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Biomedical subjects

S K Seo

Publications and source records attributed to S K Seo.

10 recordsLinked to original sources
PubMed2005

A multidisciplinary approach to antimicrobial stewardship: evolution into the 21st century.

In the 21st century, we face the problems of escalating antibiotic resistance, difficult-to-treat infections and slowed new drug development. Healthcare practitioners are increasingly recognising the importance of good antimicrobial stewardship. Various strategies such as formulary management, prior approval, clinical pathways, post-prescribing evaluation and intravenous to oral conversion have been used singly or in combination to improve prescribing and reduce costs. Combining a multifaceted approach with a full-time dedicated multidisciplinary team appears to be capable of yielding satisfactory clinical and economic outcomes and most importantly, sustaining efforts of antimicrobial stewardship. The multidisciplinary approach to antibiotic management should be tailored to fit the individual needs of an institution. More data are needed to document effects on curbing resistance.

Anti-Bacterial Agents↗
PubMed2001

Cytomegalovirus ventriculoencephalitis in a bone marrow transplant recipient receiving antiviral maintenance: clinical and molecular evidence of drug resistance.

We describe a case of CMV ventriculoencephalitis in a severely immunocompromised bone marrow transplant recipient who was receiving combination therapy with ganciclovir and foscarnet for treatment of viremia and retinitis. Analysis of sequential viral isolates recovered from the patient's cerebrospinal fluid suggested that disease developed because of the presence of viral resistance and, possibly, low tissue penetration of antiviral agents.

Antiviral Agents↗
PubMed2001

Murine keratocytes function as antigen-presenting cells.

Keratocytes express MHC class I molecules constitutively, and keratocytes stimulated with IFN-gamma express MHC class II molecules. Unstimulated keratocytes constitutively express B7-1 and ICAM-1, as well as low levels of CD40 and 4-1BBL. These findings indicate that keratocytes may deliver both antigen-specific and costimulatory signals to CD4(+) and CD8(+) T cells. To demonstrate that keratocytes expressing B7-1 provide a costimulatory signal to T cells, CD4(+) or CD8(+) mouse T cells were incubated with anti-CD3 mAb and irradiated keratocytes. Enhanced proliferation of both CD4(+) and CD8(+) T cells occurred, and could be inhibited by anti-B7-1 mAb, indicating T cell costimulatory activity by B7-1 on the keratocytes. To demonstrate that keratocytes can deliver an antigen-specific signal, CD4(+) and CD8(+) T cells from herpes-infected mice were incubated with HSV-1-infected, irradiated keratocytes. The resulting T cell proliferation and production of Th1 cytokines (IL-2, IFN-gamma) indicated T cell activation by antigens presented by the infected keratocytes. These results show that keratocytes in the corneal stroma of the mouse can function as antigen-presenting cells and, thus, may play a role in immune-mediated stromal inflammation such as herpetic stromal keratitis.

Animals↗
PubMed2000

Molecular typing of coagulase-negative staphylococci from blood cultures does not correlate with clinical criteria for true bacteremia.

PURPOSE: Determining whether a blood culture that contains coagulase-negative staphylococci represents bacteremia or contamination is a clinical dilemma. We compared molecular-typing results of coagulase-negative staphylococcal blood culture isolates with clinical criteria for true bacteremia. SUBJECTS AND METHODS: Pulsed-field gel electrophoresis and arbitrary primed polymerase chain reaction (PCR) were used to determine whether patients with two or more blood cultures with coagulase-negative staphylococcal isolates had the same strain of organism in each culture (same strain bacteremia). We evaluated three different clinical criteria for bacteremia: whether the patient received more than 4 days of antibiotics, whether there was an explicit note in the medical chart in which the physician diagnosed a true bacteremia, and the Centers for Disease Control surveillance criteria for primary bloodstream infection. Agreement between same-strain bacteremia and each definition was examined, based on the assumption that most true infections should be the result of a single strain. RESULTS: The study sample consisted of 42 patients and 106 isolates. Nineteen of the 42 bacteremias (45%) were the same strain. Classification of bacteremias as same-strain correlated poorly with all three clinical assessments (range of percent agreement, 50% to 57%; range of kappa statistic, 0.01 to 0.15). There were both false-positive and false-negative errors. Patients with three or more positive blood cultures were more likely to have same-strain bacteremia than those with only two positive cultures [11 of 15 (73%) vs 8 of 27 (30%), P = 0.006]. Pulsed-field gel electrophoresis was more discriminating than arbitrary primed PCR (percent agreement, 83%; kappa, 0.67). CONCLUSION: Molecular typing correlated poorly with clinical criteria for true bacteremia, suggesting either that true bacteremias are frequently the result of multiple strains or that the commonly used clinical criteria are not accurate for distinguishing contamination from true bacteremia. Vancomycin treatment of clinically defined coagulase-negative staphylococcal bacteremia may frequently be unnecessary.

Bacteremia↗
PubMed2000

4-1BB: still in the midst of darkness.

