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Mandeep Singh

Publications and source records attributed to Mandeep Singh.

At least 19 recordsLinked to original sources
PubMed2026

Identification of Novel Sources and Genetic Mapping for Bacterial Leaf Streak Resistance in a Geographically Diverse Panel of Wheat.

Bacterial leaf streak (BLS), caused by Xanthomonas translucens pv. undulosa (Xtu), has recently emerged as a significant threat to wheat production in the Northern Great Plains region of the United States. Deploying resistant cultivars is an economical and practical method of controlling BLS. To identify novel sources of BLS resistance, we screened a set of 355 bread wheat landraces and cultivars representing global diversity for their response to BLS. A wide distribution of seedling responses against BLS was observed, with most genotypes displaying a moderately to highly susceptible response. Notably, we identified 5 resistant and 33 moderately resistant responses. A high-resolution genome-wide association study using 302,524 high-quality single-nucleotide polymorphisms (SNPs) identified 10 significant marker-trait associations (MTAs) on chromosomes 1A, 1D, 3B, 4A, and 5A corresponding to unique genomic regions associated with BLS resistance. Compared with previous studies, four of these genomic regions are likely novel. Of these, MTA 'scaffold15531_2782724' associated with q5A.1 was highly significant (-log10P = 9.39) and exhibited the highest SNP effect (0.35). An association on chromosome 3B validated a previously identified 3B quantitative trait locus (QTL) mapped at approximately 6 Mbp in the hard red spring wheat cultivar 'Boost', and the high-resolution mapping from our study further refined the interval for this QTL. Furthermore, the narrow haplotype blocks reported in this study could be valuable for fine mapping of important regions. The novel resistant sources, along with identified genomic loci and corresponding SNP markers from this study, would be helpful for wheat-breeding programs to enhance BLS resistance.[Formula: see text] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

BLS↗
PubMed2006

Imaging of trabeculectomy blebs using anterior segment optical coherence tomography.

OBJECTIVE: To image trabeculectomy blebs using anterior segment optical coherence tomography (AS-OCT). DESIGN: Prospective cross-sectional study. PARTICIPANTS: Fifty-five patients who had previously undergone trabeculectomy surgery. METHODS: All blebs were imaged with a prototype of the AS-OCT. Standardized color monophotographs of blebs were also obtained. Blebs were assessed for the following qualitative features: bleb height, thickness of the conjunctiva in the bleb wall, presence of cystic spaces within the bleb wall, apposition of the scleral flap to underlying sclera, and patency of the internal ostium. MAIN OUTCOME MEASURES: For blebs with preoperative intraocular pressure (IOP) > 18 mmHg with or without ocular hypotensive medication, success was defined as last recorded IOP< or =18 mmHg without topical glaucoma medication. For blebs with preoperative IOP< or =18 mmHg with ocular hypotensive medication, success was defined last recorded IOP< or =18 mmHg with cessation of ocular hypotensive medication. For blebs with preoperative IOP< or =18 mmHg without ocular hypotensive medication, a 20% drop in IOP with no ocular hypotensive medication was accepted as success. RESULTS: Seventy-eight blebs in eyes of 55 patients were imaged. There were 32 (58.2%) men and the mean age was 68.9+/-11.5 years. Fifty-seven (73.1%) blebs were classified as successful. Anterior segment optical coherence tomography identified the following bleb characteristics: total bleb height, bleb cavity, bleb wall thickness, tangential and radial dimensions, scleral flap thickness, and patency of the internal ostium. The majority of successful blebs displayed thickening of the bleb wall. Failed blebs were mostly low and were characterized by ostial occlusion, apposition of conjunctiva-episclera to sclera or apposition of the scleral flap to its bed. Thickening of the bleb wall was typically absent. CONCLUSIONS: AS-OCT is a promising tool to image trabeculectomy blebs. It was able to demonstrate features of bleb morphology not visible with the slit lamp.

Aged↗
PubMed2006

Isolated elevation in troponin T after percutaneous coronary intervention is associated with higher long-term mortality.

