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Biomedical subjects

S M Kim

Publications and source records attributed to S M Kim.

At least 19 recordsLinked to original sources

Comparison of effects of angiotensin peptides in the regulation of clitoral cavernosum smooth muscle tone.

The isometric tension measurement and in vitro autoradiography were used in clitoral cavernosum smooth muscle (CSM). Angiotensin ANG III, ANG IV, ANG II and ANG I induced contractions in clitoral CSM strips. ANG III and ANG I- induced contraction was five times less active than ANG II, whereas ANG IV-induced contraction was 1181-fold less potent than ANG II. Contractile responses to ANG III, ANG IV, ANG II and ANG I were significantly inhibited by type 1 ANG II (AT 1) receptor antagonist Dup 753 but not by type 2 ANG II (AT2) receptor antagonist PD 123,319. Pre-treatment with Nomega-nitro-L-arginine methyl ester, nitric oxide (NO) synthase inhibitor accentuated force of contraction induced by ANG III, ANG IV and ANG II. Amastatin, an aminopeptidase inhibitor enhanced ANG III- and ANG IV-induced contractions. Specific binding sites for 125I-ANG II were found in the clitoral CSM. Specific binding of 125I-ANG II was displaced by unlabeled ANG peptides. This study suggests that the contractile responses to all four peptides of the ANG family are mediated via AT1 receptors but not AT2 receptors. Further, the rank order of potency of contraction was as follows, ANG II> ANG I>ANG III>ANG IV. It is also suggested that peptides of the ANG family have a cross-talk with the NO system and aminopeptidase is involved in the modulation of the tone of clitoral CSM by ANG III and ANG IV.

Acetylcholine↗

Localization of Claude's syndrome.

Although the red nucleus often has been suggested to be the lesion site responsible for Claude's syndrome, the precise localization of the syndrome is uncertain. Lesion sites were reviewed in six patients with Claude's syndrome and compared with other patients with the syndrome identified by a literature search. The findings strongly suggest that Claude's syndrome occurs because of a lesion of the superior cerebellar peduncle just below and medial to the red nucleus. Midbrain infarction and partial oculomotor nerve palsy was common.

Adult↗

Regulation of replication timing in fission yeast.

Here we report the first characterization of replication timing and its regulation in the fission yeast Schizosaccharomyces pombe. We used three different synchronization methods: centrifugal elutriation, cdc10 temperature-shift and release, and starvation for deoxyribonucleoside triphosphates (dNTPs) by treatment with hydroxyurea (HU) followed by removal of HU, to study the times when specific autonomously replicating sequence elements (ARS elements; potential replication origins) replicate during S phase. We found that individual ARS elements replicate at characteristic times, some early and some late, independently of synchronization method. In wild-type cells treated with HU, early ARS elements replicated but late ones did not. However, in HU-treated mutant cells lacking the Rad3 (similar to human ATR and ATM) or Cds1 (similar to human CHK2) checkpoint kinase, both early and late ARS elements were able to replicate. Thus under conditions of dNTP starvation the Rad3 and Cds1 kinases are needed to suppress the replication of normally late-replicating regions.

Adenosine Triphosphatases↗

Diagnostic accuracy and certainty from sequential evaluations in peripheral neuropathy.

Three masked neuromuscular experts analyzed the contribution of the data from sequential evaluations in predicting specific varieties of peripheral neuropathy in 72 patients. The largest improvement (16%) in diagnostic accuracy resulted from presentation of neurologic history. By contrast, diagnostic confidence increased gradually with presentation of additional medical information. Therefore, the authors conclude that for diagnostic accuracy and certainty, expert neuromuscular judgment and extensive characterizing or discriminative testing are needed.

Cohort Studies↗

Improved detection and differentiation of mycobacteria with combination of Mycobacterium Growth Indicator Tube and Roche COBAS AMPLICOR System in conjunction with Duplex PCR.

