Imaging of parapharyngeal space lesions: focus on the prestyloid compartment.
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Adult↗
Biomedical subjects
J H Shin
Publications and source records attributed to J H Shin.
Application of SCAM (substituted cysteine accessibility method) to gap junction intercellular channels.
The pore-lining residues of gap junction channels determine their permeability to ions and small cellular metabolites. These residues can be identified through systematic cysteine substitution and accessibility analysis, commonly known as SCAM (Substituted Cysteine Accessibility Method). However, application of this technique to intercellular channels is more complicated than for their transmembrane counterparts. We have utilized a novel dual-oocyte perfusion device to apply cysteine reagents to the cytoplasmic face of paired, voltage-clamped Xenopus oocytes. In this configuration, a large and irreversible cysteine reagent MBB (maliemidobutyryl biocytin, mw 537) was shown to readily traverse the gap junction pore and induce conductance changes upon reaction of accessible sites. Of the 11 reactive sites identified, 6 were located in M3, where they span the bilayer. They display a periodicity characteristic of the tilted helix that lines the pore in the gap junction structure of Unger et al. (1999). Access to several of the other sites was attributed to aqueous crevices between transmembrane helices. Reactive sites were slightly different than those identified for gap junction hemichannels (Zhou et al. 1997), suggesting that conformational changes occur upon docking.
Amino Acid Sequence↗
Parapharyngeal second branchial cyst manifesting as cranial nerve palsies: MR findings.
SUMMARY: We report the MR findings of parapharyngeal branchial cleft cyst manifesting as multiple, lower cranial nerve palsies in a 35-year-old woman. On MR images, a well-marginated cystic mass was detected in the right parapharyngeal space, with displacement of both the right internal carotid artery and the right internal jugular vein on the posterolateral side. The cyst contained a whitish fluid that was slightly hyperintense on T1-weighted images and slightly hypointense to CSF on T2-weighted images. No enhancement on contrast-enhanced T1-weighted images was present. The right side of the tongue showed high signal intensity on T2-weighted images, suggesting denervation.
Adult↗
Spinal epidural extraskeletal Ewing sarcoma: MR findings in two cases.
SUMMARY: We report the CT myelography and MR findings of two cases of extraskeletal Ewing sarcoma involving the spinal epidural and paravertebral spaces in a middle-aged man (case 1) and a young woman (case 2). In both cases CT myelography showed epidural and paravertebral masses on one side, with widening of the ipsilateral neural foramina at the C5-C6 level in case 1 and at the C7-T1 level in case 2. On MR images, the masses were isointense to muscle on T1-weighted images, hyperintense on T2-weighted images, and showed moderate enhancement on contrast-enhanced T1-weighted images. In one case, all pulse sequences showed linear signal voids, representing the vertebral artery encasement within the mass. The intradural component connected with the main mass was detected in the other case.
Adult↗
Renal biopsy in elderly patients: clinicopathological correlation in 117 Korean patients.
AIM: In the elderly with renal disease, the clinical presentations are frequently inconsistent with the pathologic findings. We tried to clarify the differences in pathological findings between the young and the elderly, in Korea and in Western countries, and the usefulness of a percutaneous renal biopsy in the elderly with renal disease. PATIENTS AND METHODS: We analyzed the clinical presentations and spectrums of renal histopathology by reviewing medical records and renal biopsy reports retrospectively in 117 Korean patients aged 60 years or more with renal disease. RESULTS: 85 patients had primary renal disease. The remaining 32 patients had renal diseases associated with systemic conditions. Out of the 85 patients with primary renal disease, 61 cases presented as idiopathic nephrotic syndrome. Compared with renal biopsy results of younger adult patients (age 15-59, n = 1,908), membranous nephropathy, crescentic glomerulonephritis, membranoproliferative glomerulonephritis, amyloidosis, light chain disease, and thrombotic thrombocytopenic purpura were more prevalent, but IgA nephropathy and lupus nephritis were less common in the elderly patients. In clinical presentation, nephrotic syndrome and rapidly progressive renal failure were more prevalent, but asymptomatic urinary abnormality was less common in elderly patients. The responsiveness to treatment was good in elderly patients with minimal-change lesion (complete remission in all patients) but poor in crescentic glomerulonephritis, IgA nephropathy, and membranoproliferative glomerulonephritis. From the above findings, the clinical presentation, patterns of histopathology and responsiveness to treatment of elderly Korean patients were similar to those of the younger Korean control group and the Western elderly group. CONCLUSION: Percutaneous renal biopsy is a useful diagnostic aid and can be used as a therapeutic guideline even in elderly patients with renal disease.
