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Biomedical subjects

J Lee

Publications and source records attributed to J Lee.

At least 73 records · Page 4Linked to original sources

Two missense mutations of EGR2 R359W and GJB1 V136A in a Charcot-Marie-Tooth disease family.

During mutational analysis of Charcot-Marie-Tooth (CMT) causative genes, we identified a CMT family with two missense mutations in different genes. A R359W mutation in EGR2 was shared by the affected daughter (proband) and her father. In addition, she had a V136A mutation in GJB1, which was determined to be a de novo mutation. The daughter with two different gene mutations showed more severe clinical, electrophysiological and histopathological phenotypes than her father who had only the EGR2 mutation. We suggest that these phenotypic differences between the proband and her father may have been caused by an altered effect of the genetic modifier in EGR2, or by the additive effect of the EGR2 and GJB1 mutations.

Age of Onset↗

Effects of green tea consumption on inflammation, insulin resistance and pulse wave velocity in type 2 diabetes patients.

In this study, we examined the effects of green tea on inflammation and arterial stiffness in type 2 diabetes patients. As results, inflammatory markers, such as hsCRP and IL-6, were unchanged after green tea consumption, and neither were blood glucose, lipid profiles, insulin resistance, or serum adiponectin levels. Furthermore, tea consumption did not improve baPWV. These results suggest that the above-described mechanisms are unlikely to explain the cardiovascular risk reduction by tea consumption observed in epidemiological studies.

Beverages↗

Salvage chemotherapy with irinotecan, 5-fluorouracil and leucovorin for taxane- and cisplatin-refractory, metastatic gastric cancer.

We performed a phase II study of combination chemotherapy with irinotecan, 5-fluorouracil (5-FU) and leucovorin in metastatic gastric cancer patients who were previously treated with taxane and cisplatin, to evaluate the antitumour activity and toxicity of the combination chemotherapy. The metastatic gastric adenocarcinoma patients who were previously treated with taxane and cisplatin combination as first line, and had at least one measurable lesion, 0-2 ECOG performance status and adequate organ functions, were considered eligible. They received irinotecan (150 mg m(-2), day 1) and leucovorin (100 mg m(-2), day 1), followed by continuous infusion of 5-FU (1000 mg m(-2) day(-1), days 1 and 2) every 2 weeks. Treatment was continued until progression of disease was observed. In all, 64 patients were treated with this combination chemotherapy. The median age of the patients was 55 years (range, 33-74 years), and the median ECOG performance status was 1 (0-1, 61 (95%)). Out of 64 patients, 57 were assessable for response. Among 57 assessable patients, no complete response and 12 partial responses were observed (overall response rate, 21%; 95% confidence interval (CI), 10-32%). Stable disease was observed in 14 patients (25%) and progressive disease in 31 patients (54%). The median time to progression was 2.5 months (95% CI, 1.6-3.4) and the median overall survival since the start of the second-line modified FOLFIRI was 7.6 months (95% CI, 6.5-8.7). Grade 3-4 haematologic toxicities included neutropenia in seven patients (11%) and thrombocytopenia in five patients (8%). Grade 3-4 nonhaematologic toxicities included diarrhoea in two patients (3%) and vomiting in two patients (3%). There were no treatment-related deaths. The combination of irinotecan, 5-FU and leucovorin showed moderate activity and favourable toxicity profile as a second-line treatment in metastatic gastric cancer patients, who were previously treated with taxane and cisplatin.

Adenocarcinoma↗

Coincidence of checkerboard charge order and antinodal state decoherence in strongly underdoped superconducting Bi2Sr2CaCu2O8 + delta).

The doping dependence of nanoscale electronic structure in superconducting Bi(2)Sr(2)CaCu(2)O(8 + delta) is studied by scanning tunneling microscopy. At all dopings, the low energy density-of-states modulations are analyzed according to a simple model of quasiparticle interference and found to be consistent with Fermi-arc superconductivity. The superconducting coherence peaks, ubiquitous in near-optimal tunneling spectra, are destroyed with strong underdoping and a new spectral type appears. Exclusively in regions exhibiting this new spectrum, we find local "checkerboard" charge ordering of high energy states, with a wave vector of Q = (+/- 2pi/4.5a(0),0); (0, +/- 2pi/4.5a(0)) +/- 15%. Surprisingly, this spatial ordering of high energy states coexists harmoniously with the low energy Bogoliubov quasiparticle states.

