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3501 citation(s) found for "Xu, Timothy".

Tracheobronchial Involvement in Wegener's Granulomatosis
Daum, Timothy E., Specks, U., Colby, Thomas V. , Edell, Eric S. , Brutinel, M., Prakash, Udaya B. S., DeRemee, Richard A., Specks, Ulrich

American journal of respiratory and critical care medicine | April 4, 2013 | Volume: 151 | Issue: 2 | Pages: 522-526

10.1164/ajrccm.151.2.7842215 | PMID 7842215 Get It

Abstract This study was designed to characterize the clinical spectrum and course of tracheobronchial involvement in Wegener's granulomatosis (WG). Of the 51 patients with biopsy-proven WG who underwent bronchoscopy at least once at our institution between January 1982 and November 1993, 30 (59%) had endobronchial abnormalities due to WG. Initial findings included subglottic stenosis in five (17%), ulcerating tracheobronchitis with or without inflammatory pseudotumors in 18 (60%), tracheal or bronchial stenosis without inflammation in four (13%), and hemorrhage without identifiable source in two (4%) patients. Nine patients with ulcerating tracheobronchitis on initial study had subsequent bronchoscopies for continued symptoms, which in seven cases documented the progression from ulcerating tracheobronchitis to stenosis without inflammation. Bronchoscopic interventions included dilation by rigid bronchoscope in three, YAG-laser treatment in one, and placement of silastic airway stents in three patients. Only the stents provided persistent airway patency. Endobronchial biopsies were performed on 21 occasions in 17 patients. Half of the specimens were helpful in establishing the diagnosis and in all but three in assessing disease activity. While antineutrophil cytoplasmic antibody titers reflect overall disease activity, no correlation with endobronchial inflammatory activity was apparent.
Pneumocystis carinii Induces the Release of Arachidonic Acid and its Metabolites from Alveolar Macrophages
Castro, M. P. De, Hoffman, O A, Standing, Joseph E., Rohrbach, Michael S., Morgenthaler, Timothy I. , Limper, Andrew H.

American Journal of Respiratory Cell and Molecular Biology | April 3, 2013 | Volume: 9 | Issue: 1 | Pages: 73-81

10.1165/ajrcmb/9.1.73 | PMID 8393326 Get It

Abstract Pneumocystis carinii is an opportunistic organism that causes severe lung injury in immunocompromised hosts. Macrophage responses to P. carinii are poorly defined. Arachidonic acid (AA) and its metabolites are potent mediators of inflammation and have been implicated in host response to microorganisms. We therefore examined the production of eicosanoids from rat and rabbit alveolar macrophages stimulated with purified P. carinii. [14C]AA-labeled rabbit macrophages released 8.50 ± 1.33% of the incorporated [14C]AA after 90 min in response to P. carinii (P = 0.0001 compared with unstimulated controls). In contrast, a similar number of rat alveolar macrophages exhibited a smaller but significant response to P. carinii, releasing 3.84 ± 1.54% of their [14C]AA after 90 min (P = 0.001 compared with control). We further determined that P. carinii stimulated substantial production of prostaglandin E2 and concurrently a small amount of leukotriene B4 release from alveolar macrophages. To further investigate whether serum opsonization of P. carinii enhances these alterations in AA metabolism, we assessed the effect of P. carinii immune serum on P. carinii-induced AA release. P. carinii opsonized with this antiserum caused significantly greater AA release from rat alveolar macrophages than either unopsonized P. carinii or organisms opsonized with nonimmune serum. Previous studies suggest that P. carinii interacts with macrophage β-glucan and mannose receptors. However, incubation of macrophages with P. carinii in the presence of either soluble β-glucan or α-mannan failed to alter the release of AA from macrophages in response to P. carinii. Macrophage release of eicosanoids represents a potentially important host inflammatory response to P. carinii infection.
Disease-Causing Mitochondrial Heteroplasmy Segregated Within Induced Pluripotent Stem Cell Clones Derived from a Patient with MELAS
Folmes, Clifford D.L. , Martinez‐Fernandez, Almudena , Li, Xing , McDonald, Amber , Oglesbee, Devin , Hrstka, Sybil , Pérez-Terzic, Carmen, Nelson, Timothy J. , Perales‐Clemente, Ester , Terzic, André , Nelson, Timothy J , Oglesbee, Devin , Folmes, Clifford D L , Hrstka, Sybil C