In this study, a combination of liquid and solid media (current "gold standard" for culture) with combinations of liquid media (Mycobacteria Growth Indicator Tube (MGIT)) plus a commercial amplification system (Roche COBAS AMPLICOR System (CAS)), and solid media (Ogawa) plus CAS for detection of Mycobacterium tuberculosis were compared. In addition, the ability of the MGIT to recover mycobacteria from various clinical samples was compared with the abilities of egg-based Ogawa medium using equal volume of samples and a high concentration (6%) of NaOH for decontamination. A total of 705 specimens (395 respiratory and 310 extrapulmonary) that were collected from 554 patients were tested in parallel with three assays. The results of MGIT and Ogawa were evaluated with the "gold standard" (combination of culture and clinical data) and those of CAS were evaluated with extended gold standard including treated tuberculosis. A total of 130 mycobacterial infections (M. tuberculosis, n=122; mycobacterium other than tuberculosis (MOTT), n=8) were detected. The differentiation of M. tuberculosis and MOTT was successfully accomplished using duplex PCR. The overall sensitivity of the MGIT, Ogawa, and CAS for M. tuberculosis was 89.9%, 73.9%, and 79.9%, respectively. For the MOTT, the corresponding values for the MGIT and Ogawa medium were 100% and 12.5%, respectively. The mean detection time for M. tuberculosis was 22 days using MGIT and 32 days when using the Ogawa medium. The specificity of CAS was 98.4%, with an inhibition rate of 1.4%. A combination of MGIT plus CAS detected 97.5% of all M. tuberculosis infections (compared with MGIT plus Ogawa, 91.8%, P<0.05; compared with Ogawa plus CAS, 87.7%. P<0.01). Our results indicate that a combination of MGIT plus a Roche CAS in conjunction with duplex PCR, would be quite useful in clinical laboratories for both rapid detection and differentiation of M. tuberculosis and MOTT.

Chi-Square Distribution↗

Comparison of control of Listeria by nitric oxide redox chemistry from murine macrophages and NO donors: insights into listeriocidal activity of oxidative and nitrosative stress.

The physiological function of nitric oxide (NO) in the defense against pathogens is multifaceted. The exact chemistry by which NO combats intracellular pathogens such as Listeria monocytogenes is yet unresolved. We examined the effects of NO exposure, either delivered by NO donors or generated in situ within ANA-1 murine macrophages, on L. monocytogenes growth. Production of NO by the two NONOate compounds PAPA/NO (NH2(C3H6)(N[N(O)NO]C3H7) and DEA/NO (Na(C2H5)2N[N(O)NO]) resulted in L. monocytogenes cytostasis with minimal cytotoxicity. Reactive oxygen species generated from xanthine oxidase/hypoxanthine were neither bactericidal nor cytostatic and did not alter the action of NO. L. monocytogenes growth was also suppressed upon internalization into ANA-1 murine macrophages primed with interferon-gamma (INF-gamma) + tumor necrosis factor-alpha (TNF-alpha or INF-gamma + lipid polysaccharide (LPS). Growth suppression correlated with nitrite formation and nitrosation of 2,3-diaminonaphthalene elicited by stimulated murine macrophages. This nitrosative chemistry was not dependent upon nor mediated by interaction with reactive oxygen species (ROS), but resulted solely from NO and intermediates related to nitrosative stress. The role of nitrosation in controlling L. monocytogenes was further examined by monitoring the effects of exposure to NO on an important virulence factor, Listeriolysin O, which was inhibited under nitrosative conditions. These results suggest that nitrosative stress mediated by macrophages is an important component of the immunological arsenal in controlling L. monocytogenes infections.

2-Naphthylamine↗

Multiple redundant sequence elements within the fission yeast ura4 replication origin enhancer.