Aged↗
T-butyl hydrogen peroxide increases the activities of the Maxi-K channels of rat brain.
In this study, we investigated the effects of tertiary-butyl hydrogen peroxide (tBHP) on the large-conductance Ca2+-activated K+ (Maxi-K) channel of rat brain using lipid bilayer. When tBHP was applied to the cytosolic side, the open probability (Po) of both fast- and slow-gating Maxi-K channels increased within 1 min in dose-dependent manner. tBHP effects did not reverse immediately, suggesting tBHP induces some chemical modification on the channel protein. From kinetic analysis of single channel data, the increase in the Po appears to be mainly due to shortening of closed dwell time in both types of the Maxi-K channels. 50 microM diamide, a sulfhydryl-specific oxidant, irreversibly decreased the Po. However, further addition of 7.3 mM tBHP still increased the Po, suggesting that tBHP does not share the target for oxidation with diamide.
Animals↗
A planar pCO2 sensor with enhanced electrochemical properties.
To develop planar microchemical pCO2 sensing devices with improved electrochemical properties, we combined two advanced technologies. One is a differential sensor arrangement to simplify the microfabrication procedure by employing pH-sensitive gas-permeable membranes, and the other is the use of an enzyme (carbonic anhydrase) to shorten total measurement time by accelerating the rate of CO2 hydration. The adhesion of the polyurethane-matrix gas-permeable membrane is enhanced significantly by incorporating a silanizing reagent (silicon tetrachloride), improving the stability and extending sensor lifetime. The proposed differential pCO2 microelectrodes exhibited significantly improved performance in their preconditioning period, response and recovery times, stability, response slope, and lifetime.
Biosensing Techniques↗
Synthesis of tetrakis(multifluoro-4-pyridyl)porphin derivatives as acetylcholinesterase inhibitors.
New tetrakis(multifluoro-4-pyridyl)porphin derivatives (2-4) and water soluble porphyrin (5) were synthesized to investigate their interactions with acetylcholinesterase from electric eel. These compounds have been found to be the potent reversible inhibitors of the enzyme with Ki values of microM range. In addition, porphyrin (5) showed broad spectrum of anticancer activities.
Animals↗
Kinetics and inhibition of cyclomaltodextrinase from alkalophilic Bacillus sp. I-5.
The cyclomaltodextrinase from alkalophilic Bacillus sp. I-5 (CDase I-5) was expressed in Escherichia coli and the purified enzyme was used for characterization of the enzyme action. The hydrolysis products were monitored by both HPLC and high-performance ion chromatography analysis that enable the kinetic analysis of the cyclomaltodextrin (CD)-degrading reaction. Analysis of the kinetics of cyclomaltodextrin hydrolysis by CDase I-5 indicated that ring-opening of the cyclomaltodextrin was the major limiting step and that CDase I-5 preferentially degraded the linear maltodextrin chain by removing the maltose unit. The substrate binding affinity of the enzyme was almost same for those of cyclomaltodextrins while the rate of ring-opening was the fastest for cyclomaltoheptaose. Acarbose and methyl 6-amino-6-deoxy-alpha-d-glucopyranoside were relatively strong competitive inhibitors with K(i) values of 1.24 x 10(-3) and 8.44 x 10(-1) mM, respectively. Both inhibitors are likely to inhibit the ring-opening step of the CD degradation reaction.
Acarbose↗
Production and characterization of biologically active human GM-CSF secreted by genetically modified plant cells.
