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Lee HS, Oh JY, Lee JH, Yoo CG, Lee CT, Kim YW, Han SK, Shim YS, Yim JJ. Response of pulmonary tuberculomas to anti-tuberculous treatment. Eur Respir J 2004; 23:452-5. [PMID: 15065838 DOI: 10.1183/09031936.04.00087304] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Pulmonary tuberculomas are well-circumscribed masses caused by Mycobacterium tuberculosis. However, the response of tuberculomas to anti-tuberculous (TB) treatment has not been well defined as yet. The response of pulmonary tuberculomas to anti-TB treatment was retrospectively reviewed in 45 patients diagnosed between January 1997 and December 2001. The areas of pulmonary tuberculomas were estimated by calculating products of the longest and their perpendicular short diameters on chest radiographs. The response to anti-TB treatment was categorised as "decreased" (> 25% reduction in area versus its initial area), "increased" (> 251% increase) and "no change" (the remainder). The mean of treatment duration was 11.5 +/- 3.6 months. Three months after treatment, 18 patients (40.0%) were categorised as decreased, 25 (55.6%) as no change and two (4.4%) as increased. Twelve months after treatment, out of 42 patients available for chest radiographs, 32 patients (76.2%) were categorised as decreased, nine (21.4%) as no change and one patient (2.4%) as increased. At the last follow-up (mean follow-up 27.0 +/- 10.2 months), 37 patients (82.2%) were categorised as decreased. The majority of pulmonary tuberculomas were decreased by anti-tuberculosis treatment during and even after treatment, although a transient enlargement during the early period of treatment was observed infrequently.
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Lin CY, Lee SC, Lin CC, Chan SC, Lee CT. Isolated fatal renal mucormycosis in a patient with chronic obstructive pulmonary disease and tuberculosis. Int J Clin Pract 2003; 57:916-8. [PMID: 14712898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/05/2023] Open
Abstract
Renal mucormyosis is a rare entity and normally diagnosed at postmortem. Isolated cases diagnosed antemortem are even rarer and only a few cases have been reported. The disease is associated with a high mortality rate, especially in patients with underlying disease. Clinical presentation is non-specific and includes flank pain, fever and pyuria with or without haematuria. Identifying fungal hyphae microscopically is essential for diagnosis. We present a rare isolated fatal case of renal mucormycosis in a 77-year-old man with chronic obstructive pulmonary disease (COPD) and old tuberculosis (TB) who had been diagnosed after a right nephrectomy. We believe early diagnosis and appropriate treatment for fungal infection, together with the predisposing underlying disease, is crucial for survival.
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Abstract
AIMS To identify clinical features and treatment response of tuberculous peritonitis (TBP) in a uremic population, a retrospective case-control study was performed. MATERIALS AND METHODS Thirteen uremic patients with TBP (Group I: 62.7 +/- 6.8 years, male 54%) collected between January 1986 and January 2002 were compared with another two age- and sex-matched controls: 19 non-azotemic patients with TBP (Group II: 62.9 +/- 7.3 years, male 47%) and 30 uremic patients without TBP (Group III: 61.1 +/- 8.7 years, male 47%). Clinical information and data of ascites and blood examinations were evaluated. RESULTS Significant differences between Groups I and II were found in comorbidity, hypertension, anorexia, percentages of neutrophil and lymphocyte from blood and ascites, and serum calcium (sCa), phosphorus and albumin-adjusted calcium (sAACa). However, no significant differences in duration of symptoms, coexistent pulmonary tuberculosis (p = 0.061), duration or complications of therapy and mortality (p = 0.13) were detected. Significant differences between Groups I and III were found in peripheral white cell counts and percentages of neutrophil and lymphocyte as well as in serum creatinine (sCr), albumin, sCa, sAACa and intact parathyroid hormone (iPTH). CONCLUSIONS Non-specific symptoms make the diagnosis of TBP in a uremic population difficult. However, neutrophil predominance in blood and ascites, hypoalbuminemia, relatively lower sCr and hypercalcemia with suppressed serum iPTH were found to be characteristic. In TBP uremic patients, therapy complications were not common and there was a tendency for higher mortality, largely due to septic shock.