BACKGROUND: Some origins in eukaryotic chromosomes fire more frequently than others. In the fission yeast, Schizosaccharomyces pombe, the relative firing frequencies of the three origins clustered 4-8 kbp upstream of the ura4 gene are controlled by a replication enhancer - an element that stimulates nearby origins in a relatively position-and orientation-independent fashion. The important sequence motifs within this enhancer were not previously localized. RESULTS: Systematic deletion of consecutive segments of approximately 50, approximately 100 or approximately 150 bp within the enhancer and its adjacent core origin (ars3002) revealed that several of the approximately 50-bp stretches within the enhancer contribute to its function in partially redundant fashion. Other stretches within the enhancer are inhibitory. Some of the stretches within the enhancer proved to be redundant with sequences within core ars3002. Consequently the collection of sequences important for core origin function was found to depend on whether the core origin is assayed in the presence or absence of the enhancer. Some of the important sequences in the core origin and enhancer co-localize with short runs of adenines or thymines, which may serve as binding sites for the fission yeast Origin Recognition Complex (ORC). Others co-localize with matches to consensus sequences commonly found in fission yeast replication origins. CONCLUSIONS: The enhancer within the ura4 origin cluster in fission yeast contains multiple sequence motifs. Many of these stimulate origin function in partially redundant fashion. Some of them resemble motifs also found in core origins. The next step is to identify the proteins that bind to these stimulatory sequences.

Journal Article↗

Quantitative determination of medroxyprogesterone acetate in plasma by liquid chromatography/electrospray ion trap mass spectrometry.

A sensitive and rapid liquid chromatography/electrospray ion trap mass spectrometry (LC/MS/MS) method has been developed for the quantitative determination of medroxyprogesterone acetate (MPA) in human plasma. Plasma samples (1.0 mL) were simply extracted with pentane and the extracts were analyzed by HPLC with the detection of the analyte in the selective reaction monitoring (SRM) mode. The determination of MPA was accurate and reproducible, with a limit of quantitation of 0.05 ng/mL in plasma. The standard calibration curve for MPA was linear (r = 0.998) over the concentration range 0.05-6.0 ng/mL in human plasma. Analysis precision over the concentration range of MPA was lower than 18.8% (relative standard deviation, RSD) and accuracy was between 96.2 and 108.7%.

Calibration↗

Cathepsin L: a predominant heat-activated proteinase in arrowtooth flounder muscle.

Characterization of the autolytic profile of arrowtooth flounder (ATF) muscle indicated the involvement of heat-activated proteinases active at both acidic and alkaline pH values. Further assay of fish extract exhibited the maximum activity at 60 degrees C against casein used as a substrate at both pH 5.5 and 8.0. The maximum activity shifted to lower temperatures by the addition of urea with two distinctive patterns: activity reduction at pH 5.5 and activity enhancement at pH 8.0. The highest inhibition by E-64 indicated the proteinase belongs to the cysteine proteinase class. At pH 5.5, the proteinase hydrolyzed Z-Phe-Arg-NMec and all types of protein substrates tested at higher rate than that at pH 8.0. Activity bands, observed on the activity-stained substrate gels, indicated similar proteinases are responsible for the proteolytic activity observed at both pH values. When proteins of fish extract were separated by HPLC-SEC, only one proteolytic peak was observed at the retention time of 26 min with an estimated molecular weight of 39800 Da. The results implied cathepsin L is a predominant proteinase responsible for autolysis of ATF muscle at elevated temperatures.

Animals↗

Livedoid vasculitis responding to PUVA therapy.

BACKGROUND: Livedoid vasculitis is a chronic disorder manifested as recurrent, painful, reticulated, and ulcerative lesions of the legs, which result in ivory atrophic scars with peripheral telangiectasia and hyperpigmentation. Its etiology remains obscure and therapy is difficult. In this study, we evaluated the clinical efficacy of psoralen plus UVA (PUVA) therapy and its side-effects in the treatment of livedoid vasculitis. METHODS: Eight South Korean patients with livedoid vasculitis were treated with UVA and 8-methoxypsoralen (8-MOP). Systemic PUVA was started with 4 J/cm2 of UVA two or three times a week, and then the dose was increased by 0.5 or 1 J/cm2 increments at each subsequent treatment as tolerated. The effects of treatment were evaluated using photographs of before, during, and after the study. RESULTS: All patients experienced rapid cessation of new lesion formation, significant symptom relief, and complete healing of primary lesions. The mean times for each of the above were 3.6, 5.9, and 10 weeks, and the mean cumulative doses of UVA for each of the above were 55.9, 96.8, and 197.9 J/cm2, respectively. The patients tolerated PUVA therapy well without unacceptable side-effects. CONCLUSIONS: We propose that systemic PUVA using 8-MOP should be investigated further as an alternative treatment for patients with livedoid vasculitis.