Human granulocyte-macrophage colony-stimulating factor (GM-CSF), a hemopoietic growth factor, was produced and secreted from tobacco cell suspensions. The GM-CSF cDNA was carried by a binary vector under the control of the CaMV 35S promoter and the T7 terminator. In addition, a 5'-nontranslated region from the tobacco etch virus (TEV leader sequence) was fused to the N-terminal end of the GM-CSF transgene. For ease of purification, a 6-His tag was added to the 3' end of the GM-CSF cDNA. Addition of the TEV leader sequence increased protein production more than twofold compared to non-TEV controls. Initial batch cultivation studies indicated a maximum of 250 microg/L extracellular and 150 microg/L intracellular GM-CSF. Western blot analysis detected multiple peptides with masses from 14 to 30 kDa in the extracellular medium. The plant-produced GM-CSF was biologically active and could be bound to a nickel affinity matrix, indicating that both the receptor-binding region and the 6-His tag were functional. The batch production of GM-CSF was compared with the production of other recombinant proteins secreted by transformed tobacco cells. The recovery of secreted GM-CSF was increased by the addition of stabilizing proteins and by increasing salt in the growth medium to physiological levels.
Blotting, Northern↗
An arachnoid granulation in the straight sinus.
We report CT, MRI and angiographic findings of an arachnoid granulation in the straight sinus in a young man. Its density and signal intensity were isodense and isointense with cerebrospinal fluid on CT and MRI, respectively. The lesion appeared as a filling defect on MR venography and conventional angiography.
Adult↗
Nosocomial cluster of Candida lipolytica fungemia in pediatric patients.
Candida lipolytica has rarely been reported as a human pathogen. An apparent outbreak of Candida lipolytica fungemia (n = 5 cases) occurred in a pediatric ward over a 9-week period. The five patients infected were hospitalized in three adjacent rooms and cared for by the same healthcare workers. The index patient had central venous catheter-related fungemia, whereas the second patient, who was in the adjacent single room, had transient fungemia. Three additional cases of fungemia occurred in patients with hematological disorders who shared the same room; all three patients had central venous catheters and had been receiving oral fluconazole prophylaxis (50 mg/day for more than 3 weeks) at the time of infection. In vitro susceptibility testing of the strains showed that the MIC of fluconazole for all the isolates was 32 microg/ml. Random amplified polymorphic DNA analysis provided evidence of the clonal origin of the isolates, but the source of the outbreak was not identified. All four patients with persistent fungemia were successfully treated via catheter removal or empiric amphotericin B treatment. This outbreak shows the potential for the nosocomial epidemic transmission of Candida lipolytica.
Adolescent↗
Novel mutations of the PKD1 gene in Korean patients with autosomal dominant polycystic kidney disease.
The gene for the most common form of autosomal dominant polycystic kidney disease (ADPKD), PKD1, has recently been characterized and shown to encode an integral membrane protein, polycystin-1, which is involved in cell-cell and cell-matrix interactions. Until now, approximately 30 mutations of the 3' single copy region of the PKD1 gene have been reported in European and American populations. However, there is no report of mutations in Asian populations. Using the polymerase chain reaction and single-strand conformation polymorphism (SSCP) analysis, 91 Korean patients with ADPKD were screened for mutation in the 3' single copy region of the PKD1 gene. As a result, we have identified and characterized six mutations: three frameshift mutations (11548del8bp, 11674insG and 12722delT), a nonsense mutation (Q4010X), and two missense mutations (R3752W and D3814N). Five mutations except for Q4010X are reported here for the first time. Our findings also indicate that many different mutations are likely to be responsible for ADPKD in the Korean population. The detection of additional disease-causing PKD1 mutations will help in identifying the location of the important functional regions of polycystin-1 and help us to better understand the pathophysiology of ADPKD.
Frameshift Mutation↗
Aroma-active compounds of miniature beefsteakplant (Mosla dianthera Maxim).
Volatile flavor compounds of miniature beefsteakplant (Mosla dianthera Maxim.) from Vietnam were analyzed through gas chromatography-mass spectrometry-olfactometry (GC-MS-O). Sixty-two compounds were identified by GC-MS. Of these, (+/-)-carvone and (+/-)-limonene were the most abundant, followed by (Z)-limonene oxide, beta-caryophyllene, and alpha-humulene. Twenty aroma-active compounds were detected by aroma extract dilution analysis conducted on two GC columns of different polarities (DB-5MS and DB-Wax). The most intense aroma-active compounds were linalool (floral/sweet/lemon), (-)-carvone (spearminty), and 1-octen-3-one (mushroom/earthy). Other predominant aroma-active compounds included (Z)-3-hexenol (grassy/leafy/metallic), (Z)-limonene oxide (lemon/floral), myrcene (plastic/sweet), (+)-limonene (orange/lemon), alpha-thujene (soy sauce/grassy), and (Z)-dihydrocarvone (spearminty/pepperminty). On the basis of the aroma characteristics and intensity, it was concluded that (-)-carvone was responsible for the characteristic aroma of miniature beefsteakplant.