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Um SW, Yoo CG, Lee CT, Han SK, Shim YS, Kim YW. Apparent primary pleural melanoma: case report and literature review. Respir Med 2003; 97:586-7. [PMID: 12735679 DOI: 10.1053/rmed.2003.1482] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Tan LK, Tan HK, Lee CT, Tan ASA. Outcome of pregnancy in Asian women with systemic lupus erythematosus: experience of a single perinatal centre in Singapore. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2002; 31:290-5. [PMID: 12061288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
OBJECTIVE To study maternal and fetal outcomes in women with systemic lupus erythematosus (SLE). MATERIALS AND METHODS Retrospective study of 27 pregnancies in 18 women with SLE in a single centre. RESULTS The mean age was 30 years and most patients were nulliparous. Twenty-six of 27 pregnancies were in disease remission at the time of booking. Renal impairment was present in 7 pregnancies (6 women), of whom 2 were in end-stage renal disease on dialysis. Gestational diabetes developed in 4 pregnancies. There were 6 cases of pre-existing hypertension and 5 with superimposed pre-eclampsia. One woman developed intrapartum eclampsia. Two women had secondary antiphospholipid syndrome (APS) and suffered late fetal losses; in addition, they also developed SLE flares in the form of autoimmune haemolytic anaemia in the postpartum period. There was no maternal mortality. There was one termination of pregnancy for severe renal disease. The median gestational age at delivery was 38 weeks (range, 24 to 40 weeks) and the mean birth weight was 3047 g; the median Apgar scores were 8 and 9 at 1 and 5 minutes of life, respectively. There were 5 cases of intrauterine growth restriction (IUGR), 4 of which occurred in women with renal impairment. There were no cases of congenital heart block or neonatal lupus. There was a late fetal loss at 24 weeks in a woman with secondary APS. There were 2 preterm deliveries (7.4%) due to intervention for IUGR. CONCLUSION Good pregnancy outcomes can be expected in women with SLE in remission. Pre-pregnancy counselling is crucial to achieve this. All pregnancies should still be considered high risk and be managed jointly between the obstetricians, the perinatologists and the physicians. In particular, those with renal impairment are at increased risk of IUGR, superimposed pre-eclampsia and preterm births. Co-existing APS augurs a poorer prognosis for pregnancy outcome, and may present atypically as autoimmune haemolytic anaemia in the postpartum period.
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Abstract
The incidence and causes of perioperative ulnar neuropathy in a prospective series of 203 consecutive patients were examined. Three percent of patients had ulnar neuropathy develop in the entire prospective series. The incidence was 6% in patients having total hip arthroplasty. There was a highly significant association between a tilted body position on the operating table and development of ulnar neuropathy on the contralateral side. This position rotates the arm internally and places the ulnar nerve at risk for direct compression.
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Yoo JH, Lee CT, Shim YS, Chung JW, Ahn H, Kim KW. Aortobronchial fistula presenting as recurrent hemoptysis and successfully treated with an endovascular stent graft. Respiration 2002; 68:537-9. [PMID: 11694820 DOI: 10.1159/000050565] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Aortobronchial fistula (ABF) (aortopulmonary fistula) may cause a massive fatal hemoptysis. We have recently seen a patient with ABF presenting with recurrent, massive hemoptysis. She was successfully treated with an endovascular stent graft. The endovascular stent graft may provide an alternative treatment of in patients considered to be poor surgical candidates.
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Lee CT, Hung KH, Fang JS, Chen MC, Chen JB, Hsu KT. Implications of sonographic identification of duplex kidney in adults. CHANG GUNG MEDICAL JOURNAL 2001; 24:779-85. [PMID: 11858393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
BACKGROUND Duplication of the renal pelvis and ureter constitutes the most common anomalies of the upper urinary tract. Most patients are asymptomatic and don't need treatment. However, the associated anomaly and acquired renal disease may cause morbidity and mortality. The aim of this study was to investigate the prevalence of duplex kidney in sonographic examinations and the predictive capability of this method. An analysis of patients with urography-confirmed duplication anomaly was also performed. METHODS During a period of 9 year (from 1988 to 1996), sonographic examination records of 19,287 patients were reviewed. Patients with a diagnosis of duplex kidney were enrolled. Their clinical characteristics and radiological images were recorded and evaluated. RESULTS One hundred and sixty-three patients were found by sonography to have duplex kidney, for an prevalence of 0.85%. Urography studies were done on 64 (39.2%) patients, and 42 patients were proven to have duplex kidney. The positive predictive rate of sonography was 65.6%. Eighty percent of patients with duplex kidney had associated ureteral duplication. No associated anomalies were found. Four patients had urolithiasis, and 3 patients had recurrent urinary tract infection. One patient had coexisting uroepithelial malignancy, and 1 patient had refractory gross hematuria. CONCLUSIONS Duplex kidney is an uncommon finding during adult sonographic examinations. The sensitivity and specificity of sonography in identifying this anomaly are controversial. An experienced hand with good knowledge of the anomaly and its sonographic signs is helpful in more accurately diagnosing this anomaly.
