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Biomedical subjects

E H Choi

Publications and source records attributed to E H Choi.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1998

Clinical outcome of invasive infections by penicillin-resistant Streptococcus pneumoniae in Korean children.

One hundred six cases of invasive pneumococcal infections diagnosed from 1985 to 1996 were analyzed retrospectively. The types of infection were bacteremia without focus (45%), meningitis (19%), peritonitis (17%), pneumonia (bacteremic) (16%), and others (3%). Penicillin-nonsusceptible Streptococcus pneumoniae was first detected in 1989, and its incidence increased rapidly thereafter, reaching 89% in 1995. Initial empirical regimens were of parenteral beta-lactam antimicrobials with or without an aminoglycoside, but these were modified subsequently. Among the 72 nonmeningeal infections analyzed, a favorable response at 72 hours and death were observed in 83% and 2.5%, respectively, of 40 penicillin-susceptible infections, as compared with 86% (P = 1.0) and 7.1% (P = .45) of 14 infections due to intermediate strains and 61% (P = .07) and 11% (P = .22) of 18 due to resistant strains. The favorable-response rate and mortality among 49 patients not in initially critical condition were 92% and zero, respectively, as compared with 52% (P = .00027) and 17% (P = .008) of 23 in critical condition. The data suggest that clinical outcome of penicillin-nonsusceptible pneumococcal infection outside the CNS may be more closely related to clinical condition at presentation than to the level of resistance of the causative strain when such infection is treated with parenteral beta-lactams.

Adolescent↗
PubMed1997

Nevus spilus (speckled lentiginous nevus) associated with a nodular neurotized nevus.

We report a case of nevus spilus with neurotized nevus studied by immunohistochemical methods using S-100, leu-6, glial fibrillary acid protein (GFAP), and myelin basic protein (MBP). Histologic findings of the speckled lesion showed irregular rete ridge elongation, increased epidermal melanocytes and melanin in the epidermis, and scattered nevus cell nests in the upper dermis, but showed neurotized nevus in the deep dermis, which has many features of neurofibroma. Diffuse expression of S-100 protein and MBP, focal staining with GFAP, and lack of staining with leu-7 were observed, Leu-7, positive only in neurofibromas and not in neurotized nevus, appears to be the more pertinent method for distinguishing neurotized nevus from neurofibroma.

CD57 Antigens↗
PubMed1997

'Swiss cheese' lymphangiectasia in a case of solitary morphea profunda.

Reports of lymphangiectases that occur in lesions of morphea are rare. We describe a 24-year-old woman with a solitary morphea profunda associated with lymphangiectasia. Unlike previously reported cases, our case showed lymphatic dilatation resembling Swiss cheese and developed around a milium.

Adult↗
PubMed1997

The changes of stratum corneum interstices and calcium distribution of follicular epithelium of experimentally induced comedones (EIC) by oleic acid.

Abnormal follicular keratinization is important for comedo formation in acne, but the precise mechanism is not known. A recent report about acne vulgaris suggested that an impaired water barrier function may be responsible for comedo formation, since the barrier dysfunction is accompanied by hyperkeratosis of the follicular epithelium. Furthermore, the integrity of the water barrier is crucial for the maintenance of the epidermal calcium gradient. Yet stratum corneum intercellular lipid structures, a major factor of the skin barrier function, and calcium distribution in the follicular epithelium of comedones, were not reported. To see SC intercellular lipid and calcium distribution of the follicular epithelium of comedo by electron microscopy, we applied oleic acid on the inner surface of the ear of New Zealand white rabbits to induce comedones, and then we obtained specimens and performed osmium and ruthenium tetroxide postfixation and calcium ion-capture cytochemical procedure. We found incomplete lipid bilayer structures, prominent dilatation of lacunar domains and the loss of follicular epidermal calcium gradient in experimentally induced comedones. From our results, we suggest that the permeability barrier disruption in oleic-acid-applied follicular epithelium can be induced by the changes of SC intercellular membrane structures and lacunar dilatation, and the calcium gradient is lost, so follicular epithelial proliferation and hyperkeratosis can be induced and then comedo formation occurs.

Acne Vulgaris↗
PubMed1997

Secondary penile carcinoma originated from pancreas.

Secondary penile cancers are rarely seen and most of them are originated from genitourinary and gastrointestinal tract. But metastatic penile cancer originated from pancreas are extremely rare and two cases have been reported in the literature, only one of them was pathological proven in autopsy. We report a case of secondary penile carcinoma originated from the pancreas as the primary site which was pathologically proven.

Adenocarcinoma↗
PubMed1997

Epidemiological and clinical features of Behçet's disease in Korea.

Behçet's disease occurs with a high prevalence in the Far East including Korea. In this report we inspected 1,155 patients with Behçet's disease and collected information concerning the clinical and epidemiologic features of Behçet's disease in Korea. In summary, patients in their 30s were the most common, with the most common age of onset in the 20s; the sex ratio was 0.63:1 with female predominance; according to revised Shimizu's classification, the order of frequency of the different types was incomplete (38.2%), suspected (25.4%), possible (20.3%) and complete (16.1%); oral ulcers were the most frequent major symptom (97.5%) and the most common initial symptom (78.5%); erythema nodosum-like lesion (55.3%) was the most common type of skin lesion; a seasonal aggravation of the disease was observed in 21.3% of patients; and the most common type of childhood onset Behçet's disease was suspected type.

Adolescent↗
PubMed1996

Hybrid cysts showing alternate combination of eruptive vellus hair cyst, steatocystoma multiplex, and epidermoid cyst, and an association among the three conditions.

Eruptive vellus hair cyst (EVHC), steatocystoma multiplex (SM), and epidermoid cyst are characterized by formation of multiple cutaneous cysts and have a resemblance in clinical features but have distinctive histologic features. We present herein two patients, who had EVHC, SM, and EVHC with sebaceous gland, and who also had EVHC, SM, and epidermoid cyst with sebaceous gland and vellus hairs. In addition, the interrelation among the three diseases is discussed. We think that EVHC, SM and epidermoid cyst are within the same spectrum of the disease process.

Adult↗
PubMed1996

Unusual cases of syringoma of the forehead.

Syringoma involving the forehead is rare and can be confused with other diseases that are common on the forehead. Therefore, we describe here three patients with syringoma who developed numerous skin colored papules on the forehead. To our knowledge, syringoma of the forehead was reported previously only once by Tagami et al.

Adult↗
PubMed1996

Piebaldism--a case report.

We report a familial case of piebaldism affecting a 33-year-old man and his 3-month-old son. Typical skin findings, white forelock and amelanotic white macules containing hyperpigmented macules, were characteristically presented on both patients.

Adult↗
PubMed1996

Perforating plate-like osteoma cutis in a man with solitary morphoea profunda.

Solitary morphoea profunda is an unusual form of scleroderma, characterized by marked fibrosis, hyalinization of collagen fibres, and inflammatory cell infiltration in the deep dermal and subcutaneous layers. We describe a 58-year-old man showing solitary morphoea profunda. Plate-like osteoma cutis, with transepidermal elimination of bony material, within the morphoea profunda, was present.

Humans↗
PubMed1996

Congenital cartilaginous rests of the neck.

We describe a case of congenital cartilaginous rests of the neck arising on the suprasternal midline area of the neck in a Korean infant. The lesion was characterized by discrete nodules of mature elastic cartilage in the lower dermis or superficial subcutaneous soft tissue and multiple vellus hair follicles in the overlying skin.

Biopsy, Needle↗