Biomedical subjects

M Huang

Publications and source records attributed to M Huang.

At least 37 records · Page 2Linked to original sources

PubMed2005

A novel locus for autosomal dominant hereditary gingival fibromatosis, GINGF3, maps to chromosome 2p22.3-p23.3.

Hereditary gingival fibromatosis (HGF) is a rare, benign disorder characterized by slowly progressive fibrous overgrowth of the gingiva. To date, two loci have been mapped in familial cases with autosomal dominant non-syndromic HGF: GINGF (MIM 135300) on chromosome 2p21-p22 and GINGF2 (MIM 605544) on chromosome 5q13-q22. Of the two loci, only SOS1 (son of sevenless one, MIM 182530) gene underlying GINGF locus has been identified. Ascertainment of a large Chinese family has allowed the mapping of a novel locus to 2p22.3-p23.3, GINGF3. Haplotype construction and analysis localized the new locus to an 11.4-cM interval between markers D2S2221 (telomeric) and D2S1788 (centromeric). The maximum two-point limit of detection (LOD) score of 3.45 (theta=0) and multipoint LOD score of 5.00 for marker D2S390 strongly supported linkage to this region. Thus, this genetic interval is distal to and does not overlap with the previously described locus, GINGF, on 2p21-p22.

Asian People↗

PubMed2005

RS3PE syndrome presenting as vascular endothelial growth factor associated disorder.

OBJECTIVES: To characterise serum concentrations of various cytokines and detection by magnetic resonance imaging (MRI) of synovial hypervascularity in patients with remitting seronegative symmetrical synovitis with pitting oedema (RS3PE) syndrome before and after corticosteroid treatment. METHODS: Vascular endothelial growth factor(165) (VEGF(165)), tumour necrosis factor alpha (TNFalpha), and interleukin 1beta (IL1beta) were measured by enzyme linked immunosorbent assay (ELISA) in serum samples from three patients with RS3PE syndrome. As controls, serum samples from 26 healthy volunteers, 12 patients with rheumatoid arthritis, 10 patients with systemic lupus erythematosus, 13 patients with polymyositis/dermatomyositis, 13 patients with vasculitis syndrome, and 6 patients with mixed connective tissue disease were also analysed. Synovial hypervascularity of patients with RS3PE syndrome was estimated by rate of enhancement (E-rate) in a dynamic MRI study. RESULTS: Serum concentrations of VEGF(165) (mean (SD) 2223.3 (156.3) pg/ml) were significantly higher in patients with active RS3PE syndrome than in controls before corticosteroid treatment. TNFalpha and IL1beta levels were similar in patients and controls. Synovial hypervascularity in affected joints and subcutaneous oedema decreased during corticosteroid treatment, in parallel with the fall in serum VEGF(165). CONCLUSIONS: VEGF promotes synovial inflammation and vascular permeability in patients with RS3PE syndrome, suggesting that RS3PE can be classified as a VEGF associated disorder.

Adrenal Cortex Hormones↗

PubMed2004

Search for CP violation in charged-Xi and Lambda hyperon decays.

We have compared the p and p angular distributions in 117 x 10(6) Xi- -->Lambdapi- -->ppi-pi- and 41 x 10(6) Xi+ -->Lambda pi+ -->p pi+pi+ decays using a subset of the data from the HyperCP experiment (E871) at Fermilab. We find no evidence of CP violation, with the direct-CP-violating parameter AXiLambda identical with (alphaXialphaLambda-alpha Xialpha Lambda)/(alphaXialphaLambda+alphaXialphaLambda)=[0.0+/-5.1(stat)+/-4.4(syst)] x 10(-4).

Journal Article↗

PubMed2004

Auditory sensory gating deficit and cortical thickness in schizophrenia.