Adult↗

Focal pulmonary uptake during Tc-99m myocardial perfusion SPECT imaging.

PURPOSE: To evaluate the incidence and origin of abnormal focal pulmonary uptake during myocardial perfusion SPECT imaging (MSPECT). METHODS: For evaluation of chest pain, 790 men and 581 women (mean age, 56 +/- 13 years) underwent MSPECT. All of them received adenosine for pharmacologic stress and Tc-99m tetrofosmin (TF, n = 817) or Tc-99m sestamibi (MIBI, n = 554) for myocardial perfusion imaging. RESULTS: Review of chest radiography with or without computed tomography revealed 111 (8.1%) focal pulmonary diseases. Among them, 38 (34.2%) showed focal pulmonary uptake (TF, 22; MIBI, 16); 27 (30.7%) of 88 showed previous pulmonary tuberculosis; 2 of 10 (20%) benign pulmonary nodules; 4 of 5 (80%) metastatic lung cancers; 2 of 4 (50%) primary lung cancers; and 3 of 4 (75%) pneumonias. No difference in uptake was noted for the two imaging agents. Intensity of uptake did not vary with origin of the uptake. Focal abnormal pulmonary uptake was found in 2.8% of patients undergoing MSPECT and in 34.2% of patients in whom radiological examinations showed regional pulmonary disease. In patients with abnormal pulmonary uptake on MSPECT, 16% had a malignant lesion, whereas 75% of patients with a pulmonary nodule shown on radiography and focal pulmonary uptake on MSPECT had a malignant lesion. CONCLUSIONS: Although the incidence of abnormal pulmonary uptake during MSPECT was very low, the incidence of malignant lesions in the patients with nodular pulmonary uptake was relatively high.

Adenosine↗

Tuberculous versus pyogenic arthritis: MR imaging evaluation.

PURPOSE: To assess magnetic resonance (MR) imaging features in differentiating tuberculous arthritis from pyogenic arthritis. MATERIALS AND METHODS: Findings in 29 patients with tuberculous arthritis were compared with those of 13 patients with pyogenic arthritis. Bone erosion, marrow signal intensity, synovial lesion signal intensity, boundaries (smooth or irregular) for extraarticular extension of infection, and abscess rim enhancement (thin and smooth or thick and irregular) were analyzed. RESULTS: Bone erosion was more common in patients with tuberculous arthritis (24 [83%] of 29) than in those with pyogenic arthritis (six [46%] of 13) (P =.026), while subchondral marrow signal intensity abnormality was seen more frequently in patients with pyogenic arthritis (12 [92%] of 13) than in those with tuberculous arthritis (17 [59%] of 29) (P =.036). On T2-weighted images, there was no significant difference between the synovial lesion signal intensities of tuberculous arthritis and pyogenic arthritis. Lesions in 16 (70%) of 23 patients with tuberculous arthritis and two (17%) of 12 patients with pyogenic arthritis had smooth extraarticular boundaries, while those in seven (30%) of 23 patients with tuberculous arthritis and 10 (83%) of 12 patients with pyogenic arthritis had irregular boundaries (P =.005). Tuberculous abscesses (16 [100%] of 16) had thin and smooth rim enhancement, while most pyogenic abscesses (five [71%] of seven) had thick and irregular rims (P =.001). CONCLUSION: MR imaging of bone abnormalities, extraarticular lesions, and associated abscesses provides useful information in the differentiation of tuberculous arthritis and pyogenic arthritis.