Journal Article↗

Improved measurement of the form factors in the decay lambda+c-->lambda + nue.

Using the CLEO detector at the Cornell Electron Storage Ring, we have studied the distribution of kinematic variables in the decay lambda(+)(c)lambda--> e(+)nu(e). By performing a four-dimensional maximum likelihood fit, we determine the form factor ratio, R= f(2)/f(1) = -0.31 +/- 0.05(stat) +/- 0.04(syst), the pole mass, M(pole) = [2.21 +/- 0.08(stat) +/- 0.14(syst)] GeV/c(2), and the decay asymmetry parameter of the lambda(+)(c), alpha (lambda(c)) = -0.86 +/-0.03(stat) +/- 0.02(syst), for q(2) = 0.67 (GeV/c(2))(2). We compare the angular distributions of the lambda(+)(c) and lambda(-)(c) and find no evidence for CP violation: A(lambda(c)) = (alpha(lambda(c)) + alpha (lambda(c)))/(alpha(lambda(c))-alpha(lambda(c))) = 0.00 +/- 0.03(stat) +/- 0.01(syst) +/- 0.02, where the third error is from the uncertainty in the world average of the CP-violating parameter, A(lambda), for ppi(-).

Journal Article↗

Nasal-type NK/T cell lymphoma: clinical features and treatment outcome.

Nasal-type NK/T cell lymphoma is an increasingly recognised disease entity of aggressive clinical behaviour. The objective of this study was to investigate clinical features and treatment outcomes in patients with nasal-type NK/T cell lymphoma. From January 1991 to December 2003, 26 patients diagnosed as nasal-type NK/T cell lymphoma were included in the analysis. One half of patients presented with poor performance status (ECOG > or =2); 46% of patients were categorised as high intermediate or high-risk group according to IPI; and 46% of patients were diagnosed at advanced stage. The median survival for 26 patients with nasal-type NK/T cell lymphoma was 7.4 months (95% CI, 0.1, 16.9). The treatment outcome of primary anthracycline-based chemotherapy was poor: 60% CR rate in localised disease and 0% CR rate in advanced disease. After a median follow-up of 24.4 months (range 3.1-99.0) in patients with localised disease who had achieved a CR (range 29.6-165.7), three patients (50.0%) developed disease recurrence at 6.1, 21.8, and 52.1 months, respectively, and all patients presented with locoregional failure. The predictive factors for poor survival were of age greater than 60, advanced stage and poor performance in multivariate analysis. In conclusion, Nasal-type NK/T cell lymphomas showed a poor response to the conventional anthracycline-based chemotherapy, and thus an investigation for an innovative therapy is urgently needed to improve survival in these patients.

Adult↗

Measurement of estrogen effect on bone turnover by 2H2O labeling.

Estrogen loss has been known to increase bone turnover through accelerated bone resorption coupled by increased bone formation. In the present study, we measured estrogen effect on bone turnover by incorporation of 2H from 2H2O into amino acids. At 6 weeks of age, rats were either sham-operated (sham) or ovariectomized (ovx). Two weeks after surgery, 17beta-estradiol (est) was implanted subcutaneously to ovx rats. At 9 weeks of age, 2H2O labeling started by administration of 4% 2H2O to rats for 4 or 7 weeks in drinking water after a single intraperitonial bolus injection with 99.9% 2H2O. Body 2H2O enrichments were stable at approximately 3.0% over labeling period. Fractional replacements (f) of the midshaft femur were higher in the sham group (40.36 +/- 4.89% vs 42.47 +/- 11.22%) than the ovx (28.57 +/- 9.67% vs 37.47 +/- 8.34%) and est (26.57 +/- 4.00% vs 30.35 +/- 5.34%) groups 4 and 7 weeks after labeling, respectively. Ovariectomy-induced bone loss was observed in the trabecular bone along with a significantly increased number of osteoclasts, all of which were normalized after estradiol treatment. Taken together, our results indicate that estrogen deficiency significantly reduces the proportion of newly synthesized bone matrix as well as the total amount of bone matrix. The reduced portion of new matrix in ovx rats, presumably caused by activated osteoclastic degradation, was compensated rapidly with time. In addition, estradiol treatment protected the bone matrix by decreasing bone turnover rate.