Both an EEG P50 sensory gating deficit and abnormalities of the temporal lobe structure are considered characteristic of schizophrenia. The standard P50 sensory gating measure does not foster differential assessment of left- and right-hemisphere contributions, but its analogous MEG M50 component may be used to measure gating of distinct auditory source dipoles localizing to left- and right-hemisphere primary auditory cortex. The present study sought to determine how sensory gating ratio may relate to cortical thickness at the site of the auditory dipole localization. A standard auditory paired-click paradigm was used during MEG for patients (n=22) and normal controls (n=11). Sensory gating ratios were determined by measuring the strength of the 50 ms response to the second click divided by that of the first click (S2/S1). Cortical thickness was assessed by two reliable raters using 3D sMRI. Results showed that: (1) patients had a P50 and left M50 sensory gating deficit relative to controls; (2) cortex in both hemispheres was thicker in the control group; (3) in schizophrenia, poorer left-hemisphere M50 sensory gating correlated with thinner left-hemisphere auditory cortical thickness; and (4) poorer right-hemisphere M50 auditory sensory gating ratio correlated with thinner right-hemisphere auditory cortical thickness in patients. The MEG-assessed hemisphere-specific auditory sensory gating ratio may be driven by this structural abnormality in auditory cortex.

Acoustic Stimulation↗

PubMed2004

A novel mutation (T61I) in the gene encoding tumour necrosis factor receptor superfamily 1A (TNFRSF1A) in a Japanese patient with tumour necrosis factor receptor-associated periodic syndrome (TRAPS) associated with systemic lupus erythematosus.

OBJECTIVE: To identify potential mutations in the tumour necrosis factor receptor superfamily 1A gene (TNFRSF1A) in a Japanese female patient with recurrent fever complicated by systemic lupus erythematosus (SLE), and in her family members. METHODS: DNA sequencing of exons 1-10 of the TNFRSF1A gene was performed to determine mutations that might be associated with the tumour necrosis factor receptor-associated periodic syndrome (TRAPS). Moreover, the TNFRSF1A gene was examined in Japanese patients with autoimmune diseases, including SLE, rheumatoid arthritis (RA), mixed connective tissue disease (MCTD) and Behçet's disease, and in healthy Japanese controls. Enzyme-amplified sensitivity immunoassay (EASIA) analysis was used to assess serum levels of TNF, the 55-kDa TNF receptor (TNFRSF1A) and the 75-kDa TNF receptor (TNFRSF1B). Membrane TNFRSF1A expression was analysed on the surface of peripheral blood mononuclear cells by flow cytometry. RESULTS: A novel mutation, a heterozygous C to T transition in exon 3 which substitutes an isoleucine for a threonine at position 61 (T61I) was detected in the TNFRSF1A gene derived from the genomic DNA of a Japanese female TRAPS patient. Two nieces and one nephew, all with a similar clinical phenotype, also possessed the same TNFRSF1A mutation. We further demonstrated the same mutation in five of 60 SLE patients (8.3%) and in five of 120 healthy individuals (4.2%), with no significant differences. Although high titres of serum TNF and soluble TNFRSF1B protein were observed in this patient, low titres of soluble TNFRSF1A protein were detected. However, a defect in TNFRSF1A shedding in vitro was not observed in monocytes derived from this patient. CONCLUSION: This is the first report of a TRAPS patient associated with SLE with a novel TNFRSF1A mutation (T61I).

Adolescent↗

PubMed2004

MEG response to median nerve stimulation correlates with recovery of sensory and motor function after stroke.

OBJECTIVE: Hemiparesis due to damage by stroke in primary motor cortex (MI) or its underlying projections presents a problem for functional neuroimaging technologies that attempt to evaluate the neurophysiological basis for restoration of motor function. Traditional assessments of MI function require patients to move their fingers, hands, or limbs, which can be either impossible or markedly compromised after stroke. We recently demonstrated in normal subjects that magnetoencephalography (MEG), a non-invasive neuromagnetic functional imaging technique, detects neuronal response elicited by electrical median nerve stimulation in MI, as well as primary somatosensory cortex (SI). In the present study, we used the MEG response from median nerve stimulation to investigate the recovery of primary motor and somatosensory in acute ischemic stroke patients. METHODS: Twelve patients with unilateral ischemic strokes that affected sensorimotor functions of their hand were studied in the acute stage (4.4+/-1.2 days, mean+/-SD) and during a 1-month follow-up (38.6+/-5.6 days, except for one patient's follow-up done 6 month after stroke). RESULTS: Among the multiple cortical sources localized after median nerve stimulation, one source localized to SI and another localized to the vicinity of MI. Changes in the source strengths of the first component post-stimulus of MI and SI correlated with the extent of recovery of sensorimotor functions as determined by neurological exams. CONCLUSIONS: This study provides a novel way of indirectly assessing MI function using MEG during the acute stroke phase, when many patients often cannot perform motor tasks due to paralysis.

