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Mayo Clinic

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12581 citation(s) found for "Ma, John".

Adjuvant Radiotherapy and Chemotherapy for Pancreatic Carcinoma: The Mayo Clinic Experience (1975-2005)
Corsini, Michele M., Miller, Robert C. , Haddock, Michael G. , Donohue, John H., Farnell, Michael B., Nagorney, David M. , Jatoi, Aminah , Kim, George P., Bhatia, S., Iott, Matthew J., Gunderson, Leonard L., McWilliams, Robert R.

Journal of Clinical Oncology | July 17, 2008 | Volume: 26 | Issue: 21 | Pages: 3511-3516

10.1200/jco.2007.15.8782 | PMID 18640932 Get It

Purpose To determine prognostic factors and impact of adjuvant chemotherapy (CT) and radiotherapy (RT) on overall survival (OS) after resection of pancreatic adenocarcinoma. Patients and Methods We performed a retrospective review 472 consecutive patients who underwent complete resection with negative margins (R0) for invasive carcinoma (T1-3N0-1M0) of the pancreas between 1975 and 2005 at the Mayo Clinic in Rochester, MN. Exclusion criteria included metastatic or unresectable disease at surgery, positive surgical margins, and indolent tumor types (islet cell tumors and mucinous cystadenocarcinoma). Median RT dose was 50.4 Gy in 28 fractions; 98% of RT patients also received concurrent fluorouracil-based CT. Results Six patients died within 30 days of surgery. For the 466 surviving patients, median follow-up was 32.4 months; median OS was 21.6 months. Median OS after adjuvant CT-RT was 25.2 versus 19.2 months after no adjuvant therapy (P = .001). Two-year OS was 50% versus 39%, and 5-year OS was 28% versus 17%. Adverse prognostic factors identified by univariate and multivariate analysis included positive lymph nodes (risk ratio [RR] = 1.3; P < .001), high histologic grade (RR = 1.2; P < .001), and no adjuvant therapy (RR = 1.3; P < .001). Tumor extension beyond the pancreas was an adverse prognostic factor by univariate analysis alone (P = .03). Patients receiving adjuvant therapy had more adverse prognostic factors than those not receiving adjuvant therapy (P = .001). Conclusion This study represents one of the largest, single-institution, retrospective reviews of adjuvant therapy in patients after R0 resection of carcinoma of the pancreas. Overall survival was better in patients who received adjuvant CT-RT.
Comparison between Immunoturbidimetry, Size-Exclusion Chromatography, and LC-MS to Quantify Urinary Albumin
Shaikh, Aisha , Seegmiller, Jesse C. , Borland, Timothy M., Burns, Bradley E., Ladwig, Paula M. , Kumar, Rajiv , Larson, Timothy S., Singh, Ravinder J. , Lieske, John C. , Kumar, Rajiv

Clinical Chemistry | July 11, 2008 | Volume: 54 | Issue: 9 | Pages: 1504-1510

10.1373/clinchem.2008.107508 | PMID 18617580 Get It

Abstract Background: The accurate and precise measurement of urinary albumin is critical, since even minor increases are diagnostically sensitive indicators of renal disease, cardiovascular events, and risk for death. To gain insights into potential measurement biases, we systematically compared urine albumin measurements performed by LC-MS, a clinically available immunoturbidimetric assay, and size-exclusion HPLC. Methods: We obtained unused clinical urine samples from 150 patients who were stratified by degrees of albuminuria (&lt;20 mg/L, 20–250 mg/L, &gt;250 mg/L) as determined by the immunoturbidimetric assay used in our clinical laboratory (Roche Hitachi 912). Urine albumin was then remeasured via LC-MS and HPLC (Accumin™) assays. Results: The immunoturbidimetric assay, calibrated using manufacturer-supplied serum-derived calibrators (Diasorin), underestimated albumin compared with LC-MS. After calibration with purified HSA, this immunoturbidimetric assay correlated well with LC-MS. HPLC overestimated albumin compared with both LC-MS and immunoturbidimetry. The current LC-MS and HPLC assays both performed poorly at concentrations &lt;20 mg/L. Conclusions: Efforts are needed to establish gold-standard traceable calibrators for clinical assays. LC-MS is a specific method to quantify albumin in native urine when concentrations exceed 20 mg/L, and therefore could be employed for standardization among assays.
Estrogen Supplementation Selectively Enhances Hypothalamo-Pituitary Sensitivity to Ghrelin in Postmenopausal Women
Kok, Petra, Paulo, Remberto, Cosma, Mihaela, Mielke, Kristi L., Miles, John M., Bowers, Cyril Y., Veldhuis, Johannes D. , Miles, John M.