Alanine↗

A new drug carrier, Nalpha-deoxycholyl-L: -lysyl-methylester, for enhancing insulin absorption in the intestine.

AIMS/HYPOTHESIS: The development of an orally active insulin formulation will offer great advantages over conventional injectable insulin therapy in the treatment of patients with diabetes mellitus. Since insulin absorption in the intestine is restricted by the natural physiological characteristics of insulin, we developed a small synthetic compound, Nalpha-deoxycholyl-L: -lysyl-methylester (DCK), as an insulin carrier to enhance oral delivery. METHODS: Streptozotocin-induced diabetic rats orally received single doses of insulin (42 U/kg) or insulin/DCK formulation (10, 21, 30 and 42 U/kg) under fasting conditions. Blood glucose levels and plasma insulin concentrations were measured for 6 h following the administration of the agents. An OGTT was also performed immediately after the administration of the oral insulin/DCK formulation. RESULTS: The administration of 21, 30 and 42 U/kg (based on insulin activity) of insulin/DCK formulation reduced plasma glucose levels by up to 33.0% (median; range 30.6-70.2%), 78.5% (39.4-86.8%) and 75.2% (67.0-87.4%), respectively, compared with baseline levels. Furthermore, plasma insulin concentrations were observed to rapidly increase. In the OGTT, the insulin/DCK formulation reduced the AUC0-240 for glucose by 30.8% (22.3-54.9%) (p<0.01), and stabilized glycaemia for up to 4 h. CONCLUSIONS/INTERPRETATION: The results of this study demonstrate that the insulin/DCK formulation can be absorbed in the intestine and that it is biologically efficacious. We therefore suggest that this oral formulation could be used as an alternative to injectable insulin with enhanced clinical effects.

Animals↗

Down syndrome with pure partial trisomy 21q22 due to a paternal insertion (4;21) uncovered by uncultured amniotic fluid interphase FISH.

OBJECTIVE: To emphasize the usefulness and reliability of fluorescence in situ hybridization (FISH) on uncultured amniotic fluid cells in the prenatal diagnosis of common chromosomal aneuploidies. METHODS: FISH analyses utilizing centromeric, locus-specific or whole chromosome paint DNA probes specific for chromosomes X, Y, 13, 18, 21, and 4 were performed on uncultured amniotic fluid cells or the peripheral blood specimen from the father. Routine chromosome analysis was carried out as well. RESULTS: A prenatal case with partial trisomy 21 due to a paternal cryptic insertion (4;21) was ascertained by a rapid overnight FISH on uncultured amniotic fluid cells. The fetus was delivered at term and had classical features of Down syndrome. CONCLUSION: Our results stress the importance of FISH on uncultured amniotic fluid cells to supplement routine cytogenetics, especially in cases with abnormal ultrasound findings.

Adult↗

Smaller inner ear sensory epithelia in Neurog 1 null mice are related to earlier hair cell cycle exit.