OBJECTIVES: The aim of this study was to evaluate whether, in patients with normal post-procedure CK-MB, an isolated elevation in cardiac troponin T (cTnT) predicts long-term survival. BACKGROUND: Cardiac troponin T is a sensitive and specific marker of myonecrosis. There is little known about the incidence and prognostic significance of an isolated elevation of cTnT without a rise in creatine kinase (CK)-MB following PCI. METHODS: We evaluated the outcomes of 1,949 patients from the Mayo Clinic registry who had normal pre-procedure cTnT and CK-MB, required nonemergency percutaneous coronary intervention (PCI), and had normal CK-MB after the procedure. RESULTS: An elevation in cTnT (cTnT+) was observed in 383 patients (19.6%) (median 0.04 ng/ml, interquartile range 0.03 to 0.06 ng/ml). The TnT+ status was associated with adverse clinical and angiographic characteristics, and multivessel PCI. Over the median follow-up duration of 26 months, mortality (p < 0.001) and the combined rate of death and myocardial infarction (p = 0.004) were significantly higher in cTnT+ patients. Estimated 3-year survival for those with and without cTnT elevation was 86.9% and 93.2%, respectively. By multivariate analysis, an elevation in cTnT after PCI was an independent predictor of increased long-term mortality. A doubling in the post-PCI cTnT was associated with a partial hazard ratio of 1.20 (95% confidence interval 1.02 to 1.40; p = 0.023). CONCLUSIONS: An isolated minor elevation in cTnT after PCI provides long-term prognostic information regarding mortality and myocardial infarction.

Aged↗
PubMed2006

Relation of preprocedural statin therapy to in-hospital procedural complications following percutaneous coronary interventions in patients with hyperlipidemia.

We investigated whether the observed protective effect of hyperlipidemia is stronger in patients who take statins and, if so, whether that effect is likely due to patient characteristics associated with statin use. In-hospital complications and long-term outcomes of patients with hyperlipidemia (cholesterol level > or = 240 mg/dl) undergoing percutaneous coronary interventions (PCI) on statins (group Ia, n = 2,052) and not on statins (group Ib, n = 1,650) were compared with 726 patients with lower cholesterol levels (group II). Despite a higher prevalence of co-morbidities and worse angiographic characteristics in patients with hyperlipidemia, patients in group Ia had significantly lower in-hospital mortality (0% vs 2% in the other 2 groups, p < 0.001), a lower increase in the postprocedure creatine kinase-MB fraction (14% vs 27% in group Ib and 28% in group II, p < 0.001), and fewer PCI complications (15% vs 30% in groups Ib and II, p < 0.001). After adjustment, patients in group Ia had a significant decrease in complications (odds ratio 0.72, 95% confidence interval 0.65 to 0.92, p = 0.009). In contrast, those in group Ib had outcomes similar to those of patients with lower cholesterol. After application of propensity analysis to adjust for the likelihood of receiving statins based on clinical, angiographic, and procedural characteristics, group Ia had fewer in-hospital complications (odds ratio 0.75, 95% confidence interval 0.62 to 0.90, p = 0.002) and lower in-hospital mortality (odds ratio 0.32, 95% confidence interval 0.12 to 0.84, p = 0.021). After successful PCI, overall survival after dismissal and survival free of myocardial infarction and target vessel revascularization were similar. In conclusion, hyperlipidemia per se is not associated with lower in-hospital complications after PCI. The benefit is largely limited to patients on statin treatment.

Aged↗
PubMed2006

A total of 1,007 percutaneous coronary interventions without onsite cardiac surgery: acute and long-term outcomes.