The Journal of Clinical Endocrinology & Metabolism | July 9, 2008 | Volume: 93 | Issue: 10 | Pages: 4020-4026

10.1210/jc.2008-0522 | PMID 18611978 Get It

Context: Sex-steroid hormones amplify pulsatile GH secretion by unknown mechanisms. Ghrelin is the most potent natural GH secretagogue discovered to date. A plausible unifying postulate is that estradiol (E2) enhances hypothalamo-pituitary sensitivity to ghrelin (a physiological effect). The hypothesis is relevant to understanding the basis of hyposomatotropism in aging and other relatively hypogonadal states. Objective: Our objective was to test the hypothesis that E2 supplementation potentiates ghrelin’s stimulation of pulsatile GH secretion. Setting: The study was conducted at an academic medical center. Subjects: Healthy postmenopausal women (n = 20) were included in the study. Interventions: Separate-day iv infusions of saline vs. five graded doses of ghrelin were performed in volunteers prospectively randomly assigned to receive (n = 8) or not receive (n = 12) transdermal E2 for 21 d were performed. Measures: GH secretion was estimated by deconvolution analysis and abdominal visceral fat mass determined by computerized axial tomography were calculated. Results: E2 supplementation augmented ghrelin’s stimulation of basal (nonpulsatile) GH secretion by 3.6-fold (P = 0.022), increased GH responses to low-dose ghrelin by 2.9-fold (P = 0.035), did not alter ghrelin efficacy, and elicited more regular patterns of acylated ghrelin concentrations during saline infusion (P = 0.033). Abdominal visceral fat negatively determined responses to ghrelin (R = −0.346; P &lt; 0.005). Conclusions: Transdermal E2 supplementation potentiates GH secretion stimulated by physiological but not pharmacological concentrations of acylated ghrelin, and concomitantly regularizes patterns of bioactive ghrelin secretion in postmenopausal women. Accordingly, the estrogen milieu appears to control sensitivity of the hypothalamopituitary unit to acylated ghrelin.
Thyroid-stimulating hormone pituitary adenomas
Erickson, Dana , Castro, M. Regina , Atkinson, John L. D., Clarke, Michelle J.

Journal of Neurosurgery | June 30, 2008 | Volume: 109 | Issue: 1 | Pages: 17-22

10.3171/jns/2008/109/7/0017 | PMID 18590428 Get It

Object Thyroid-stimulating hormone (TSH)–secreting pituitary adenomas are rare, representing < 2% of all pituitary adenomas. Methods The authors conducted a retrospective analysis of patients with TSH-secreting or clinically silent TSH-immunostaining pituitary tumors among all pituitary adenomas followed at their institution between 1987 and 2003. Patient records, including clinical, imaging, and pathological and surgical characteristics were reviewed. Twenty-one patients (6 women and 15 men; mean age 46 years, range 26–73 years) were identified. Of these, 10 patients had a history of clinical hyperthyroidism, of whom 7 had undergone ablative thyroid procedures (thyroid surgery/131I ablation) prior to the diagnosis of pituitary adenoma. Ten patients had elevated TSH preoperatively. Seven patients presented with headache, and 8 presented with visual field defects. All patients underwent imaging, of which 19 were available for imaging review. Sixteen patients had macroadenomas. Results Of the 21 patients, 18 underwent transsphenoidal surgery at the authors' institution, 2 patients underwent transsphenoidal surgery at another facility, and 1 was treated medically. Patients with TSH-secreting tumors were defined as in remission after surgery if they had no residual adenoma on imaging and had biochemical evidence of hypo-or euthyroidism. Patients with TSH-immunostaining tumors were considered in remission if they had no residual tumor. Of these 18 patients, 9 (50%) were in remission following surgery. Seven patients had residual tumor; 2 of these patients underwent further transsphenoidal resection, 1 underwent a craniotomy, and 4 underwent postoperative radiation therapy (2 conventional radiation therapy, 1 Gamma Knife surgery, and 1 had both types of radiation treatment). Two patients had persistently elevated TSH levels despite the lack of evidence of residual tumor. On pathological analysis and immunostaining of the surgical specimen, 17 patients had samples that stained positively for TSH, 8 for α-subunit, 10 for growth hormone, 7 for prolactin, 2 for adrenocorticotrophic hormone, and 1 for follicle-stimulating hormone/luteinizing hormone. Eleven patients (61%) ultimately required thyroid hormone replacement therapy, and 5 (24%) required additional pituitary hormone replacement. Of these, 2 patients required treatment for new anterior pituitary dysfunction as a complication of surgery, and 2 patients with preoperative partial anterior pituitary dysfunction developed complete panhypopituitarism. One patient had transient diabetes insipidus. The remainder had no change in pituitary function from their preoperative state. Conclusions Thyroid-stimulating hormone–secreting pituitary lesions are often delayed in diagnosis, are frequently macroadenomas and plurihormonal in terms of their pathological characteristics, have a heterogeneous clinical picture, and are difficult to treat. An experienced team approach will optimize results in the management of these uncommon lesions.
Head and Neck MRA at 3.0T
Bernstein, Matt A. , Huston, John