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Yeung LK, Lee CT, Johnston KP, Crooks RM. Catalysis in supercritical CO2 using dendrimer-encapsulated palladium nanoparticles. Chem Commun (Camb) 2001:2290-1. [PMID: 12240155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
Dendrimer-encapsulated nanoparticles are shown to be versatile catalysts for both the hydrogenation of styrene and Heck heterocoupling of iodobenzene and methacrylate in supercritical CO2 (scCO2).
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Hung KH, Lee CT, Gau YL, Chen JB. Neglected bilateral femoral neck fractures in a patient with end-stage renal disease before chronic dialysis. Ren Fail 2001; 23:827-31. [PMID: 11777322 DOI: 10.1081/jdi-100108194] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Bilateral femoral neck fractures are rarely reported in patients with end-stage renal disease before chronic dialysis. We report on a 39-year-old woman with neglected bilateral femoral neck fractures, who presented with severe uremic complications prior to chronic dialysis. Three years before admission, she had injured herself in a trivial slip with subsequent bilateral hip pain. She had progressively waddled since then. Pelvic X-ray taken after admission revealed bilateral femoral neck fractures. Bilateral hip hemiarthroplasties were subsequently performed. Displaced femoral neck fractures were found intraoperatively. Pathologic findings and results of examinations supported the coexistence of osteoporosis and high turnover renal osteodystrophy, rendering this woman at high risk of bilateral femoral neck fractures. Therefore, preventing a simple fall or trivial accident and treating renal osteodystrophy and osteoporosis are paramount in patients with chronic renal failure even before the start of dialysis therapy. We also emphasize the need to seek any possible underlying metabolic bone disease once a patient presents with unusual fractures.
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Joh YH, Kim TY, Na II, Oh DY, Kim BS, Kim JH, Kim DY, Lee SH, Yoo CG, Lee CT, Kim YW, Heo DS, Bang YJ, Han SK, Shim YS, Kim NK. Phase II Trial of Vinorelbine and Cisplatin Chemotherapy in Advanced Non-Small Cell Lung Cancer. Cancer Res Treat 2001; 33:373-6. [PMID: 26680810 DOI: 10.4143/crt.2001.33.5.373] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
PURPOSE Platinum-based chemotherapy has conferred a modest but significant survival benefit and the introduction of newer drugs has led to achieve higher response rate in patients with advanced non-small cell lung cancer (NSCLC). We performed a phase II trial in order to evaluate the efficacy and toxicity of combination chemotherapy with vinorelbine (Navelbine) and cisplatin in advanced NSCLC. MATERIALS AND METHODS Patients with previously untreated, unresectable stage IIIB or IV NSCLC with measurable lesion (s) were eligible for entry into the study. NP chemotherapy consisted of intravenous vinorelbine 25 mg/m2, on day 1 and 8, and intravenous cisplatin 80 mg/m2 on day 1; this cycle was repeated every three weeks. RESULTS A total of 33 patients were enrolled in the study between July 1999 and Feb 2000. Of the 30 patients deemed eligible for analysis, thirteen patients achieved a partial response and thirteen showed a stable disease. The overall response rate was 43.3%. The median duration of response was 5.7 months (95% CI: 2.8~8.5 months). The median time to progression was 7.6 months (95% CI: 5.5~9.7 months) and the overall median survival time was 15.1 months (95% CI: 9.8~20.4 months) in the intent-to-treat analysis. Chemotherapy-related grade 3 or 4 toxicities were anemia in 1.5%, leukopenia in 4.5%, nausea/vomiting in 2.3%, alopecia in 13.3%, and neurotoxicity in 3.3%. CONCLUSION The combination of vinorelbine and cisplatin chemotherapy seems to be active and fairly tolerable in patients with advanced NSCLC.