Stem Cells | April 3, 2013 | Volume: 31 | Issue: 7 | Pages: 1298-1308

10.1002/stem.1389 | PMID 23553816 Get It

Abstract Mitochondrial diseases display pathological phenotypes according to the mixture of mutant versus wild-type mitochondrial DNA (mtDNA), known as heteroplasmy. We herein examined the impact of nuclear reprogramming and clonal isolation of induced pluripotent stem cells (iPSC) on mitochondrial heteroplasmy. Patient-derived dermal fibroblasts with a prototypical mitochondrial deficiency diagnosed as mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) demonstrated mitochondrial dysfunction with reduced oxidative reserve due to heteroplasmy at position G13513A in the ND5 subunit of complex I. Bioengineered iPSC clones acquired pluripotency with multilineage differentiation capacity and demonstrated reduction in mitochondrial density and oxygen consumption distinguishing them from the somatic source. Consistent with the cellular mosaicism of the original patient-derived fibroblasts, the MELAS-iPSC clones contained a similar range of mtDNA heteroplasmy of the disease-causing mutation with identical profiles in the remaining mtDNA. High-heteroplasmy iPSC clones were used to demonstrate that extended stem cell passaging was sufficient to purge mutant mtDNA, resulting in isogenic iPSC subclones with various degrees of disease-causing genotypes. On comparative differentiation of iPSC clones, improved cardiogenic yield was associated with iPSC clones containing lower heteroplasmy compared with isogenic clones with high heteroplasmy. Thus, mtDNA heteroplasmic segregation within patient-derived stem cell lines enables direct comparison of genotype/phenotype relationships in progenitor cells and lineage-restricted progeny, and indicates that cell fate decisions are regulated as a function of mtDNA mutation load. The novel nuclear reprogramming-based model system introduces a disease-in-a-dish tool to examine the impact of mutant genotypes for MELAS patients in bioengineered tissues and a cellular probe for molecular features of individual mitochondrial diseases.
A Multicenter, Prospective Study of a New Fully Covered Expandable Metal Biliary Stent for the Palliative Treatment of Malignant Bile Duct Obstruction
Petersen, Bret T. , Kahaleh, Michel , Kozarek, Richard A. , Loren, David E. , Gupta, Kapil , Kowalski, Thomas E., Freeman, Martin L. , Chen, Yang K., Branch, M. Stanley, Edmundowicz, Steven A. , Glück, Michael , Binmoeller, Kenneth F., Baron, Todd H. , Kinney, Timothy P., Ross, William A., Jowell, Paul S., Carr‐Locke, David L. , Shah, Raj J. , Kahaleh, Michel , Edmundowicz, Steven A

Gastroenterology Research and Practice | March 27, 2013 | Volume: 2013 | Issue: No issue available | Pages: 1-7

10.1155/2013/642428 | PMID 23606835 Get It

Background and Study Aims. Endoscopic placement of self-expanding metal stents (SEMSs) is indicated for palliation of inoperable malignant biliary obstruction. A fully covered biliary SEMS (WallFlex Biliary RX Boston Scientific, Natick, USA) was assessed for palliation of extrahepatic malignant biliary obstruction.Patients and Methods. 58 patients were included in this prospective, multicenter series conducted under an FDA-approved IDE. Main outcome measurements included (1) absence of stent occlusion within six months or until death, whichever occurred first and (2) technical success, need for reintervention, bilirubin levels, stent patency, time to stent occlusion, and adverse events.Results. Technical success was achieved in 98% (57/58), with demonstrated acute removability in two patients. Adequate clinical palliation until completion of followup was achievedin 98% (54/55) ofevaluablepatients, with 1 reintervention due to stent obstruction after 142 days. Mean total bilirubin decreased from 8.9 mg/dL to 1.2 mg/dL at 1 month. Device-related adverse events were limited and included 2 cases of cholecystitis. One stent migrated following radiation therapy.Conclusions. The WallFlex Biliary fully covered stent yielded technically successful placement with uncomplicated acute removal where required, appropriate reduction in bilirubin levels, and low rates of stent migration and occlusion. This SEMS allows successful palliation of malignant extrahepatic biliary obstruction.
Novel treatment of a gastric Dieulafoy lesion with an over-the-scope clip
Gómez, Victoria , Lukens, Frank , Woodward, Timothy A., Baig, Kondal R. Kyanam Kabir