Adult↗

PubMed2004

Death with graft function in elderly patients after cadaveric renal transplantation: effect of waiting time.

Survival after kidney transplantation is better than on the waiting list, even in the elderly. However, the effects of a prolonged waiting time for an organ on death with graft function have not been critically examined in this patient group. We conducted a single-center retrospective analysis of our cadaveric renal transplant experience in patients older than 60 years who received a kidney between January 1, 1990 and December 31, 2003. Besides waiting time, the effects of recipient age, gender, and diabetes were also examined. Cox proportional hazards analysis using patient death as a time-dependent outcome was used to estimate the hazard ratio of death posttransplantation. Using Kaplan-Meier survival methodology, patients with waiting times < or =5 years had significantly better survival times posttransplantation compared with those with waiting times >5 years (6.2 vs 2.8 years; P <.001). Each year of waiting was associated with hazard ratio 1.16 (95% confidence interval [CI], 1.06-1.27) for death. Prolonged waiting time on dialysis is deleterious to patient survival in recipients older than 60 years at transplantation. Early transplantation thus should be strongly encouraged in this group of patients.

Age Factors↗

PubMed2004

CPEC induces erythroid differentiation of human myeloid leukemia K562 cells through CTP depletion and p38 MAP kinase.

Cyclopentenyl cytosine (CPEC) is a carbocyclic cytidine analog inhibitor of CTP synthetase and experimental drug for combination chemotherapy. CPEC treatment (50 nM) depleted intracellular CTP and induced a specific S-phase arrest and erythroid differentiation of human erythroleukemia K562 cells. The equilibrative nucleoside transporters (ENT1, 2) facilitated uptake of CPEC into K562 cells as evidenced by both NBMPR and dipyridamole inhibition of CPEC-mediated CTP depletion and erythroid differentiation. Incubation with the pyridinylimidazole p38 MAPK inhibitors, SB203580 or SB220025, suppressed both the CPEC-induced cell cycle arrest and differentiation of K562 cells. SB203580 also prevented the cell cycle arrest and erythroid differentiation of K562 cells induced by Leflunomide (LEF), a non-nucleoside inhibitor of the de novo pyrimidine pathway, without affecting LEF-induced depletion of pyrimidine pools. Finally, selective knockdown of p38 MAPK by using Smart Pooltrade mark siRNA to p38 MAPK significantly decreased the CPEC-induced differentiation of K562 cells. These results suggest that endogenous activity of p38 MAP kinases may be required for committing K562 cells to cell cycle arrest and erythroid differentiation under conditions of CTP depletion.

Affinity Labels↗

PubMed2004

Randomized, double-blind placebo controlled trial of the once daily antimuscarinic agent solifenacin succinate in patients with overactive bladder.