OBJECTIVES: We sought to compare clinical outcomes of elective percutaneous coronary intervention (PCI) and primary PCI for ST-segment elevation myocardial infarction (STEMI) at a community hospital without onsite cardiac surgery to those at a tertiary center with onsite cardiac surgery. BACKGROUND: Disagreement exists about whether hospitals with cardiac catheterization laboratories, but without onsite cardiac surgery, should develop PCI programs. Primary PCI for STEMI at hospitals without onsite cardiac surgery have achieved satisfactory outcomes; however, elective PCI outcomes are not well defined. METHODS: A total of 1,007 elective PCI and primary PCI procedures performed from March 1999 to August 2005 at the Immanuel St. Joseph's Hospital-Mayo Health System (ISJ) in Mankato, Minnesota, were matched one-to-one with those performed at St. Mary's Hospital (SMH) in Rochester, Minnesota. Strict protocols were followed for case selection and PCI program requirements. Clinical outcomes (in-hospital procedural success, death, any myocardial infarction, Q-wave myocardial infarction, and emergency coronary artery bypass surgery) and follow-up survival were compared between groups. RESULTS: Among 722 elective PCIs, procedural success was 97% at ISJ compared with 95% at SMH (p = 0.046). Among 285 primary PCIs for STEMI, procedural success was 93% at ISJ and 96% at SMH (p = 0.085). No patients at ISJ undergoing PCI required emergent transfer for cardiac surgery. Survival at two years' follow-up by treatment location was similar for patients with elective PCI and primary PCI. CONCLUSIONS: Similar clinical outcomes for elective PCI and primary PCI were achieved at a community hospital without onsite cardiac surgery compared with those at a tertiary center with onsite cardiac surgery using a prospective, rigorous protocol for case selection and PCI program requirements.

Aged↗
PubMed2006

Geographical differences in the rates of angiographic restenosis and ischemia-driven target vessel revascularization after percutaneous coronary interventions: results from the Prevention of Restenosis With Tranilast and its Outcomes (PRESTO) Trial.

UNLABELLED: Many cardiologists consider it reasonable to assume in clinical practice that percutaneous coronary intervention using drug-eluting stents ought to be considered equivalent, if not superior, to bypass surgery. In the absence of a definitive clinical trial to support this view, how should the prudent, cutting-edge cardiologist proceed? OBJECTIVES: This study assessed the geographical differences in target vessel revascularization (TVR) after percutaneous coronary intervention (PCI) in the Prevention of Restenosis With Tranilast and its Outcomes (PRESTO) trial. BACKGROUND: An aggressive approach to PCI is more common in the U.S. than in other countries. The impact of this approach on restenosis outcomes has not been studied. METHODS: Using the PRESTO trial, we compared nine-month ischemic TVR after PCI in U.S.-treated patients (n = 5,026) with rates in other countries (n = 6,458). We defined TVR as repeat intervention for chest pain/positive stress test. Additionally, angiographic restenosis (> or =50% narrowing or > or =50% loss of gain at nine-month follow-up) was compared between U.S. and non-U.S. patients within the prespecified angiographic subset (n = 2,823). Regression models were developed to adjust for clinical and lesion-related characteristics. RESULTS: Higher rates of TVR (18% vs. 11%), and angiographic restenosis (65% vs. 48%) were observed in patients treated in the U.S. as compared with the other patients (p < 0.01 for both comparisons). Patients treated in the U.S. were more likely to be female, diabetic, not currently smoking, to have unstable angina, and to have a prior PCI. In U.S. patients, lesions tended to be longer, but less likely to be American College of Cardiology/American Heart Association class C. After adjusting for clinical and angiographic variables, PCI in the U.S. was still associated with increased angiographic restenosis and ischemic TVR. CONCLUSIONS: Angiographic restenosis and ischemia-driven TVR rates were higher in patients treated in the U.S. The difference could only partially be explained by the higher prevalence of measured adverse clinical and angiographic features.

Angioplasty, Balloon, Coronary↗
PubMed2006

Myocardial perfusion in apical ballooning syndrome correlate of myocardial injury.

BACKGROUND: The pathophysiology of the apical ballooning syndrome (ABS) is poorly understood. This study evaluated myocardial perfusion abnormalities at the time of presentation in patients with ABS and examined whether abnormal microvascular blood flow predicts the extent of myocardial injury. METHODS: We evaluated 42 consecutive patients, all women, with a diagnosis of ABS and technically adequate angiograms for the assessment of the TIMI myocardial perfusion grade (TMPG), an index of myocardial perfusion. RESULTS: Abnormal myocardial perfusion was present in 29 (69%) patients. There were no differences in age, frequency of conventional coronary atherosclerosis risk factors, left ventricular ejection fraction at either presentation or follow-up, congestive heart failure at presentation, or length of hospital stay between patients with normal versus those with abnormal TMPG. Patients with abnormal TMPG had higher peak troponin level compared with patients with normal TMPG (0.84 +/- 0.68 vs 0.42 +/- 0.33 ng/mL, P = .047). Similarly, ST elevation or deep T-wave inversion on the electrocardiogram was more common in patients with abnormal perfusion (86% vs 46%, P = .006). CONCLUSION: Impaired myocardial perfusion due to abnormal microvascular blood flow is frequently present in patients with ABS and correlates with the extent of myocardial injury. Microvascular dysfunction likely play a pivotal role in the pathogenesis of myocardial stunning in ABS.

