Biomedical subjects
Publications and source records attributed to S W Han.
We report values of R = sigma(e(+)e(-)-->hadrons)/sigma(e(+)e(-)-->mu(+)mu(-)) for 85 center-of-mass energies between 2 and 5 GeV measured with the upgraded Beijing Spectrometer at the Beijing Electron-Positron Collider.
OBJECTIVE: To evaluate knowledge about the foreskin and circumcision, and to understand the attitudes of parents to circumcision in Korea, where circumcision in childhood is widely practised with no particular religious or medical background. SUBJECTS AND METHODS: A nationwide study involving questionnaires was conducted on 5500 parents with at least one son attending elementary school. Responses were obtained from one of the parents. RESULTS: The response rate was 76.1% (4183); circumcision was most common in boys when aged 11 years, followed by neonatal circumcision. Of the parents, 91.3% believed that circumcision is necessary, while 2.1% believed it to be unnecessary. The principal reasons given for circumcision were 'to improve penile hygiene' (82.4%), followed by 'to improve future sexual potency' (7.5%). Among those who did not believe circumcision to be necessary, the most common reason was the expectation of spontaneous retraction of the prepuce with age (55.1%). Most (88.4%) of the parents believed that smegma is not a clean material, and is infected by microorganisms. Most parents (80.6%) thought that circumcision would prevent genital tract infection of the future spouse. Peer pressure was one of the most influential factors in deciding upon circumcision; 41.9% of the parents were anxious that their child might be ridiculed by his peer group unless he was circumcised, while 27.4% of the parents believed that their child might be ridiculed if he was circumcised. Mothers were more positive about circumcision than fathers (P < 0.05). Parents with a higher education and higher socio-economic status were also more positive about circumcision (P < 0.05). Mothers were prone to emphasize improved sexual potency (P < 0.05). There was no significant difference in response between urban and rural areas. CONCLUSION: This study indicates that common beliefs held by parents about the prepuce or circumcision differ significantly from current medical knowledge, and these beliefs have a major influence on the practice of circumcision in Korea. More clinical research on the natural history of the foreskin is needed, and it is critical that both children and parents are informed about the potential benefits and disadvantages of circumcision.
The binding mode of porphyrins, namely meso-tetrakis(N-methyl pyridinium-4-yl)porphyrin (H(2)TMPyP), was classified in this work by absorption and circular dichroism(CD) spectroscopy. The three binding modes of intercalation, minor groove binding and external stacking exhibit their own characteristic absorption and CD spectra. Intercalation occurs for this porphyrin when bound to GC-rich polynucleotides at a low mixing ratio, as expected. This binding mode produces hypochromism and a red shift in the absorption band and a negative CD band in the Soret absorption region. When it is complexed with AT-rich polynucleotides at a low mixing ratio, hypochromism and a red shift in the absorption band and a positive CD peak is apparent, and this species can easily be assigned to the minor groove-binding mode. For both AT- and GC-rich polynucleotides at a high binding ratio, an excitonic CD was apparent. The sign of excitonic CD depends on the order of the DNA bases; the CD spectra of H(2)TMPyP complexed with non-alternating homopolymer (disregarding the nature of base pairs, i.e. AT or GC) are characterized by a positive band at short wavelengths followed by a negative band at long wavelengths. In contrast, those complexed with alternating polynucleotide were opposite to those of non-alternating homopolymers.
Dengue virus (DV) infection is a major problem in public health. It can cause fatal diseases such as Dengue hemorrhagic fever and Dengue shock syndrome. Dendritic cells (DC) are professional APCs required for establishing a primary immune response. Here, we investigated the role of human PBMC-derived DC in DV infection. Using different techniques, including plaque assay, flow cytometry analysis, nested RT-PCR, and confocal microscope and electron microscope examinations, we show that DV can enter cultured human DC and produce virus particles. After entrance, DV could be visualized in cystic vesicles, vacuoles, and the endoplasmic reticulum. The DV-infected DC also showed proliferation and hypertrophy of the endoplasmic reticulum as well as the swollen mitochondria. In addition, the DV-stimulated DC could express maturation markers such as B7-1, B7-2, HLA-DR, CD11b, and CD83. Furthermore, the infection of DC by DV induced production of TNF-alpha and IFN-alpha, but not IL-6 and IL-12. Although DC underwent spontaneous apoptosis in the absence of feeding cytokines, this process appeared to be delayed after DV infection. Our observations provide important information in understanding the pathogenesis of DV infection.