Gas Chromatography-Mass Spectrometry↗
Psoralen-ultraviolet A-induced erythema: sensitivity correlates with the concentrations of psoralen in suction blister fluid.
Since the advent of psoralen-ultraviolet A (PUVA) therapy, the value of plasma 8-methoxypsoralen (8-MOP) concentrations to predict PUVA-induced erythema has been widely investigated. Plasma 8-MOP concentrations have not been proportional to, and cannot alone predict, the degree of PUVA-induced erythema. We assumed that PUVA-induced erythema was related more closely to psoralen concentrations in the skin tissue rather than those within blood vessels. This study was designed to investigate the correlations between the 8-MOP concentrations in suction blister fluid (SBF) and in plasma, with the degree of PUVA-induced erythema. 8-MOP concentrations in plasma and SBF were measured in 15 vitiligo patients and 11 volunteers. Blood and SBF samples were collected 2 h after taking 8-MOP, and 8-MOP concentrations in plasma and SBF were quantified using reverse-phase high-performance liquid chromatography. Eleven volunteers were phototested using a series of doses of ultraviolet A at the time of sampling. The erythema responses were estimated visually to determine the minimal phototoxic dose (MPD). SBF 8-MOP concentrations showed a weak positive correlation with plasma 8-MOP concentrations, which means that we could not predict the exact SBF 8-MOP concentrations using the plasma 8-MOP concentrations. The MPD showed a better correlation with the log of the SBF 8-MOP concentration than with that of the plasma 8-MOP concentration. These results show that plasma 8-MOP concentration cannot represent the exact SBF 8-MOP concentration, and that SBF 8-MOP concentrations, which are representative of the skin tissue 8-MOP level, are more closely related to the erythemal sensitivity during PUVA therapy.
Adolescent↗
Degeneration of the acetabular cartilage in osteonecrosis of the femoral head: histopathologic examination of 15 hips.
Acetabular cartilage with subchondral bone was taken from the superior dome from 15 hips of 13 patients undergoing total hip arthroplasty due to osteonecrosis of the femoral head. The mean age of the patients was 40 years. There were 10 hips ARCO stage IIIA, and 5 hips stage IIIB. 3 of the cases were mild, 12 moderate, and 1 had severe arthrosis. The degree of collapse of the femoral head was significantly related to the degeneration of the acetabular cartilage on histological examination. Our observations support the view that patients with an ARCO Stage III hip do not benefit from head-preserving procedures. They may also explain why bipolar prosthesis gives poorer results than total hip arthroplasty, in cases of osteonecrosis of the femoral head.
Acetabulum↗
Spontaneously infected cephalohematoma: case report and review of the literature.
Spontaneously infected cephalohematomas are rare occurrences; only five cases have been reported previously. Uninfected cephalohematomas are common and usually resolve without treatment. However, physicians should be aware that cephalohematomas are potential sites for infection and may require aspiration for diagnosis and treatment. Untreated infected cephalohematomas may lead to osteomyelitis, epidural abscess, or subdural empyema. We present a case of a spontaneously infected cephalohematoma with an associated osteomyelitis which was successfully managed with drainage and long-term antibiotics. A review of the literature is also presented.
Anti-Bacterial Agents↗
Acute cerebral phaeohyphomycosis due to Wangiella dermatitidis accompanied by cerebrospinal fluid eosinophilia.
We report a case of cerebral phaeohyphomycosis due to Wangiella dermaitidis in an immunocompetent adult man. His cerebrospinal fluid (CSF) showed pleocytosis with a high eosinophil count but without peripheral blood eosinophilia. The present case suggested that this black yeast-like fungus should be included when the causes of CSF eosinophilia are considered, even though it is an extremely rare pathogen.
Adult↗