PURPOSE: In this phase 3 trial we assessed the efficacy of solifenacin 5 mg and 10 mg daily in patients with symptoms related to overactive bladder. In addition, we assessed the safety and acceptability of solifenacin. MATERIALS AND METHODS: The study was a multicenter, multinational, randomized, double-blind, placebo controlled trial. Patients were randomized to 12-week once daily treatment with solifenacin 5 mg, solifenacin 10 mg or placebo. The primary efficacy variable was changed from baseline to study end point in mean number of micturitions per 24 hours. Secondary efficacy variables included changes from baseline in mean number of urgency, nocturia and incontinence episodes per 24 hours, and mean volume voided per micturition. RESULTS: Compared with changes obtained with placebo (-1.59), micturitions per 24 hours were statistically significantly decreased with solifenacin 5 mg (-2.37, p = 0.0018) and solifenacin 10 mg (-2.81, p = 0.0001). A statistically significant decrease was observed in the number of incontinence episodes with both solifenacin doses (5 mg, p = 0.002 and 10 mg, p = 0.016). This effect was also seen for episodes of urge incontinence (5 mg, p = 0.014 and 10 mg, p = 0.042). Of patients reporting incontinence at baseline, fully 50% achieved continence after treatment with solifenacin. Episodes of nocturia were statistically significantly decreased in patients treated with solifenacin 10 mg (-0.71, -38.5%) versus placebo (-0.52, -16.4%, p = 0.036). Episodes of urgency were statistically significantly reduced with solifenacin 5 mg (-2.84, -51%, p = 0.003) and solifenacin 10 mg (-2.90, -52%, p = 0.002). Mean volume voided per micturition was statistically significantly increased with both solifenacin doses (p = 0.0001). Treatment with solifenacin was well tolerated. Dry mouth, mostly mild in severity, was reported in 7.7% of patients receiving solifenacin 5 mg and 23% receiving solifenacin 10 mg (vs 2.3% with placebo). CONCLUSIONS: In this study treatment with solifenacin 5 mg and 10 mg once daily significantly improved all the major symptoms of overactive bladder including frequency, urgency and incontinence. Solifenacin 10 mg also decreased the frequency of nocturia. Solifenacin therapy was associated with a favorable tolerability profile and a low incidence of dry mouth, especially at the 5 mg starting dose.

Adolescent↗

PubMed2004

Randomized, double-blind placebo- and tolterodine-controlled trial of the once-daily antimuscarinic agent solifenacin in patients with symptomatic overactive bladder.

OBJECTIVE: To assess in a phase 3a trial the efficacy of solifenacin succinate, a once-daily oral antimuscarinic agent in development at 5-mg and 10-mg dosage strengths, for the treatment of overactive bladder (OAB) (Yamanouchi Pharmaceutical Co. Ltd, Tokyo, Japan) compared with placebo in patients with symptoms of OAB, i.e. urgency, incontinence, and frequency, with additional objectives being to assess the safety and tolerability of solifenacin and to compare the efficacy and safety of solifenacin with tolterodine 2 mg twice daily. PATIENTS AND METHODS: The study was an international, multicentre, randomized, double-blind, tolterodine- and placebo-controlled trial conducted at 98 centres. Adult patients with symptomatic OAB for > or = 3 months were eligible; after a single-blind 2-week placebo run-in period patients were randomized equally to a 12-week double-blind treatment with either tolterodine 2 mg twice daily, placebo, solifenacin 5 mg or 10 mg once daily. Efficacy variables included change from baseline in the mean number of urgency, incontinence and urge incontinence episodes, and change from baseline in voids/24 h and mean volume voided/void. RESULTS: In all, 1281 patients were enrolled, 1081 randomized and 1077 treated; 1033 were evaluated for efficacy. Compared with placebo, the change from baseline (-1.41, -32.7%) in the mean number of urgency episodes per 24 h was statistically significantly lower with solifenacin 5 mg (-2.85, -51.9%) and 10 mg (-3.07, -54.7%; both P < 0.001), but not with tolterodine (-2.05, -37.9%; P = 0.0511). There was a statistically insignificant decrease in episodes of incontinence with tolterodine (-1.14; P = 0.1122) but a significant decrease in patients treated with solifenacin 5 (-1.42; P = 0.008) and 10 mg (-1.45; P = 0.0038). Compared with placebo (-1.20, -8.1%) the mean number of voids/24 h was significantly lower in patients receiving tolterodine (-1.88, -15%; P = 0.0145), solifenacin 5 (-2.19, -17%) and 10 mg (-2.61, -20%; both P < 0.001). The mean volume voided/void was also significantly higher with all three active treatments (P < 0.001). Solifenacin was well tolerated; compared with placebo (4.9%), dry mouth (the most common side-effect), mostly mild, was reported in 18.6% of patients receiving tolterodine, 14.0% receiving 5 mg and 21.3% receiving 10 mg solifenacin. CONCLUSION: Solifenacin 5 and 10 mg once daily improved urgency and other symptoms of OAB, and was associated with an acceptable level of anticholinergic side-effects. Solifenacin demonstrated significantly favourable efficacy to side-effect ratio in treating symptomatic OAB.

Administration, Oral↗

PubMed2003

Thermal stresses in optical waveguides.