Abscess↗

Inflammatory pseudotumour involving the skull base and cervical spine.

Inflammatory pseudotumour (IPT) is an idiopathic condition characterized by sclerosing inflammation, which mimics a neoplastic process. IPT involving the skull base and cervical spine is distinctly rare and usually indistinguishable from aggressive neoplasms or infection. We report a case of IPT involving the skull base and cervical spine. Initially the patient complained of headache and hearing loss without other neurological dysfunction. Two cycles of oral systemic steroid therapy resulted in only partial responses. Low dose radiotherapy was followed by quadriparesis as the lesion infiltrated into the cervical vertebral bodies. Subsequently a second course of radiation was administered to the whole cervical spine. Marked improvement was observed clinically and radiologically; however, the patient gradually deteriorated and died of sepsis. Given the aggressive nature of disease and the complications related to the long-term treatment, we suggest that a more aggressive therapeutic approach is suitable in extensive IPT of the skull base.

Cervical Vertebrae↗

Moyamoya disease initially presenting visual field defect.

Progressive narrowing of distal carotid arteries and the development of compensatory fine networks are the characteristic findings of moyamoya disease. Cerebral infarction in moyamoya disease is due to a decreased blood flow and shows an uneven distribution in the distal bed of the anterior and middle cerebral arteries. The progression of disease in the posterior circulation follows that in the anterior circulation. Posterior circulation symptoms due to cerebral infarction usually occur in the advanced stage of the disease and follow the anterior circulation symptoms. We encountered an unusual case of moyamoya disease which initially presented with a transient visual field defect. One month later our patient developed blindness and her cerebral angiography showed advanced moyamoya disease.

Adult↗

Effect of heavy metals (Cu, Pb, and Ni) on the compositions of EPS in biofilms.

A series of batch adsorption tests to estimate the biofilm capacity for removal of the heavy metals (Cu, Pb, and Ni) in wastewater were carried out. The metal sorption results were fitted to the Freundlich isotherm model to compare their sorption capacity. The change of the composition of EPSs (extracellular polymeric substances) was simultaneously represented by the ratio of carbohydrate to protein (C/P) when the biofilm was exposed to the heavy metals. EPS composed of slime loosely bound to the cell and capsular materials was extracted by the four general extraction methods including regular centrifugation, regular centrifugation with formaldehyde, EDTA extraction and steam extraction. Although the various extraction methods showed different results, C/P ratio of biofilm exposed to copper and lead metal ions was generally lower than that of control.

Adsorption↗

Bioflocculation production from lower-molecular fatty acids as a novel strategy for utilization of sludge digestion liquor.

We propose the bioproduction of a bioflocculant from lower-molecular fatty acids as an innovative strategy for utilizing waste sludge digestion liquor. Fundamental studies on the production, characterization and application of a novel bioflocculant were performed. Citrobactersp. TKF04 was screened out of 1,564 natural isolates as a bacterial strain capable of a bioflocculant from acetic and propionic acids. TKF04 produced the bioflocculant during the logarithmic growth in the batch cultivation, and it could be recovered from the culture supernatant by ethanol precipitation. The fed-batch cultivation with feeding of acetic acid: ammonium 10;1 (mole) to maintain pH 8.5 led to the hyper-production of the bioflocculant. The bioflocculant was found to be effective for flocculating a kaolin suspension, when added at a final concentration of 1-10 mg/l, over a wide range of pHs (2-8) and temperatures (3-95 degrees C), while the addition of cations was not required. It could flocculate a variety of inorganic and organic suspended particles including kaolin, diatomite, bentonite, activated carbon, soil and activated sludge. These indicated that the bioflocculant possesses flocculating activity comparable or superior to that of synthetic flocculants. The bioflocculation was identified as a chitosan-like biopolymer.

Bioreactors↗