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Chen PY, Lin CK, Lee CT, Jan H, Chan SI. Effects of turn residues in directing the formation of the beta-sheet and in the stability of the beta-sheet. Protein Sci 2001; 10:1794-800. [PMID: 11514670 PMCID: PMC2253197 DOI: 10.1110/ps.49001] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The designed peptide (denoted 20-mer, sequence VFITS(D)PGKTYTEV(D)PGOKILQ) has been shown to form a three-strand antiparallel beta-sheet. It is generally believed that the (D)Pro-Gly segment has the propensity to adopt a type II' beta-turn, thereby promoting the formation of this beta-sheet. Here, we replaced (D)Pro-Gly with Asp-Gly, which should favor a type I' turn, to examine the influence of different type of turns on the stability of the beta-sheet. Contrary to our expectation, the mutant peptide, denoted P6D, forms a five-residue type I turn plus a beta-bulge between the first two strands due to a one amino-acid frameshift in the hydrogen bonding network and side-chain inversion of the first beta-strand. In contrast, the same kind of substitution at (D)Pro-14 in the double mutant, denoted P6DP14D, does not yield the same effect. These observations suggest that the SDGK sequence disfavors the type I' conformation while the VDGO sequence favors a type I' turn, and that the frameshift in the first strand provides a way for the peptide to accommodate a disfavored turn sequence by protruding a bulge in the formation of the beta-hairpin. Thus, different types of turns can affect the stability of a beta-structure.
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Park KH, Seol JY, Kim TY, Yoo CG, Kim YW, Han SK, Shim YS, Lee CT. An adenovirus expressing mutant p27 showed more potent antitumor effects than adenovirus-p27 wild type. Cancer Res 2001; 61:6163-9. [PMID: 11507068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
The main inhibitory action of p27, a cyclin-dependent kinase inhibitor (CDKI), arises from its binding with the cyclin E/cyclin-dependent kinase 2 (Cdk2) complex that results in G(1)-S arrest. Degradation of p27 is mediated by phosphorylation of Thr-187 of p27, which follows ubiquitination. In this study, we generated two adenoviruses expressing wild-type p27 (ad-p27wt) and mutant p27 (ad-p27mt), with mutation of Thr-187/Pro-188 (ACGCCC) to Met-187/Ile-188 (ATGATC), which was produced with the belief that mutant p27 would bind cyclin E/CDK2 more stably and show more potent antitumor effects. Ad-p27wt and ad-p27mt expressed p27 proteins that were indistinguishable by anti-p27 antibody. A pulse chase experiment showed that p27mt was more resistant to degradation than p27wt. In human lung cancer cell lines, ad-p27mt showed stronger growth inhibition than ad-p27wt. Both types of ad-p27 induced G(1)-S arrest and apoptosis; however, ad-p27mt induced stronger G(1)-S arrest and apoptosis. Intratumoral injection of ad-p27mt induced partial regression of established tumors and inhibited the growth of human lung cancer xenografts more strongly than ad-p27wt. From these results, we conclude that ad-p27mt has the potential to become a novel and powerful gene therapy tool.
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Herr HW, Lee CT, Sharma S, Hilton S. Radiographic versus pathologic size of renal tumors: implications for partial nephrectomy. Urology 2001; 58:157-60. [PMID: 11489688 DOI: 10.1016/s0090-4295(01)01173-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVES To compare the radiographic size with the pathologic size of renal tumors to determine whether these two measurements vary significantly and to evaluate whether any differences in tumor size could have an impact on the decisions regarding partial nephrectomy. METHODS In 87 renal tumors excised by partial nephrectomy, the maximum transaxial tumor size on computed tomography (CT) was compared with its corresponding pathologic transverse size. Tumors were locally excised after vascular occlusion and hypothermia. The average size of the tumors selected for partial nephrectomy by preoperative CT scan was 3.4 cm (range 1.9 to 9.3). The difference between the CT size and pathologic size was correlated with the histologic type of the renal tumors. RESULTS Of the 87 tumors, 52 (60%) were classified as clear cell carcinoma and 35 (40%) as other histologic types (papillary, chromophobe, oncocytoma, and angiomyolipoma). Clear cell carcinomas decreased an average of 0.97 cm versus 0.39 cm for the other tumor types. Of 62 tumors greater than 3 cm on CT, 43 averaged 0.87 cm smaller at pathologic evaluation (36 clear cell and 7 other types) and 19 showed no significant (less than 0.5 cm) decrease in size (2 clear cell and 17 other histologic types). Of 30 tumors greater than 4 cm on CT, 22 clear cell carcinomas shrank more than 1 cm and 8 tumors displaying other histologic features showed no decrease in size. CONCLUSIONS For renal tumors measuring greater than 4 cm, a decrease in tumor size may help facilitate partial nephrectomy, especially for clear cell carcinomas that do not extensively involve major vascular structures or the collecting system.