Birefringence of optical waveguides is closely related to the anisotropy of thermal stresses in the core. Closed-form solutions for estimating the thermal stresses in the cladding layers and in the core of an embedded channel waveguide are presented. The solutions are verified by finite-element simulation. It is found that the thermal stress in the core in the direction perpendicular to the wafer cannot be ignored, and one can tune the core stress anisotropy in the plane normal to the light-propagation direction by varying the thermal-expansion mismatch between the upper cladding and the substrate.

Journal Article↗

PubMed2003

Ultrasonication of chitosan and chitosan nanoparticles.

The objective of this study was to evaluate the effects of ultrasonication on chitosan molecules and nanoparticles. Molecular weight (M(v)) of chitosan HCl (M(v) 146 kDa and degree of deacetylation (DD) 96%) decreased linearly with increasing duration and amplitude of ultrasonication. DD and FTIR absorption were unaffected. X-ray diffraction (XRD) analysis suggested greater chain alignment in the ultrasonicated chitosan samples. Chitosan nanoparticles had mean diameter of 382 nm, polydispersity of 0.53 and zeta potential of 47 mV. Ultrasonication administered at increasing duration or amplitude decreased the mean diameter and polydispersity of the nanoparticles. Zeta potential and FTIR absorbance were unaffected, while XRD suggested a greater disarray of chain alignment in the nanoparticle matrix. Under the transmission electron microscope (TEM), freshly prepared nanoparticles were dense spherical structures which became fragmented after ultrasonication for 10 min at amplitude of 80. Untreated nanoparticle formulation turned turbid upon storage for 3 weeks at ambient conditions due to substantial swelling of the nanoparticles. Ultrasonicated nanoparticle formulation remained clear on storage. Although the particles had also swelled, they were no longer spherical, assuming instead an irregular shape with branching arms. In conclusion, high-intensity ultrasonication induced considerable damage on the chitosan nanoparticles which could affect their function as drug carriers.

Adjuvants, Pharmaceutic↗

PubMed2003

De novo synthesis of pyrimidine nucleotides; emerging interfaces with signal transduction pathways.

The de novo biosynthesis of pyrimidine nucleotides provides essential precursors for multiple growth-related events in higher eukaryotes. Assembled from ATP, bicarbonate and glutamine, the uracil and cytosine nucleotides are fuel for the synthesis of RNA, DNA, phospholipids, UDP sugars and glycogen. Over the past 2 decades considerable progress has been made in elucidating the mechanisms by which cellular pyrimidines are modulated to meet the needs of the cell. Recent studies demonstrate that CAD, a rate-limiting enzyme in the de novo synthesis of pyrimidines, is regulated through reversible phosphorylation, Myc-dependent transcriptional changes and caspase-mediated degradation. These studies point to increasing evidence for cooperation between key cell signaling pathways and basic elements of cellular metabolism, and suggest that these events have the potential to determine distinct cellular fates, including growth, differentiation and death. This review highlights some of the recent advances in the regulation of pyrimidine synthesis by growth-factor-stimulated signaling pathways.

Allosteric Regulation↗

PubMed2002

Observation of the decay K- --> pi(-)mu(+)mu(-) and measurements of the branching ratios for K+/- --> pi(+/-)mu(+)mu(-).

Using data collected with the HyperCP (E871) spectrometer during the 1997 fixed-target run at Fermilab, we report the first observation of the decay K--->pi(-)mu(+)mu(-) and new measurements of the branching ratios for K+/--->pi(+/-)mu(+)mu(-). By combining the branching ratios for the decays K+-->pi(+)mu(+)mu(-) and K--->pi(-)mu(+)mu(-), we measure Gamma(K+/--->pi(+/-)mu(+)mu(-))/Gamma(K+/--->all) = (9.8+/-1.0+/-0.5)x10(-8). The CP asymmetry between the rates of the two decay modes is [Gamma(K+-->pi(+)mu(+)mu(-))-Gamma(K--->pi(-)mu(+)mu(-))]/[Gamma(K+-->pi(+)mu(+)mu(-))+Gamma(K--->pi(-)mu(+)mu(-))] = -0.02+/-0.11+/-0.04.