Adult↗
PubMed2006

Elective percutaneous coronary intervention without on-site cardiac surgery: clinical and economic implications.

BACKGROUND: Low procedural complication rates, barriers to access, and patient preference have encouraged the development of percutaneous coronary intervention (PCI) programs at centers that are often closer to home but without on-site cardiac surgical capability. OBJECTIVES: We compared clinical and economic outcomes associated with performing low-risk elective PCI at a community hospital without on-site cardiac surgery with those obtained at a more remote tertiary care center with on-site cardiac surgery. DESIGN AND MEASURES: We matched 257 patients undergoing low-risk, elective PCI at a community hospital (Immanuel St. Joseph's Hospital [ISJ] between January 27, 2000, and July 31, 2002) to 514 PCI patients treated at a tertiary care hospital (Saint Marys Hospital [SMH] between January 27, 2000, and April 30, 2002) based on clinical and lesion criteria. Clinical outcomes (in-hospital procedural success and target vessel failure during long-term follow up) and economic outcomes (direct medical costs, billed charges, and hospital length of stay [LOS]) were compared between groups. The Mayo Clinic PCI Registry (containing clinical, angiographic, and follow-up data) and administrative data were used in matching and outcomes assessment. RESULTS: Procedural success was achieved more often among ISJ-treated patients (99% vs. 95%; P = 0.02); however, no difference in target vessel failure rates was observed during a median follow-up time of 3.1 years (estimated 1-year event rate: 15.2% vs. 14.8%; P = 0.46). ISJ-treated patients incurred, on average, $3024 more in estimated total costs ($13,771 vs. $10,746; P < 0.001) and $6084 more in billed charges (P < 0.001), but incurred similar LOS post procedure (1.53 days). CONCLUSIONS: Similar clinical outcomes were achieved at a community hospital without on-site cardiac surgery but at significantly increased direct medical cost. Patients, providers, hospitals, payers, and policymakers should consider whether the benefits associated with locally provided specialized cardiovascular services warrant this additional cost.

Cardiac Care Facilities↗
PubMed2005

Emergency coronary artery bypass surgery for percutaneous coronary interventions: changes in the incidence, clinical characteristics, and indications from 1979 to 2003.

OBJECTIVES: The purpose of the current study was to evaluate the changes in incidence, clinical characteristics, and indications for emergency coronary artery bypass grafting (CABG) in patients undergoing percutaneous coronary intervention (PCI) from 1979 to 2003. BACKGROUND: Emergency CABG after PCI is associated with significant morbidity and mortality. METHODS: Data from 23,087 patients who underwent PCI at Mayo Clinic from 1979 to 2003 were analyzed. Patients were divided into three groups: the "pre-stent" era, 1979 to 1994 (n = 8,905); the "initial stent era," 1995 to 1999 (n = 7,605); and the "current stent era," 2000 to 2003 (n = 6,577). RESULTS: Although patients undergoing PCI in the recent time periods had more high-risk features, there was a significant decrease in the incidence of emergency CABG from 2.9% to 0.7% to 0.3% across the groups (p < 0.001). Patients requiring emergency surgery in the recent time periods had a higher prevalence of hypertension, prior revascularization, and left ventricular dysfunction (ejection fraction <40%), as well as more complex coronary lesions. Fewer patients in the current stent era had coronary artery dissections and abrupt vessel closure requiring emergency CABG. The in-hospital mortality rate for emergency CABG patients remains unchanged and ranges from 10% to 14%. CONCLUSIONS: The current study demonstrates that despite the increase in high-risk patients undergoing PCI, there has been a marked decrease in the incidence of patients requiring emergency CABG. However, the in-hospital mortality rate for those requiring emergency CABG remains high and unchanged.