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Weiner AJ, Paliard X, Selby MJ, Medina-Selby A, Coit D, Nguyen S, Kansopon J, Arian CL, Ng P, Tucker J, Lee CT, Polakos NK, Han J, Wong S, Lu HH, Rosenberg S, Brasky KM, Chien D, Kuo G, Houghton M. Intrahepatic genetic inoculation of hepatitis C virus RNA confers cross-protective immunity. J Virol 2001; 75:7142-8. [PMID: 11435595 PMCID: PMC114443 DOI: 10.1128/jvi.75.15.7142-7148.2001] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Naturally occurring hepatitis C virus (HCV) infection has long been thought to induce a weak immunity which is insufficient to protect an individual from subsequent infections and has cast doubt on the ability to develop effective vaccines. A series of intrahepatic genetic inoculations (IHGI) with type 1a HCV RNA were performed in a chimpanzee to determine whether a form of genetic immunization might stimulate protective immunity. We demonstrate that the chimpanzee not only developed protective immunity to the homologous type 1a RNA after rechallenge by IHGI but was also protected from chronic HCV infection after sequential rechallenge with 100 50% chimpanzee infectious doses of a heterologous type 1a (H77) and 1b (HC-J4) whole-virus inoculum. These results offer encouragement to pursue the development of HCV vaccines.
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Abstract
Orphan nuclear receptors are members of the nuclear receptor superfamily of ligand-activated transcription factors for which ligands and functions have not been identified. Since the cloning of the original orphans, ligands have been identified for several orphan receptors that heterodimerize with the retinoid X receptor and are no longer classified as orphan receptors. Considering the central role that nuclear receptors play in differentiation, development, metabolic regulation, homeostasis and disease, it is crucial that we understand the roles of the remaining orphans. However, the identification of ligands for those orphans that form homodimers has proven more difficult. Thus, to gain greater insight into the functions of orphan receptors, gene targeting has been used to knock out these factors and study mouse development in their absence. Here we will review the progress made in understanding the roles of the orphans GCNF and the COUP-TFs with the use of gene knockouts.
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Kim DJ, Lee HP, Kim MS, Park YJ, Go HJ, Kim KS, Lee SP, Chae JH, Lee CT. The effect of total sleep deprivation on cognitive functions in normal adult male subjects. Int J Neurosci 2001; 109:127-37. [PMID: 11699337 DOI: 10.3109/00207450108986529] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
This study was conducted to evaluate the effect of acute sleep deprivation on cognitive functions. A total of 18 healthy right handed males were deprived of sleep for 24 hours. Luria-Nebraska Neuropsychological Battery and calculation & digit-span subtest of K-WAIS were administered before and after sleep deprivation in order to examine the changes of cognitive functions. There were no differences in freedom from distractibility, tacile function, visual function, reading, writing, arithmetic and intellectual process function. However, the cognitive functions such as motor, rhythm, receptive & expressive speech, memory and complex verbal arithmetic function were decreased after sleep deprivation. All of these functions are known to be related to the right anterior hemisphere. For localization scales, the scores of right frontal and right temporal dysfunction scale were increased after sleep deprivation. These results indicate that sleep deprivation has a negative effect on cognitive functions, especially those associated with right anterior hemisphere or subcortical areas.
