increased and the transitional cell layers had disappeared, in parallel with the calcium gradient which was almost normalized. These results show that prolonged occlusion of tape-stripped epidermis induced transitional cells and delayed the restoration of the epidermal calcium gradient, the stratum corneum was then restored, transitional cells having disappeared, in parallel with normalization of the epidermal calcium gradient.

Animals↗
PubMed1999

Chronic pruritic papular dermatitis in adult men: a variant of prurigo.

Chronic recurrent pruritic papular eruptions in which a specific diagnosis cannot be established becomes a baffling experience to the dermatologist. We have met adult male patients with chronic recurrent pruritic papular eruptions, but their clinicopathological features are not described in English language textbooks. Our purpose was to study the clinical and histological features of this entity and review the various existing taxonomy. We conducted a study of 20 patients over a six year period by taking histories, performing skin biopsies, screening patch tests, and doing immunofluoresence studies. The eruptions occurred exclusively in male adults and had a predilection for the trunk and proximal extremities. The lesions were characterized by severely pruritic, nonfollicular, monomorphic, erythematous urticarial papules. There was no evidence of atopic diathesis or history of insect bite. Most patients had normal levels of serum eosinophils and IgE. The predominant histopathologic finding was a presence of perivascular infiltration of mononuclear cells with eosinophils. The patients followed a chronic course of at least six months with waxing and waning; systemic corticosteroids were the only effective treatment. Finally, all other pruritic erythematous papular dermatoses were ruled out. These cases comprise a distinct entity that has previously been mentioned in a few reports. Clear definition of this entity with an appropriate designation is in order to avoid confusion among dermatologists, and we propose the disease name "chronic papular dermatitis in adult men" as a variant of prurigo.

Adrenal Cortex Hormones↗
PubMed1999

A case of pre-Sézary syndrome preceded by hand lesions.

Pre-Sézary syndrome is an erythroderma with a chronic course, clinical findings of Sézary syndrome, lymphocytic subepidermal band infiltration at times, and repeated cycles of circulating Sézary cells of less than 1,000 cells/mm3. Duration of the pre-existing skin diseases preceding pre-Sézary erythroderma varies from a few weeks to 20 years. Before the erythroderma develops, these patients are diagnosed with contact dermatitis, neurodermatitis, chronic dermatitis, atopic dermatitis, or asteatotic eczema. Hand lesion also precedes the pre-Sézary erythroderma. This condition has been controlled by three cycles of chemotherapy consisting of vincristine, cytoxan, doxorubicin, and prednisolone. We describe a case of pre-Sézary syndrome preceded by hand lesion and treated with chemotherapy.

Adult↗
PubMed1999

A case of perineal schwannoma resembling a skin tag.

We describe a case of perineal schwannoma (neurilemmoma) that resembled a skin tag. The structure was composed of a 1.5 cm x 1.4 cm x 1 cm sized mass and a movable stalk. After excision of the mass from the stalky root with scissors, H & E staining of the specimen revealed an encapsulated intradermal mass composed of Antoni-A type and Antoni-B type tissue.

Adult↗
PubMed1999

Vascular tumors arising in port-wine stains: two cases of pyogenic granuloma and a case of acquired tufted angioma.

Three female patients affected by intradermal vascular tumors were presented. The lesions were acquired and developed from preexisting port-wine stains (PWS). Among the three patients observed, two had a pyogenic granuloma (PG) and the third patients had tufted angiomas. As reported earlier, formation of a PG within the lesion of a PWS supports the assumption that arteriovenous anastomoses are associated with its pathogenesis. Occurrence of tufted angioma from a PWS, as well as coexisting but separate PWS has been reported. However, the tufted angiomas of our patient were located in different sites, one in the PWS and others separate from the PWS. This has never previously been reported.

Adult↗
PubMed1999

Serologically diagnosed Lyme disease manifesting erythema migrans in Korea.

Lyme disease is a vector-borne infection, primarily transmitted by Ixodes ticks, and caused by Borrelia burgdorferi. It has a wide distribution in the northern hemisphere. In Korea, however, only one human case has been reported, although B. burgdorferi was isolated from the vector tick I. persulcatus in the region. A 60-year-old male and a 45-year-old female developed the clinical sign of erythema migrans. Each patients were bitten by a tick four weeks and five weeks, respectively, before entering the hospital. On serologic examination, significantly increased IgM and IgG antibody titers to B. burgdorferi were observed in consecutive tests performed at an interval of two weeks. They responded well to treatment with tetracycline.

Erythema Chronicum Migrans↗
PubMed1999

Disseminated superficial actinic porokeratosis like drug eruption: a case report.

We report a 54-year-old male patient who developed an unusual form of generalized drug eruption. He had pain and breathlessness on the left chest wall. He had history of taking several drugs at private clinics under a diagnosis of herpes zoster. Two weeks later he had a generalized skin eruption. Examination showed multiple variable sized, mild pruritic, erythematous macules and papules on the face and upper extremities. Skin lesions take the form of a clinically consistent with disseminated superficial actinic porokeratosis (DSAP). Methylprednisolone 16 mg, astemisole 10 mg, oxatomide 60 mg was prescribed. Topical corticosteroid cream was applied. Within two months, his eruption had cleared almost completely. The pathogenetic mechanisms of this case are unclear, but drug and UV light have been considered.

Drug Eruptions↗
PubMed1999

Leukemic macrocheilia associated with chronic lymphocytic leukemia.

Specific cutaneous infiltrates in chronic lymphocytic leukemia presenting as a tumor or a large nodule on the face, scalp, and upper trunk are rare; involvement of the oral mucosa is extremely rare. We report a case of leukemic macrocheilia that occurred three years before a diagnosis of chronic lymphocytic leukemia was made.