4-1BB is a member of the tumor necrosis factor receptor superfamily. The receptor functions mainly as a costimulatory molecule in T lymphocytes. In addition, several lines of evidence have shown that interactions between 4-1BB and its ligand are involved in the antigen presentation process and the generation of cytotoxic T cells. Recent studies, however, have demonstrated that 4-1BB plays more diverse roles: Signals through 4-1BB are important for long-term survival of CD8+ T cells and the induction of helper T cell anergy. Clinically, there is great interest in 4-1BB, because T-cell activation induced by anti-4-1BB monoclonal antibodies is highly efficient in the eradication of established tumor cells in mice. Now, since mice deficient in 4-1BB or the 4-1BB ligand are available, subtle roles played by 4-1BB may be revealed in the near future.

4-1BB Ligand↗
PubMed1999

Regulation and inactivation of brain phosphocholine-phosphatase activity.

Regulation of phosphocholine-hydrolyzing phosphatase (phosphocholine-phosphatase) activity, purified from bovine brain, was examined under physiological conditions. Various endogenous phosphomonoesters, which were utilized as substrate, inhibited the phosphocholine-phosphatase activity competitively (Ki, 5.5-82.0 microM); among phosphomonoesters tested, there was a similar order of capability between the binding affinity of substrate and the inhibitory potency. In addition, phosphate ions also inhibited the phosphatase activity competitively with a Ki value of approximately 167 microM. Although leucine or theophylline inhibited the phosphatase activity at pH 9.0, their inhibitory action decreased greatly at pH 7.4. The pH-Km and pH-Vm profiles indicate that ionizable amino acids are involved in substrate binding as well as catalysis, alluding that the phosphatase activity may be highly dependent on the intracellular pH. Amino acid modification study supports the existence of tyrosine, arginine or lysine residue in the active site, and the participation of tyrosine residue in the catalytic action may be suggested positively from the susceptibiliy to the action of tetranitromethane or HOI-generator. Separately, the oxidative inactivation of phosphocholine-phosphatase activity was investigated. Of oxidants tested, HOONO, HOCl, HOI and ascorbate/Cu2+ system were effective to inactivate the phosphatase activity. Noteworthy, a remarkable inactivation was accomplished by 30 microM HOCl in combination with 1 mM KI. In addition, Cu2+ (3 microM) in combination with ascorbate at concentrations as low as 0.1-0.3 mM reduced the phosphatase activity to a great extent. From these results, it is proposed that the phosphocholine-phosphatase activity may be regulated endogenously and susceptible to the various oxidant systems in vivo.

Amino Acids↗
PubMed1998

Single hair grafting for the treatment of vitiligo.

BACKGROUND: Vitiligo is a disease of unknown cause, and many medical and surgical therapeutic methods are used to treat it. OBJECTIVE: Our purpose was to evaluate the effectiveness of single hair grafting in patients with vitiligo. METHODS: Single hairs were grafted into vitiliginous areas of 21 patients. The diameter of the spreading pigmentation was evaluated periodically. RESULTS: Perifollicular repigmentation around the grafted hair was observed in 15 patients (71%) within 2 to 8 weeks. The diameter of the spreading pigmentation ranged from 2 to 10 mm during a 12-month follow-up period. In cases of generalized vitiligo, perifollicular pigmentation was seen in one of four patients (25%), whereas it was observed in 14 of 17 patients (82%) with localized/segmental vitiligo. Transformation of depigmented hairs into pigmented ones occurred in five patients. CONCLUSION: Single hair grafting appears to be an effective method for treating localized/segmental vitiligo, especially on hairy parts of the skin, including the eyelids and eyebrows, and for small areas of vitiligo.

Adult↗
PubMedDate not supplied

Kasabach-Merritt syndrome: identification of platelet trapping in a tufted angioma by immunohistochemistry technique using monoclonal antibody to CD61.

Kasabach-Merritt syndrome (KMS) consists of large and rapidly growing vascular tumors associated with thrombocytopenia, generalized petechiae, and bleeding. The cause of the thrombocytopenia is thought to be related to the trapping of platelets by the abnormal endothelium of the tumor. We report an infant with KMS that developed in association with a large tufted angioma. In this case we directly demonstrated platelet trapping in the vascular lumen of the tumor by an immunohistochemical technique using a monoclonal antibody against CD61, a marker of platelets and megakaryocytes.

Antibodies, Monoclonal↗
PubMedDate not supplied

Lichenoid sarcoidosis in a 3-year-old girl.

We report a case of lichenoid sarcoidosis in a 3-year-old girl. She had numerous discrete skin-colored or erythematous, infiltrated follicular papules on the buttocks and extremities since 2 months of age. Histopathologic examination showed follicular plugging and an upper dermal granulomatous infiltrate of epithelioid cells closely surrounding the follicular ducts. No acid-fast bacilli were seen in the sections examined. Chest radiograph and high-resolution computed tomography (CT) showed no hilar lymphadenopathy or pulmonary parenchymal changes. An angiotensin-converting enzyme level was elevated. The Mantoux reaction was negative and results of ophthalmologic examinations were normal. Treatment was started with triamcinolone 0.2 mg/kg and prednicarbate ointment. Some lesions healed completely and others showed residual pitting.

Administration, Topical↗