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Lo YK, Wu SN, Lee CT, Li HF, Chiang HT. Characterization of action potential waveform-evoked L-type calcium currents in pituitary GH3 cells. Pflugers Arch 2001; 442:547-57. [PMID: 11510888 DOI: 10.1007/s004240100576] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The response of the L-type Ca2+ current (ICa,L) in pituitary GH3 cells to variations in the action potential (AP) waveform was examined using the whole-cell configuration of the patch-clamp technique. ICa,L evoked during an AP waveform exhibited an early and a late component. The early component occurred on the rising phase of the AP; the late component coincided with the falling phase. Prolonging the falling phase of the AP increased the Ca2+ charge carried by ICa,L, although the amplitude of the late ICa,L was reduced. Prolonging the peak voltage of the AP waveform, however, increased the amplitude of the late component. ICa,L inactivated during a train of AP waveforms. When Ba2+ was used as the charge carrier, current inactivation during a train of APs decreased. Likewise, ICa,L evoked by the AP templates with irregular bursting pattern was inactivated. When the repetitive firing of APs with depolarizing potentials was replayed to cells, Ca2+ entry was not only spread over the entire AP, but also occurred during the interspike voltage trajectory. After application of thyrotropin releasing hormone (TRH; 10 microM), ICa,L in response to rectangular pulses was increased and the current/voltage relation shifted slightly to more negative values. TRH (10 microM), thapsigargin (10 microM) or cyclopiazonic acid (30 microM) enhanced the late component of the AP-evoked ICa,L. TRH also attenuated the inactivation of ICa,L during a train of APs. These results indicate that in pituitary GH3 cells, the time course and kinetics of ICa,L during the AP waveforms is distinct from that evoked by rectangular voltage clamp. Changes in the shape and firing pattern of APs in GH3 cells can modulate Ca2+ influx through L-type Ca2+ channels. Ca2+ release from internal stores may affect the magnitude of AP-evoked ICa,L in these cells.
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Lee CT, Ng SH, Ko SF, Wan YL, Liu JW, Chen JB. Culture-negative tuberculous enterovesical fistula mimicking late urological complications after radiotherapy. Int J Tuberc Lung Dis 2001; 5:687. [PMID: 11467376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
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Lee CT, Yin Q, Rudnick RL, Jacobsen SB. Preservation of ancient and fertile lithospheric mantle beneath the southwestern United States. Nature 2001; 411:69-73. [PMID: 11333978 DOI: 10.1038/35075048] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Stable continental regions, free from tectonic activity, are generally found only within ancient cratons-the centres of continents which formed in the Archaean era, 4.0-2.5 Gyr ago. But in the Cordilleran mountain belt of western North America some younger (middle Proterozoic) regions have remained stable, whereas some older (late Archaean) regions have been tectonically disturbed, suggesting that age alone does not determine lithospheric strength and crustal stability. Here we report rhenium-osmium isotope and mineral compositions of peridotite xenoliths from two regions of the Cordilleran mountain belt. We found that the younger, undeformed Colorado plateau is underlain by lithospheric mantle that is 'depleted' (deficient in minerals extracted by partial melting of the rock), whereas the older (Archaean), yet deformed, southern Basin and Range province is underlain by 'fertile' lithospheric mantle (not depleted by melt extraction). We suggest that the apparent relationship between composition and lithospheric strength, inferred from different degrees of crustal deformation, occurs because depleted mantle is intrinsically less dense than fertile mantle (due to iron having been lost when melt was extracted from the rock). This allows the depleted mantle to form a thicker thermal boundary layer between the deep convecting mantle and the crust, thus reducing tectonic activity at the surface. The inference that not all Archaean crust developed a strong and thick thermal boundary layer leads to the possibility that such ancient crust may have been overlooked because of its intensive reworking or lost from the geological record owing to preferential recycling.
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Lee CT, Hoopes MF, Diehl J, Gilliland W, Huxel G, Leaver EV, McCann K, Umbanhowar J, Mogilner A. Non-local Concepts and Models in Biology. J Theor Biol 2001; 210:201-19. [PMID: 11371175 DOI: 10.1006/jtbi.2000.2287] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In this paper, we consider local and non-local spatially explicit mathematical models for biological phenomena. We show that, when rate differences between fast and slow local dynamics are great enough, non-local models are adequate simplifications of local models. Non-local models thus avoid describing fast processes in mechanistic detail, instead describing the effects of fast processes on slower ones. As a consequence, non-local models are helpful to biologists because they describe biological systems on scales that are convenient to observation, data collection, and insight. We illustrate these arguments by comparing local and non-local models for the aggregation of hypothetical organisms, and we support theoretical ideas with concrete examples from cell biology and animal behavior.