Aged↗
PubMed2005

Prediction of complications following nonemergency percutaneous coronary interventions.

Previous models for prediction of complications after percutaneous coronary interventions (PCIs) have included in-hospital mortality and major in-hospital complications. In general, these models have excluded elevated cardiac biomarkers as a complication. We sought to determine whether a risk model could predict complications, including biomarker elevation, in patients undergoing nonemergency PCI. We examined the outcomes of nonemergency PCI performed on patients at Mayo Clinic from 2000 to 2003. The primary end point was in-hospital complications of death, myocardial infarction (MI) (Q-wave MI, or post-PCI creatine kinase-MB elevation >or=3 times the upper limit of normal), emergency coronary artery bypass grafting, or stroke. We used the Hosmer-Lemeshow test to demonstrate the adequacy of the model fit, and the c-index for discriminatory ability of the model. Of 2,894 nonemergency PCIs, the end point was noted in 232 (8%). The final prediction model included vein graft intervention (odds ratio [OR] 2.19), angiographic thrombus (OR 2.12), preprocedure stenosis of a minor (OR 1.98) or major (OR 1.62) side branch, and type C lesion (OR 1.48). The model had modest ability to discriminate between event and nonevent patients (c = 0.641). In the 500 bootstrap samples for internal validation, the c-index was 0.642 +/- 0.020, indicating only fair discriminatory ability. The average number of observed events was 232.0 +/- 14.7 compared with 232.1 +/- 2.5 expected events (average difference -0.06 +/- 14.5). In conclusion, the 5 risk variables associated with an increased risk of complications in patients undergoing elective PCI included vein graft intervention, presence of angiographic thrombus, stenosis of a major or minor side branch, and type C lesion; however, the discriminatory ability of the model derived from the variables was only modest.

Aged↗
PubMed2005

Prediction of mortality after primary percutaneous coronary intervention for acute myocardial infarction: the CADILLAC risk score.

OBJECTIVES: We sought to develop a simple risk score for predicting mortality after primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). BACKGROUND: Accurate risk stratification after primary PCI is important. Previous risk scores after reperfusion therapy have incorporated clinical +/- angiographic variables but have not considered baseline left ventricular function. Moreover, prior studies have not been validated against independent databases or studies. METHODS: The databases from the two largest multicenter, randomized AMI trials of primary PCI were utilized for score derivation (the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications [CADILLAC] trial, n = 2,082) and subsequent validation (the Stent-Primary Angioplasty in Myocardial Infarction [Stent-PAMI] trial, n = 900). Logistic regression and the jackknife procedure were used to select correlates of one-year mortality that were subsequently weighted and integrated into an integer scoring system. RESULTS: Seven variables selected from the initial multivariate model were weighted proportionally to their respective odds ratio for one-year mortality (age >65 years [2 points], Killip class 2/3 [3 points], baseline left ventricular ejection fraction <40% [4 points], anemia [2 points], renal insufficiency [3 points], triple-vessel disease [2 points], and post-procedural Thrombolysis In Myocardial Infarction flow grade [2 points]). Three strata of risk were defined (low risk, score 0 to 2; intermediate risk, score 3 to 5; and high risk, score >/=6) with excellent prognostic accuracy for survival in the derivation and validation sets (c statistics = 0.83 and 0.81 for 30-day mortality and 0.79 and 0.78 for 1-year mortality, respectively). CONCLUSIONS: In AMI patients treated with primary PCI, seven risk factors readily available at the time of intervention accurately predict short- and long-term mortality. Of note, measurement of baseline left ventricular function is the single most powerful predictor of survival and should be incorporated into risk score models.

Aged↗
PubMed2005

In-hospital and long-term outcomes of multivessel percutaneous coronary revascularization after acute myocardial infarction.