We investigated whether co-expression of Neurog 1 and Atoh 1 in common neurosensory precursors could explain the loss of hair cells in Neurog 1 null mice. Analysis of terminal mitosis, using BrdU, supports previous findings regarding timing of exit from cell cycle. Specifically, we show that cell cycle exit occurs in spiral sensory neurons in a base-to-apex progression followed by cell cycle exit of hair cells in the organ of Corti in an apex-to-base progression, with some overlap of cell cycle exit in the apex for both hair cells and spiral sensory neurons. Hair cells in Neurog 1 null mice show cell cycle exit in an apex-to-base progression about 1-2 days earlier. Atoh 1 is expressed in an apex-to-base progression rather then a base-to-apex progression as in wildtype littermates. We tested the possible expression of Atoh1 in neurosensory precursors using two Atoh 1-Cre lines. We show Atoh 1-Cre mediated beta-galactosidase expression in delaminating sensory neuron precursors as well as undifferentiated epithelial cells at E11 and E12.5. PCR analysis shows expression of Atoh 1 in the otocyst as early as E10.5, prior to any histology-based detection techniques. Combined, these data suggest that low levels of Atoh 1 exist much earlier in precursors of hair cells and sensory neurons, possibly including neurosensory precursors. Analysis of Atoh 1-Cre expression in E18.5 embryos and P31 mice reveal beta-galactosidase stain in all hair cells but also in vestibular and cochlear sensory neurons and some supporting cells. A similar expression of Atoh 1-LacZ exists in postnatal and adult vestibular and cochlear sensory neurons, and Atoh 1 expression in vestibular sensory neurons is confirmed with RT-PCR. We propose that the absence of NEUROG 1 protein leads to loss of sensory neuron formation through a phenotypic switch of cycling neurosensory precursors from sensory neuron to hair cell fate. Neurog 1 null mice show a truncation of clonal expansion of hair cell precursors through temporally altered terminal mitosis, thereby resulting in smaller sensory epithelia.

Animals↗

Cytokine polymorphisms do not influence acute rejection in renal transplantation under tacrolimus-based immunosuppression.

INTRODUCTION: Acute rejection remains an important cause of graft loss after renal transplantation. It has been suggested that cytokine genotyping may play a predictive role in identifying individuals who are at higher risk of acute rejection with a view to individualizing their immunosuppression. The aim of this study was to investigate any possible associations between acute rejection and certain cytokine polymorphisms. METHODS: We genotyped 91 cadaveric renal transplant recipients on tacrolimus-based immunosuppression and 84 of their donors. The cytokine polymorphisms studied were the following: tumor necrosis factor (TNF)-alpha-1032 T/C, TNF-alpha-865 C/A, TNF-alpha-859 G/A, interleukin (IL)1-R1-970 C/T, IL-10 haplotype [-1082, -819, -592], and IL-6-174 C/G. RESULTS: We found no association between any polymorphism and the incidence of acute rejection. This was true for both the recipient and donor population. CONCLUSION: Cytokine polymorphisms did not influence acute rejection in our study. We conclude that in the modern era of immunosuppression cytokine genotyping is not a significant predictor of acute rejection in renal transplantation.

Adult↗

ESHAP plus G-CSF as an effective peripheral blood progenitor cell mobilization regimen in pretreated non-Hodgkin's lymphoma: comparison with high-dose cyclophosphamide plus G-CSF.

The ESHAP (etoposide, methylprednisolone, high-dose cytarabine, and cisplatin) regimen has been shown to be effective as an active salvage therapy for lymphoma. Mobilizing stem cells following ESHAP should decrease time to transplantation by making separate mobilizing chemotherapy (MC) unnecessary, while controlling a patient's lymphoma. We therefore assessed the mobilization potential of ESHAP plus G-CSF in 26 patients (ESHAP group) with non-Hodgkin's lymphoma (NHL) and compared these results with those of 24 patients with NHL who received high-dose (4 g/m2l) cyclophosphamide (HDCY) as MC (HDCY group). The age, sex, and radiotherapy to the axial skeleton were well matched between groups, but the number of patients with poor mobilization predictors was higher in the ESHAP group. Significantly higher numbers of CD34+ cells (x 10(6)/kg) (17.1+/-18.8 vs 5.8+/-5.0, P=0.03) and apheresis day 1 CD34+ cells (x 10(6)/kg) (5.5+/-6.6 vs 1.7+/-2.0, P=0.014) were collected from the ESHAP group than from the HDCY group, and the number of patients who achieved an optimal CD34+ cell target of 5 x 10(6)/kg was higher in the ESHAP group (81 vs 50%, P=0.022). Log-rank test revealed that time to target peripheral blood progenitor cell collection (> or =5 x 10(6)/kg) was shorter in the ESHAP group (P=0.007). These results indicate that ESHAP plus G-CSF is an excellent mobilization regimen in patients with relapsed and poor-risk aggressive NHL.