Current Protocols in Magnetic Resonance Imaging | June 30, 2008 | Volume: 15 | Issue: 1 | Pages: No page available

10.1002/0471142719.mia0708s15 Get It

Abstract3.0T MRI scanners are becoming more widely used in clinical practice, particularly for neurological applications. The increased signal‐to‐noise ratio (SNR) provided by 3.0T compared to 1.5T is particularly useful for applications like magnetic resonance angiography (MRA). A protocol to image the intracranial circulation with 3‐D time of flight (3DTOF), and a protocol to image the carotid, vertebral, and basilar arteries with contrast‐enhanced MRA are presented. The increased SNR at 3.0T is used to increase the spatial resolution. For the 3DTOF exam, the acquisition time is also reduced with the use of parallel imaging.
Can Physicians Accurately Predict Survival Time in Patients with Metastatic Cancer? Analysis of RTOG 97-14
Hartsell, William F. , DeSilvio, Michelle, Bruner, Deborah Watkins , Scarantino, Charles W., Ivker, Robert, Roach, Mack , Demas, William F., Movsas, Benjamin , Petersen, Ivy A. , Konski, André , Suh, John H. , Bruner, Deborah

Journal of Palliative Medicine | June 27, 2008 | Volume: 11 | Issue: 5 | Pages: 723-728

10.1089/jpm.2007.0259 | PMID 18588404 Get It

A Comparison of Arm-and-Thigh Blood Pressures in Patients With Abdominal Aortic Aneurysms
Spittel, John A., Hines, Edgar A.

Angiology | June 26, 2008 | Volume: 11 | Issue: 1 | Pages: 1-4

10.1177/000331976001100101 | PMID 13833397 Get It

A Statistical Model for iTRAQ Data Analysis
Hill, Elizabeth G. , Schwacke, John H., Comte‐Walters, Susana , Slate, Elizabeth H. , Oberg, Ann L. , Eckel‐Passow, Jeanette E. , Therneau, Terry M. , Schey, Kevin L.

Journal of Proteome Research | June 26, 2008 | Volume: 7 | Issue: 8 | Pages: 3091-3101

10.1021/pr070520u | PMID 18578521 Get It

Relative value of ZAP-70, CD38, and immunoglobulin mutation status in predicting aggressive disease in chronic lymphocytic leukemia
Rassenti, Laura Z., Jain, Sonia , Keating, Michael J. , Wierda, William G. , Grever, Michael R. , Byrd, John C. , Brown, Jennifer R. , Greaves, Andrew, Rai, Kanti R., Byrd, John C. , Kay, Neil E. , Gribben, John G. , Neuberg, Donna , He, Feng , Rai, Kanti R., Kipps, Thomas J. , Byrd, John C

Blood | June 25, 2008 | Volume: 112 | Issue: 5 | Pages: 1923-1930

10.1182/blood-2007-05-092882 | PMID 18577710 Get It

AbstractLeukemia-cell expression of ZAP-70, CD38, or unmutated immunoglobulin heavy chain variable region genes (U-IGHV) each is associated with aggressive disease in patients with chronic lymphocytic leukemia (CLL). To assess the relative strength of each marker, we defined thresholds for designating a case as positive for CD38 or ZAP-70 in a test cohort of 307 patients and used these data-defined criteria to stratify patients in an independent cohort of 705 patients. Multivariable analysis revealed that ZAP-70 was the strongest risk factor. Knowledge of the IGHV mutation status or CD38 did not improve our ability to predict the time to first treatment except for ZAP-70–negative cases, which could be segregated into 2 groups of intermediate-risk or low-risk disease based on whether they expressed unmutated or mutated IGHV. ZAP-70 maintained its high relative prognostic value for the subset of patients with early-stage, asymptomatic disease, including patients evaluated within 1 year of diagnosis. Although it is premature to recommend therapy based on these risk factors, patients with ZAP-70–positive CLL cells should be monitored closely for disease progression as they have a median time from diagnosis to requiring initial therapy by standard criteria of approximately 3 years.
In Reply
Leibovich, Bradley C. , Sheinin, Yuri, Lohse, Christine M. , Thompson, R. Houston, Cheville, John C. , Závada, J, Kwon, Eugene D.

Journal of Clinical Oncology | June 18, 2008 | Volume: 26 | Issue: 18 | Pages: 3107-3109

10.1200/jco.2008.16.2164 Get It