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PURPOSE: Voiding cystourethrography is routinely recommended to detect vesicoureteral reflux in children with ureteropelvic junction obstruction. Vesicouretral reflux coexisting with primary ureteropelvic junction obstruction is usually of low grade and resolves spontaneously after pyeloplasty, whereas pseudo ureteropelvic junction obstruction and obstruction secondary to high grade reflux usually present with a dilated ureter that is easily detected on real-time ultrasonography. We assessed the role of voiding cystourethrography in children with ureteropelvic junction obstruction by retrospectively evaluating the incidence and natural history of coexisting vesicourethral reflux. MATERIALS AND METHODS: We reviewed the records of 106 children younger than 15 years who underwent pyeloplasty for ureteropelvic junction obstruction at our hospital between January 1990 and December 1998. A patient who had initially undergone antireflux surgery later underwent pyeloplasty for newly developed secondary obstruction was not included in the analysis. The diagnosis of ureteropelvic junction obstruction was based on ultrasonography and diuretic renography. Preoperative voiding cystourethrography was performed in all patients to detect vesicourethral reflux. We categorized reflux as low grade if the ureters were not dilated and as high grade if the ureters were dilated and tortuous. RESULTS: There were 89 boys and 17 girls who underwent 115 pyeloplasties, including 9 who underwent bilateral pyeloplasty. Mean patient age at surgery was 27.4 months (63 infants, 6 between 1 and 2 years old, and 37 older than 2 years). Of these 106 patients 85 had unilateral (left side 64, right side 21) and 21 had bilateral ureteropelvic junction obstruction. Vesicourethral reflux was documented in 19 ureters of 12 children. Of the 85 cases of unilateral ureteropelvic junction obstructions 10 had vesicourethral reflux, which was bilateral 6, ipsilateral in 2 and contralateral in 2. Of the 21 cases of bilateral obstructions 2 had reflux, which was bilateral in 1 and was unilateral in 1. Reflux was low grade reflux in 6 and high grade in 6 cases. All low grade reflux disappeared spontaneously at an average period of 4.2 months (range 2 to 10) after pyeloplasty. All 6 patients with high grade reflux subsequently underwent antireflux surgery because of breakthrough urinary tract infection in 2 and persistent in 4 at an average of 36 months (range 3 to 112) after pyeloplasty. All high grade reflux coexisting with ureteropelvic junction obstruction was easily detected on real-time ultrasonography. CONCLUSIONS: Low grade reflux coexisting with ureteropelvic junction obstruction spontaneously disappeared after pyeloplasty, and all high grade reflux coexisting with obstruction was easily detected on ultrasonography using real-time mode. Therefore, we believe that indication for voiding cystourethrography in children with ureteropelvic junction obstruction should be limited to those with dilated ureters on ultrasonography.
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Elevated levels of immunoglobulin (Ig) E are associated with immediate-type allergic reactions. Jin-deuk-chal is the whole plant of Siegesbeckia orientalis (SO) sL Immunization of mice with small amounts of protein antigens on alum results in several fold increases in total plasma IgE, much of it specific for the immunizing antigen. In the present study, we investigated the effect of Siegesbeckia orientalis (SO) on IgE production. SO inhibited the plasma levels of IgE induced by antigens. The effects of SO on the interleukin (IL)-4-dependent IgE response by mouse whole spleen cells were studied. IL-4 dependent IgE production of lipopolysaccharide (LPS)-stimulated whole spleen cells was inhibited by SO. In addition, using U266B I human IgE-bearing B cells, we found that SO inhibited the production of IgE activated by LPS plus IL-4. These results suggest that SO have antiallergic activity by inhibition of IgE production from B cells.
A construct (AT1R-NF) containing a "Flag" sequence added to the N-terminus of the rat AT1 receptor was stably expressed in Chinese hamster ovary cells and quantified in the cell membrane by confocal microscopy after reaction with a fluorescein-labeled anti-Flag monoclonal antibody. Angiotensin II bound to AT1R-NF and induced endocytosis with a half-time of 2 min. After 60-90 min, fluorescence accumulated around the cell nucleus, suggesting migration of the ligand-receptor complex to the nuclear membrane. Angiotensin antagonists also induced endocytosis, suggesting that a common step in the transduction signal mechanism occurring after ligand binding may be responsible for the ligand-receptor complex internalization.
Two examples of the rare case of complete duplicated collecting system with lower pole ureteropelvic junction obstruction are described. Ureteropelvic junction obstruction (UPJO) and duplicated collecting systems seldom occur in combination. Complete duplication of the ureter may be asymptomatic or recognized when complications develop as a result of reflux into the lower pole ureter or obstruction of the upper pole with an ectopic ureterocele. It is difficult to choose an optimal therapy due to the high variability in function, degree of obstruction, damage and potential for regeneration in growing kidneys. The diagnosis and management of UPJO of the lower pole in complete duplicated collecting systems are discussed.