Diagnosis, Differential↗
PubMed1999

Acne mechanica due to an orthopedic crutch.

Acne mechanica describes local irritation due to the skin being pressured, occluded, rubbed, squeezed, stretched, or heated. Examples of various physical traumas that provoke lesions in acne patients are given. Users of orthopedic crutches are at particular risk for such conditions. A crutch is another extrinsic factor to be added to the list of causes of acne mechanica.

Acneiform Eruptions↗
PubMed1998

Antitumor activity of 7-[2-(N-isopropylamino)ethyl]-(20S)-camptothecin, CKD602, as a potent DNA topoisomerase I inhibitor.

We developed a novel water-soluble camptothecin analogue, CKD602, and evaluated the inhibition of topoisomerase I and the antitumor activities against mammalian tumor cells and human tumor xenografts. CKD602 was a nanomolar inhibitor of the topoisomerase I enzyme in the cleavable complex assay. CKD602 was found to be 3 times and slightly more potent than topotecan and camptothecin as inhibitors of topoisomerase, respectively. In tumor cell cytotoxicity, CKD602 was more potent than topotecan in 14 out of 26 human cancer cell lines tested, while it was comparable to camptothecin. CKD602 was tested for the in vivo antitumor activity against the human tumor xenograft models. CKD602 was able to induce regression of established HT-29, WIDR and CX-1 colon tumors, LX-1 lung tumor, MX-1 breast tumor and SKOV-3 ovarian tumor as much as 80, 94, 76, 67, 87% and 88%, respectively, with comparable body weight changes to those of topotecan. Also the therapeutic margin (R/Emax: maximum tolerance dose/ED58) of CKD602 was significantly higher than that of topotecan by 4 times. Efficacy was determined at the maximal tolerated dose levels using schedule dependent i.p. administration in mice bearing L1210 leukemia. On a Q4dx4 (every 4 day for 4 doses) schedule, the maximum tolerated dose (MTD) was 25 mg/kg per administration, which caused great weight loss and lethality in < 5% tumor bearing mouse. This schedule brought significant increase in life span (ILS), 212%, with 33% of long-term survivals. The ex vivo antitumor activity of CKD602 was compared with that of topotecan and the mean antitumor index (ATI) values recorded for CKD602 were significantly higher than that noted for topotecan. From these results, CKD602 warrants further clinical investigations as a potent inhibitor of topoisomerase I.

Animals↗
PubMed1998

Urticarial reaction following the inhalation of nicotine in tobacco smoke.

We report a patient with recurrent generalized itching and urticaria due to inhalation of nicotine in tobacco smoke. A skin prick test with nicotine base (1:10 w/v) was negative but an intradermal test with nicotine base (1:100 w/v) was strongly positive. Intradermal tests with nicotine base (1:100 w/v) performed on 10 healthy controls were negative. A provocation test with a nicotine patch showed the same symptoms and signs including generalized itching, weals and flares, and mild dyspnoea, which occurred when he was exposed to tobacco smoke. Nicotine in tobacco smoke can act as an inhalant allergen and induce urticaria in hypersensitive persons.

Administration, Inhalation↗
PubMed1998

AA line.

BACKGROUND: The transverse skin line of the upper part of the forearm is a common, easily recognized condition; however, this line has not been defined clearly and does not correspond to other previously reported skin lines. Our purpose was to assess the nature and associated conditions of this skin line, and characterize the histopathologic features. METHODS: We examined 1343 healthy Korean people. The persons showing this skin line were evaluated by history and physical examination. Skin biopsy was performed on 10 persons showing this line: on one side at both the lesion and contralateral, non-lesion sites. RESULTS: A total of 480 persons (36.4%) showed this line. The incidence was significantly higher in the female group and in the group between 10 and 19 years of age. Histopathologic examination showed subtle edema, separation and fragmentation of collagen bundles, and vasodilation at the transverse skin line. CONCLUSIONS: We conclude that this skin line represents a newly defined skin line, and propose the term AA line.

Adolescent↗
PubMed1998

Iontophoresis itself on hairless mouse skin induces the loss of the epidermal calcium gradient without skin barrier impairment.

Iontophoresis increases the delivery of drugs across the stratum corneum, but the pathway by which ionized drugs transit the stratum corneum is unknown. In this study we examined the effect of iontophoresis on the skin barrier and the epidermal calcium gradient. Hairless mice were subjected to iontophoresis for 5-120 min and skin specimens were prepared for electron microscopy. Neither positive nor negative iontophoresis affected transepidermal water loss. Lacunar dilatation and partial distention of the intercellular layers of the stratum corneum were observed in rough proportion to applied time in iontophoresis skin as well as control skin. Additionally, using calcium capture cytochemistry, we demonstrated that both positive and negative iontophoresis caused the disappearance of the epidermal calcium gradient with marked decrease in calcium content in the upper epidermis. Positive iontophoresis was associated with increased calcium in the stratum basale and dermis, whereas negative iontophoresis increased calcium in the stratum corneum. Moreover, as previously shown after barrier disruption and sonophoresis, the decrease in calcium content in the upper epidermis was associated with an increase in lamellar body secretion and the build up of lamellar material at the stratum corneum-stratum granulosum interface. In conclusion, iontophoresis on the skin of hairless mice may induce the change of ionized molecules in the epidermis, as the loss of the calcium gradient, which causes the decrease of skin impedence, gives charged drugs the ability to cross the skin more easily. Also, the structural changes, such as lacunar dilatation, whether they result from hydration or occlusion, may help the transport of charged drugs across the stratum corneum.

Animals↗