Adolescent↗

Selective enzymatic cleavage of gold nanoparticle-labelled DNA on a microarray.

The use of the restriction enzyme EcoRI for the manipulation of double-stranded DNA on microarrays is introduced. Gold nanoparticles are attached to a microarray via base pairing between complementary DNA sequences on the array and on the particles. These particles could be detected by light scattering measurements following an enhancement step, in which silver islands were deposited on top of the gold particles. This deposition of silver could be completely suppressed if the particles were removed by enzymatic cleavage of their DNA linker molecules. This cleavage step critically depends on the presence of a specific enzyme recognition site.

Coated Materials, Biocompatible↗

Identification of glutathione conjugates and mercapturic acids of 1,2-dibromopropane in female BALB/c mice by liquid chromatography-electrospray ionization tandem mass spectrometry.

Based on recent results that 1,2-dibromopropane (1,2-DBP) causes hepatotoxicity and immunotoxicity in female BALB/c mice as well as a reduction of hepatic glutathione levels, the possible formation of glutathione conjugates and mercapturic acids of 1,2-DBP was investigated in vivo in the present studies. The following four metabolites were identified in the liver at 12 h after treatment with 1,2-DBP, by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI/MS): M1, 2-hydroxypropylglutathione; M2, 2-oxopropylglutathione; M3, N-acetyl-S-(2-hydroxypropyl)-L-cysteine; and M4, N-acetyl-S-(2-oxopropyl)-L-cysteine. Ions of individual conjugates were observed at m/z 366, 364, 222 and 220, respectively. Characteristic product ions at m/z 237, 217, 204 and 202 for the identification of M1, M2, M3 and M4 were observed, respectively. In the sera isolated from the same animals, only mercapturic acids (M3 and M4) were observed by LC-ESI/MS. When female BALB/c mice were treated orally with 1,2-DBP at doses of 150, 300 and 600 mg kg(-1) once for 12 h, the production of glutathione conjugates and mercapturic acids in liver was apparently dose dependent, as were the concentrations of them in sera. When the production of metabolites from 1,2-DBP was investigated in liver following oral treatment with 600 mg kg(-1) 1,2-DBP for 6, 12, 24 and 48 h, metabolite concentrations were greatest at the first time point (6 h). The results explain the authors' previous studies that oral treatment with 1,2-DBP reduces the hepatic content of glutathione.

Acetylcysteine↗

IMVP-16/Pd followed by high-dose chemotherapy and autologous stem cell transplantation as a salvage therapy for refractory or relapsed peripheral T-cell lymphomas.

The present study aimed to analyse the treatment outcome of IMVP-16/Pd (ifosfamide, methotrexate, etoposide and prednisone) followed by high-dose chemotherapy and autologous stem cell transplantation (HDC/ASCT) for patients with peripheral T-cell lymphomas (PTCLs) who were previously treated with CHOP. Since 1995, 32 PTCL patients were treated with IMPV-16/Pd. Nine of 32 patients achieved a response (5 demonstrating complete response (CR) and 4 partial response), with an overall response rate of 28.1% (95% onfidence interval 0.12-0.45). Considering histopathologic subtypes, 3 of 4 relapsed natural killer (NK)/T-cell lymphoma patients (75%) achieved CR, but only 1 of 6 in non-NK/T-cell lymphoma patients (16.7%) achieved CR (P = 0.19). Six of 9 IMVP-16/Pd sensitive patients underwent HDC/ASCT. Three of them relapsed after 3, 4 and 15 months, respectively, of HDC/ASCT. Estimated 3-year overall survival and progression-free survival rates were 14.2% and 12.2%, respectively. Multivariate analysis revealed that responsiveness to first-line CHOP was a significant prognostic factor (P < 0.05). These results indicate that IMVP-16/Pd followed by HDC/ASCT appears to be an effective salvage regimen, especially for NK/T-cell lymphoma.