Peroxisome proliferator-activated receptor gamma (PPAR-gamma) is a member of the nuclear receptor superfamily of ligand-dependent transcription factors that has been shown to play a major role in adipocyte and monocyte/macrophage differentiation. Recent work has also suggested a role for PPARgamma in cell cycle control and/or differentiation of other cell types including breast and lung cancer cells. Using reverse transcription-PCR, we now show for the first time that human neuroblastoma (nb) cells express PPARbeta and -gamma, but not -alpha. Using the LA-N-5 nb cell line, we have determined that the natural PPARgamma ligand 15-deoxy-delta prostaglandin J2, as well as the synthetic PPARgamma agonist GW1929, can stimulate the differentiation of nb cells, as evidenced by the inhibition of cell proliferation, neurite outgrowth, increased acetylcholinesterase activity, and the reduction of N-myc expression. We have also demonstrated that PPARgamma is expressed in primary nb and, furthermore, that the expression of this receptor correlates with the maturational stage of the nb cells. Taken together, these studies have implicated a role for PPARgamma in peripheral nerve cell biology and suggest that the PPARgamma signaling pathway is involved in the regulation of nb cell growth and differentiation.
PURPOSE: We examine if there is a relationship between the histopathology of the renal pelvis and postoperative radiological findings in children with ureteropelvic junction obstruction. MATERIALS AND METHODS: The records of 220 patients who underwent pyeloplasty for isolated ureteropelvic junction obstruction between 1988 and 1996 were retrospectively reviewed, and 41 (42 kidneys) were identified who had adequate histological specimens and postoperative radiographic studies (ultrasonography and/or well tempered renogram) for examination. Histological features of the lamina muscularis propria from the renal pelvis were correlated with the radiographic outcome after pyeloplasty. RESULTS: Lamina muscularis propria thickness of the renal pelvis correlated significantly with radiological improvement. All kidneys with renal pelvic lamina muscularis propria thickness less than 250 microm. showed radiological improvement at 3 to 6 months postoperatively, those with thickness between 250 and 350 microm. had improvement at 9 months and those with lamina thickness greater than 350 microm. had a significantly worse outcome at all observation points. At 3 and 6 months postoperatively 16 of 30 (53%) and 23 of 34 (68%) children with radiological improvement had a mean lamina muscularis propria thickness of 252 +/- 131.5 microm. and 263 +/- 122.8 microm., respectively, while the remaining unimproved 14 and 12 patients had a mean thickness of 374 +/- 64.3 microm. (p <0.01) 372 +/- 66.1 microm. (p <0.05), respectively. CONCLUSIONS: The lamina muscularis propria thickness of the renal pelvic wall can provide insight to the expected time of postoperative improvement on radiological studies in children with ureteropelvic junction obstruction.
Mutations in two genes, presenilin 1 (PS1) and presenilin 2, are linked to early onset cases of familial Alzheimer's disease. The presenilins are thought to contribute to the pathogenesis of Alzheimer's disease by directly or indirectly affecting the proteolytic processing of the amyloid precursor protein. They have also been implicated in the proteolytic processing of Notch. In PS1-deficient mammalian cells, the proteolytic release of the Notch intracellular domain is reduced. Likewise, loss-of-function mutations in Drosophila presenilin (Psn) prevent the production of the intracellular Notch signaling fragment and lead to phenotypes resembling Notch mutants. Here we characterize the Drosophila Psn protein and demonstrate that it undergoes a proteolytic cleavage. We describe Psn expression at different developmental stages of the fly and show Psn localization near both apical and basal plasma membranes. Furthermore, we demonstrate that portions of the Psn protein span the plasma membrane in S2 cells.
The binding mode of norfloxacin, a quinolone antibacterial agent, in the synthetic polynucleotides poly[d(G-C)2], poly[d(I-C)2] and poly[d(A-T)2] was studied using polarized light spectroscopy, fluorescence spectroscopy and melting profiles. The absorption, circular and linear dichroism properties of norfloxacin are essentially the same for all the complexes, and the angle of electric transition dipole moment I and II of norfloxacin relative to the DNA helix axis is measured as 68-75 degrees for all complexes. These similarities indicate that the binding mode of norfloxacin is similar for all the polynucleotides. The decrease in the linear dichroism (LD) magnitude at 260 nm upon binding norfloxacin, which is strongest for the norfloxacin-poly[d(G-C)2] complex, and the identical melting temperature of poly[d(A-T)2] and poly[d(I-C)2] in the presence and absence of norfloxacin rule out the possibility of classic intercalation and minor groove binding. However, the characteristics of the fluorescence emission spectra of norfloxacin bound to poly[d(A-T)2] and to poly[d(I-C)2] are similar but are different to that of norfloxacin bound to poly[d(G-C)2]. As the amine group of the guanine base protrudes to the minor groove, this result strongly suggests that norfloxacin binds in the minor groove of B-form DNA in a nonclassic manner.