Endoscopy | March 25, 2013 | Volume: 45 | Issue: S 02 | Pages: E71-E71

10.1055/s-0032-1326073 | PMID 23526524 Get It

Long-term repair of T-cell synapse activity in a phase II trial of chemoimmunotherapy followed by lenalidomide consolidation in previously untreated chronic lymphocytic leukemia (CLL)
Ramsay, Alan G. , Leis, José F., Call, Timothy G. , LaPlant, Betsy, Bowen, Deborah A., Pettinger, Adam, Jelinek, Diane F., Hanson, Curtis A. , Shanafelt, Tait D. , Zent, Clive S. , Tun, Han W. , Kay, Neil E. , Ramsay, Alan G

Blood | March 15, 2013 | Volume: 121 | Issue: 20 | Pages: 4137-4141

10.1182/blood-2012-12-470005 | PMID 23493782 Get It

Key Points Lenalidomide consolidation repairs T-cell immune synapses in CLL patients. Lenalidomide consolidation improved the quality of response in CLL patients treated with chemoimmunotherapy.
Cigarette Smoking and Nonunion after Ankle Arthrodesis
Cobb, Tyson K., Gabrielsen, Timothy A., Campbell, Donald C., Wallrichs, Steven L., Ilstrup, Duane M.

Foot & Ankle International | March 3, 2013 | Volume: 15 | Issue: 2 | Pages: 64-68

10.1177/107110079401500202 | PMID 7981802 Get It

The relative risk of nonunion in smokers versus nonsmokers after ankle arthrodesis was determined in a case control study. Twenty-two patients were matched to 22 controls by age, sex, surgeon, surgical technique, and preoperative diagnosis. Information on duration, amount, and past history of smoking was obtained for these 44 patients. Ten of the patients were actively smoking at the time of surgery compared with four of the controls. Six of the patients had no history of smoking and six had stopped smoking before surgery. Eleven of the controls had no history of cigarette smoking and 7 had stopped smoking before surgery. The relative risk of nonunion was increased 3.75 times for active smokers. When patients did not have any known risk factors for nonunion, the risk of nonunion for smokers was 16 times the risk of nonunion for nonsmokers
Treatment of Hallux Valgus in Adolescents by the Chevron Osteotomy
Zimmer, Timothy J., Johnson, Kenneth A. , Klassen, Rudolph A.

Foot & Ankle | March 3, 2013 | Volume: 9 | Issue: 4 | Pages: 190-193

10.1177/107110078900900408 | PMID 2731828 Get It

Between 1978 and 1984, 20 adolescent patients underwent 35 chevron osteotomies of the first metatarsal for correction of painful hallux valgus. After an average follow-up of 64 months, 85% of the patients expressed overall satisfaction. The cosmetic effect was the most satisfactory result (90%), followed by relief of pain (85%) and lack of limitations in footwear (65%). Radiographic evaluation did not seem to correlate with the final clinical result. The chevron osteotomy is a reasonable operative procedure for correction of hallux valgus in adolescents.
Neurilemoma of the Lower Extremity
Spiegl, Paul V., Cullivan, W. Timothy, Reiman, Herbert M., Johnson, Kenneth A.

Foot & Ankle | March 3, 2013 | Volume: 6 | Issue: 4 | Pages: 194-198

10.1177/107110078600600404 | PMID 3957182 Get It

A series of 76 patients with 85 neurilemomas of the lower extremity was reviewed. The tumors were located throughout the lower extremity and had varied clinical presentations, which often posed problems in diagnosis. Pain, however, was a consistent symptom, and 63 (83%) of the patients presented with local or radiating (or both) pain. Electromyography was done in seven cases, but the results were abnormal in only two. When evaluating a painful mass or an atypical pain in the lower extremity, the clinician should have a high index of suspicion for neurilemoma.