Adolescent↗

Chlamydia pneumoniae infection enhances cellular proliferation and reduces steroid responsiveness of human peripheral blood mononuclear cells via a tumor necrosis factor-alpha-dependent pathway.

BACKGROUND: Although epidemiological studies have found an association between Chlamydia pneumoniae infection and severe asthma, the causality and underlying mechanism are largely unknown. We hypothesized that C. pneumoniae infection increases the proliferation and enhances the survival of immune and inflammatory cells, resulting in reduced responsiveness to corticosteroids and suggesting that the underlying mechanism is related to a TNF-alpha-dependent pathway. METHODS: Human peripheral blood mononuclear cells (PBMCs) were cultured in vitro in the presence or absence of C. pneumoniae infection. Responsiveness to corticosteroids was assayed by adding dexamethasone, and the underlying mechanism was investigated by treating cells with infliximab that is a chimeric anti-TNF-alpha monoclonal antibody. Cellular proliferation and apoptosis was assessed by thymidine uptake and counting apoptotic cells using flow cytometry. RESULTS: Cellular proliferation was significantly higher in C. pneumoniae-infected PBMCs than in uninfected PBMCs, which is more prominent in Th2-dominant microenvironment. The anti-proliferative and pro-apoptotic effect of corticosteroid were significantly reduced in C. pneumoniae-infected PBMCs compared with uninfected PBMCs. The proliferative effect of C. pneumoniae infection and the reduced response to corticosteroid were effectively reversed by blocking the TNF-alpha pathway at least partially. CONCLUSION: C. pneumoniae infection enhanced the proliferation and survival of immune and inflammatory cells, resulting in steroid resistance. The reversal of these phenomena by the TNF-alpha inhibitor suggests that TNF-alpha may play an important role in the induction of steroid dependence or resistance. A TNF-alpha inhibitor may therefore be a candidate agent for managing steroid-dependent or -resistant severe asthma.

Adrenal Cortex Hormones↗

Serum osteoprotegerin levels are associated with inflammation and pulse wave velocity.

OBJECTIVE: We examined the association between serum osteoprotegerin (OPG) levels, systemic inflammation and arterial stiffness in normal and diabetic patients. PATIENTS AND MEASUREMENTS: The study subjects comprised 49 newly diagnosed diabetic patients and 72 age- and sex-matched normal glucose controls. Anthropometric parameters, blood pressure, fasting blood glucose (FBG), lipid profiles, serum OPG, high-sensitive C-reactive protein (hsCRP), interleukin-6 (IL-6) and brachial-ankle pulse wave velocity (baPWV) were measured. RESULTS: Serum OPG levels (6.1 +/- 1.4 vs. 5.4 +/- 1.3 pmol/l, P = 0.011) and baPWV (1562 +/- 354 vs. 1399 +/- 257 cm/s, P = 0.004) were significantly higher in the diabetic group than in the normal glucose group. Serum OPG levels in normal and diabetic patients correlated significantly with systolic blood pressure (r = 0.20, P = 0.035), FBG (r = 0.30, P = 0.002), right baPWV (r = 0.22, P = 0.021), left baPWV (r = 0.26, P = 0.006), homeostasis model assessment insulin resistance (HOMA-IR) (r = 0.19, P = 0.045), IL-6 (r = 0.32, P = 0.001) and hsCRP (r = 0.21, P = 0.027) after adjusting for age and sex. Multiple regression analysis showed that serum OPG level was significantly associated with age, FBG, IL-6, systolic blood pressure, triglyceride and hsCRP (R(2) = 0.299). CONCLUSIONS: In summary, serum OPG and baPWV levels are elevated in diabetic patients and serum OPG levels are significantly associated with inflammation and arterial stiffness.

Biomarkers↗