Journal Article↗

PubMed2002

Interleukin-3 protects Bcr-Abl-transformed hematopoietic progenitor cells from apoptosis induced by Bcr-Abl tyrosine kinase inhibitors.

Bcr-Abl tyrosine kinase has been validated as a molecular target for the treatment of chronic myelogenous leukemia (CML). More recently, it has been reported that CML patients could develop resistance to the Bcr-Abl tyrosine kinase inhibitor, imatinib (STI571, Gleevec), pointing to the need for development of additional Bcr-Abl tyrosine kinase inhibitors or other therapeutic strategies. It was also found that a significant proportion of patients who received the Bcr-Abl inhibitor did not achieve complete cytogenetic response. Mechanisms for incomplete cytogenetic response to Bcr-Abl inhibition are not entirely clear. We report here three new pyrido[2,3-d]pyrimidine Bcr-Abl tyrosine kinase inhibitors, PD164199, PD173952, PD173958, that induced apoptosis of Bcr-Abl-dependent hematopoietic cells. An interleukin-3 (IL-3) autocrine loop was observed previously in primitive CD34(+)/Bcr-Abl(+) leukemic cells in CML patients. Using 32Dp210(Bcr-Abl)and Baf3p210(Bcr-Abl) cells as models, we tested whether IL-3 might protect Bcr-Abltransformed, IL-3-responsive cells from apoptosis caused by Bcr-Abl tyrosine kinase inhibition. Results of trypan blue exclusion, fluoroisothiocyanate-valyl-alanyl-aspartyl-[O-methyl] -fluoromethylketone (FITC-VAD-FMK), and Annexin-V/7-amino-actinomycin D (7-AAD) binding assays indicate that IL-3 could protect Bcr-Abl-transformed, IL-3 responsive hematopoietic progenitor cells from apoptosis induced by Bcr-Abl tyrosine kinase inhibitors. This finding raises the possibility that the IL-3 autocrine loop found in primitive CD34(+)/Bcr-Abl(+) cells in CML patients could contribute to the incomplete eradication of Bcr-Abl(+) cells by Bcr-Abl inhibition.

Annexin A5↗

PubMed2002

Intravesical sodium hyaluronate inhibits the rat urinary mast cell mediator increase triggered by acute immobilization stress.

PURPOSE: Mast cell activation and stress have been suggested as factors in the pathogenesis of interstitial cystitis, a painful disorder of the bladder that is diagnosed more frequently in women and characterized by increased urgency and frequency with absent infection. Intravesical sodium hyaluronate has been used to treat interstitial cystitis due to its possible replenishment of bladder glycosaminoglycans. We investigated the effect of sodium hyaluronate on the activation of bladder mast cell and release of proinflammatory mediators in the urine induced by acute immobilization stress in rats. MATERIALS AND METHODS: Using anesthesia a catheter was inserted in the bladder of 170 gm. female Sprague-Dawley rats. After emptying post-void residual urine a solution of normal saline, 0.08% or 0.4% sodium hyaluronate was introduced for 30 minutes. Each rat was allowed to recover from anesthesia and stressed for 30 minutes by confining it in a clear acrylic plastic immobilizer, while urine was continuously collected. Urinary histamine, rat mast cell protease-I and interleukin (IL)-6 were then determined. At the end of the experiments each rat was sacrificed by CO2 asphyxiation, and the bladder was removed and fixed with 4% paraformaldehyde. Frozen sections were stained with acidified toluidine blue, and the mast cell number and degree of activation were determined by granule extrusion and reduced cellular staining. RESULTS: Mean bladder mast cell activation plus or minus standard deviation in 6 control rats was 30.4% +/- 3.7% but it increased to 76.2% +/- 6.1% in 6 stressed animals (p = 0.0001). Intravesical administration of 0.4% sodium hyaluronate for 30 minutes in 6 rats before stress reduced mean bladder mast cell activation by 69.7% to 23.1% +/- 6.1% compared with stressed controls (p = 0.0003). However, compared to itself before stress there was no significant difference, indicating complete inhibition in 6 rats. Intravesical 0.08% sodium hyaluronate had a weaker inhibitory effect in 6 rats, decreasing mean degranulation by 22.5% to 59.1% +/- 7.6% (p = 0.02). In 6 rats stress increased the total mean amount of urinary rat mast cell protease-I by 271% from 0.14 +/- 0.09 to 0.52 +/- 0.17 ng. (p = 0.008). Pretreatment with 0.4% sodium hyaluronate reduced mean rat mast cell protease-I 80.8% compared with stressed controls (p = 0.008) and prevented any increase in response to stress in the same group of 8 rats with a mean pre-stress and post-stress level of 0.09 +/- 0.04 and 0.1 +/- 0.04 ng., respectively (p = 0.8). Acute stress increased mean urinary histamine in 6 rats 40.2% from 137.3 +/- 29.7 before to 193.7 +/- 7.6 ng./ml. after stress (p = 0.004). Pretreatment with 0.4% sodium hyaluronate reduced mean histamine 7.1% compared with stressed controls but completely prevented any increase in the same group of 8 rats, in which it was 174.5 +/- 23.1 before and remained 179.4 +/- 9.9 ng./ml. after stress (p = 0.75). Acute stress in 7 rats also increased the mean amount of IL-6 released in the urine by 31.5% from 775.9 +/- 69.2 to 1,021.1 +/- 93.3 pg./ml. (p = 0.007). Pretreatment with 0.4% sodium hyaluronate in 9 rats reduced mean IL-6 17% compared with stressed controls but again prevented any increase from baseline, since the value was 898.6 +/- 299.3 before and 824.4 +/- 196.4 pg./ml. after stress (p = 0.03). CONCLUSIONS: Immobilization stress induces bladder mast cell activation and the secretion of proinflammatory mediators, which are inhibited by sodium hyaluronate. Intravesical sodium hyaluronate may be a useful therapeutic option for interstitial cystitis, especially in patients with bladder mastocytosis who have symptom exacerbation with stress.