OBJECTIVE: The Inflammatory Bowel Disease Questionnaire (IBDQ) is an instrument that assesses quality of life in patients with inflammatory bowel disease. It has 32 items in four domains. The short form of the IBDQ (SIBDQ) was developed in Canadian Crohn's disease patients for use in clinical practice. Patients with ulcerative colitis might require a different form of the SIBDQ. Our aim was to design and validate a SIBDQ for patients with ulcerative colitis and to compare this to the Crohn's SIBDQ. METHODS: We recruited 122 patients with colitis as an initial sample. Using linear regression modeling, the 10 items that best predicted the total IBDQ score were identified. The colitis and Crohn's versions of the SIBDQ were compared by univariate linear regression with the total IBDQ score in two other cohorts of colitis patients. RESULTS: Ten items explained 97% of the variance of the total IBDQ score in our first cohort. These were items 1 and 9 (bowel); 7, 11, 21, 30 (emotional); 2 and 10 (systemic); and 12 and 28 (social). Only three items were shared with the Crohn's SIBDQ. The R2 for both SIBDQs with the total IBDQ score in the other cohorts were very high (> or =0.95), although the Colitis SIBDQ showed better internal consistency. CONCLUSIONS: The development of a SIBDQ for patients with ulcerative colitis did not reveal any clear advantage over the original version of the SIBDQ. Further studies are required to determine the role of the SIBDQ in routine clinical practice.
The most consistently observed neurological deficits in the anterior choroidal artery (AChA) territory infarction are pure motor or sensorimotor syndromes. Visual field defects and higher cortical dysfunction are occasionally accompanied, but pure homonymous hemianopia without motor and sensory symptom has never been reported yet. We present 2 patients with pure homonymous hemianopia, whose MRI disclosed cerebral infarction in the well-known territory of the AChA. In most patients with ischemic stroke, pure homonymous hemianopia indicates infarction in the posterior circulation, particularly in the posterior cerebral artery territory. However, the present cases provide evidence that it can also be caused by infarction in the anterior circulation, i.e. the AChA.
Hypernatremia developing in nonhospitalized adults is predominantly a disease of the elderly and mentally handicapped patients, possibly revealing inadequate nursing care of these patients. It has long been claimed that the duration of hypernatremia and its rate of correction are correlated with improvement in patients' neurologic status. Since there are only a handful of cases with serum sodium levels greater than 200 mEq/L until recently, it is not clear at what rate plasma sodium concentration can be safely normalized in severe hypernatremic patients. We report a case of severe hypernatremia with survival. This patient underwent rapid correction of serum sodium concentration during the management of this metabolic derangement using isotonic solution.
BACKGROUND: Transjugular intrahepatic portosystemic shunt (TIPS) has been popularized for the treatment of refractory variceal bleeding. The aim of this study was to assess the safety and long-term effect of TIPS in the treatment of variceal bleeding that is not controlled with pharmacological and endoscopic treatment. METHODS: Thirty-six patients who underwent transjugular intrahepatic portosystemic shunt (TIPS) due to refractory variceal bleeding were included in the study. The effectiveness of portal decompression and bleeding control was evaluated. Upper gastrointestinal endoscopy was performed to analyse the degree of varices and portal hypertensive gastropathy (PHG) before TIPS procedure and one to three weeks after TIPS. Angiography was performed in surviving patients, if bleeding recurred, or if ultrasonography or endoscopy suggested stent dysfunction. RESULTS: TIPS were successfully placed in 36 of 38 patients (94.6%). TIPS achieved hemostasis of variceal bleeding in 34 patients (94.4%). Portal venous pressure decreased from an initial average of 28.7 +/- 7.9 to 23.2 +/- 9.4 mmHg after TIPS (p < 0.05). The portosystemic pressure gradient was significantly decreased from 15.5 +/- 6.3 to 7.8 +/- 4.1 mmHg (p < 0.01). The degree of esophagogastric varices and PHG was significantly improved after TIPS. The total length of follow-up was from one day to 54 months (mean: 355 days). The actuarial probability of survival was 83% at one year and 74% at two years. Overall, 16 episodes of stent dysfunction were diagnosed during follow-up. Stent revision by means of angioplasty was successfully performed in 14 of these episodes. CONCLUSION: TIPS is an effective and reliable nonoperative means of lowering portal pressure. This procedure has proved useful in the management of acute variceal bleeding refractory to endoscopic treatment. Surveillance by ultrasonography, endoscopy, and angiographic intervention is useful for the maintenance of shunt patency.