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Ko WC, Lee HC, Wang LR, Lee CT, Liu AJ, Wu JJ. Serotyping and antimicrobial susceptibility of group B Streptococcus over an eight-year period in southern Taiwan. Eur J Clin Microbiol Infect Dis 2001; 20:334-9. [PMID: 11453594 DOI: 10.1007/s100960100505] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The increase in penicillin resistance among pneumococci and viridans streptococci and the development of serotype-specific conjugate vaccine have increased the need for knowledge of the antimicrobial susceptibility and the capsular serotypes of group B streptococci. Over an 8-year period, 351 group B streptococcal isolates from southern Taiwan were tested for antimicrobial susceptibility and serotype determination. Eighty-seven percent of the isolates were typeable. Types III (28.5%) and V (27.1%) were the most common serotypes. The occurrence of type V isolates increased with age, while that of type III isolates decreased with age, showing a predominance in children less than 1 year of age. Of 118 isolates from cases of invasive infection, types Ia, Ib, II, III, IV, and V accounted for 12.7, 11.9, 0.8, 33, 1.7, and 26.3%, respectively. Using the agar dilution method, all isolates were found to be susceptible to penicillin, cefotaxime, and vancomycin, 99.4% to ofloxacin, 78.1% to chloramphenicol, 63.2% to azithromycin, 62.6% to erythromycin, 57.3% to clindamycin, and 2.8% to tetracycline. Chloramphenicol resistance was associated with type III isolates (59 of 100, 59%) and erythromycin and azithromycin resistance with type Ib isolates (25 of 33 176%], and 21 of 33 [64%], respectively). Thus, 72% of the isolates from invasive infections were serotype III, V, or Ia, and penicillin remains the drug of choice for treatment or prophylaxis of group B streptococcal infections in southern Taiwan, despite the high prevalence of penicillin resistance among Streptococcus pneumoniae and viridans streptococci.
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Kwon HC, Kim JH, Kim KC, Lee KH, Lee JH, Lee BH, Lee KH, Jang JJ, Lee CT, Lee H, Kim CM. In vivo antitumor effect of herpes simplex virus thymidine kinase gene therapy in rat hepatocellular carcinoma: feasibility of adenovirus-mediated intra-arterial gene delivery. Mol Cells 2001; 11:170-8. [PMID: 11355697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023] Open
Abstract
Transfer of the herpes simplex virus-thymidine kinase gene, followed by the administration of ganciclovir (HSV-tk/GCV), has been a major approach for cancer gene therapy. We investigated the antitumor effect of the HSV-tk/GCV strategy with the rat orthotopic hepatocellular carcinoma (HCC) model and the tumor-selective gene delivery by an adenovirus-mediated gene transfer through the hepatic artery. The complete antitumor effect was demonstrated, after the treatment with GCV in rat HCC established by the implantation of HSV-tk transferred rat HCC cells. The in vivo bystander effect was also observed. The marked infiltration of CD4+ and CD8+ T lymphocytes, macrophages and NK cells were found in the tumor area. After the injection of adenovirus carrying the LacZ gene into the hepatic artery, the selective expression of transgene in the tumor cell was achieved. These findings indicate that the HSV-tk/GCV strategy, using an adenoviral vector, could be a promising avenue for the treatment of hepatocellular carcinoma.
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Kim TK, Mo EK, Yoo CG, Lee CT, Han SK, Shim YS, Kim YW. Alteration of cell growth and morphology by overexpression of transforming growth factor beta type II receptor in human lung adenocarcinoma cells. Lung Cancer 2001; 31:181-91. [PMID: 11165397 DOI: 10.1016/s0169-5002(00)00169-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
TGF-beta is a potent inhibitory regulator of cell growth, which is transduced through interaction between type I (RI) and type II (RII) receptors that form heteromeric kinase complexes. Abnormal expression of these receptors has been identified in several human epithelial cancers and has been shown to be highly associated with resistance to TGF-beta. In this study, we investigated the expression of RI and RII in 13 human non-small cell lung cancer cell lines (NSCLCs) and demonstrated decreased or loss of RII expression in five lung cancer cell lines, but not of RI. Of these cell lines, the role of RII in NCI-H358 adenocarcinoma, which lacks RII and is insensitive to TGF-beta, was investigated by transducing this cell line with a recombinant retrovirus expressing full-length TGF-beta RII. Stably transfected cells showed significant increase in RII mRNA and protein expression. These cells responded to exogenous TGF-beta1 with suppressed proliferation in a dose-dependent manner and G1 arrest accompanied by morphological change distinct from control cells. We also investigated whether overexpression of dominant-negative RII (dnRII) in NCI-H441 adenocarcinoma, which is sensitive but expresses low levels of RII, could block signaling through the receptor complex. The overexpression of this kinase-domain-truncated RII by expressing the retroviral dnRII construct led to loss of the ability to respond to TGF-beta1 and an exhibition of uncontrolled growth. These results suggest a close association between the loss of the expression of wild-type TGF-beta RII and carcinogenesis in human lung cancer cells.
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