Administration, Intravesical↗

PubMed2001

Crystal structure of Sar1-GDP at 1.7 A resolution and the role of the NH2 terminus in ER export.

The Sar1 GTPase is an essential component of COPII vesicle coats involved in export of cargo from the ER. We report the 1.7-A structure of Sar1 and find that consistent with the sequence divergence of Sar1 from Arf family GTPases, Sar1 is structurally distinct. In particular, we show that the Sar1 NH2 terminus contains two regions: an NH2-terminal extension containing an evolutionary conserved hydrophobic motif that facilitates membrane recruitment and activation by the mammalian Sec12 guanine nucleotide exchange factor, and an alpha1' amphipathic helix that contributes to interaction with the Sec23/24 complex that is responsible for cargo selection during ER export. We propose that the hydrophobic Sar1 NH2-terminal activation/recruitment motif, in conjunction with the alpha1' helix, mediates the initial steps in COPII coat assembly for export from the ER.

Animals↗

PubMed2001

Inhibition of constitutively active Stat3 suppresses growth of human ovarian and breast cancer cells.

Signal transducers and activators of transcription (STATs) are transcription factors activated in response to cytokines and growth factors. Constitutively active Stat3 has been shown to mediate oncogenic transformation in cultured cells and induce tumor formation in mice. An increasing number of tumor-derived cell lines as well as samples from human cancer have been reported to express constitutively active Stat3 protein. We previously demonstrated that ovarian cancer cell lines express high levels of constitutively active Stat3. In this study, we show that inhibition of the Stat3 signaling pathway using the Janus Kinase-selective inhibitor, AG490, and a dominant negative Stat3 (Stat3beta) significantly suppresses the growth of ovarian and breast cancer cell lines harboring constitutively active Stat3. In the ovarian cancer cell lines, AG490 also diminished the phosphorylation of Stat3, Stat3 DNA binding activity, and the expression of Bcl-x(L). Further, AG490 induced significant apoptosis in ovarian and breast cancer cell lines expressing high levels of constitutively active Stat3 but had a less profound effect on normal cells lacking constitutively active Stat3. AG490 also enhanced apoptosis induced by cisplatin in ovarian cancer cells. These results suggest that inhibition of Stat3 signaling may provide a potential therapeutic approach for treating ovarian and breast cancers.

Apoptosis↗