Multivessel percutaneous coronary intervention (PCI) early after acute myocardial infarction (AMI) is discouraged because of the potential for increased complications. However, with recent advances in PCI, the safety and long-term outcomes of multivessel PCI are unknown. We evaluated the outcomes of multivessel PCI early after AMI (ST-elevation and non-ST-elevation AMI). We identified all patients who had multivessel disease and underwent PCI within 7 days after an AMI from 1997 to 2002. Clinical outcomes were compared between patients who underwent multivessel PCI (n = 239) and patients who underwent treatment of the infarct-related artery alone (n = 1,145). The primary end point was cumulative survival at 6, 12, and 36 months. Secondary end points included a composite of mortality, recurrent infarction, coronary artery bypass graft, or target vessel revascularization at the same time points. There were 138 deaths and 351 occurrences of the composite end point during follow-up. The multivessel PCI group had a significantly higher prevalence of adverse prognostic indicators. Despite this, observed event rates were similar between the multivessel PCI and 1-vessel PCI groups. The Kaplan-Meier estimated 1-year survival was 0.91 (95% confidence interval [CI] 0.87 to 0.95) for the multivessel PCI group and 0.93 (95% CI 0.92 to 0.95) for the 1-vessel PCI group (p = 0.43). Similarly, 1-year survival free of recurrent infarction and target vessel revascularization rates were similar between the 2 groups: multivessel PCI 0.78 (95% CI 0.73 to 0.84) and 1-vessel PCI 0.78 (95% CI 0.75 to 0.81). Multivessel PCI in patients with multivessel coronary artery disease after AMI compared with 1-vessel PCI was not associated with an excess risk of death or of combined death, myocardial infarction, coronary artery bypass graft, or target vessel revascularization.

Aged↗
PubMed2005

Predictive factors for ischemic target vessel revascularization in the Prevention of Restenosis with Tranilast and its Outcomes (PRESTO) trial.

OBJECTIVES: The aim of the present study was to determine the rates of target vessel revascularization (TVR) and to determine predictors of TVR from clinical and angiographic variables available in the Prevention of Restenosis With Tranilast and its Outcomes (PRESTO) database. BACKGROUND: The rates of TVR after percutaneous revascularization procedures, and its prediction with available clinical and angiographic variables, is less well known. METHODS: We studied nine-month TVR in 11,484 patients enrolled in the PRESTO trial. Clinical, lesion-related, and procedural characteristics were analyzed in a logistic regression model. Study data were divided at random into an 80% training set on which the models were developed and a 20% hold-out set on which the model properties were evaluated. RESULTS: A total of 14% (n = 1,609) had ischemic TVR. Clinical variables with increased risk for TVR included younger age; hypertension; diabetes mellitus; nonsmokers; unstable angina; previous coronary artery bypass grafting; peripheral vascular disease; procedure- and lesion-related such as ostial location, multilesion angioplasty, location in the left anterior descending artery, length > or =20 mm, in-stent restenosis at baseline, and use of rotablator. There was significant increase in the risk of ischemic TVR at U.S. treatment sites. Smoking and stent placement were associated with lower risk of ischemic TVR. The mean area (+/- SD) under the receiver-operating characteristic curve of the bootstrap samples was 0.66, indicating a modest ability of the model to discriminate patients who needed TVR on follow-up. CONCLUSIONS: Despite being the largest prospective trial designed to test restenosis, the discriminatory ability of the clinical and angiographic variables to predict TVR is modest.

Aged↗
PubMed2005

Addition of rectus sheath relaxation incisions to emergency midline laparotomy for peritonitis to prevent fascial dehiscence.

The incidence of fascial dehiscence and incisional hernia after two methods for abdominal wound closure (rectus sheath relaxation incisions and conventional mass closure) was studied in a randomized prospective clinical trial in a consecutive series of 100 patients undergoing midline laparotomy for peritonitis. The two groups were well matched for etiologies of peritonitis, the surgical procedures performed, and the presence of known risk factors for fascial dehiscence. Fifty patients each were randomized either to the conventional continuous mass closure procedure or the rectus sheath relaxation incision technique (designed to increase wound elasticity and decrease tension in the suture line) using identical polypropylene sutures. The incidence of postoperative complications such as duration of ileus, chest infection, and wound infection were not statistically different between the two groups. The intensity of postoperative pain in the rectus sheath relaxation incision group was significantly less. The incidence of wound hematoma was significantly increased in the rectus sheath relaxation incision group. The incidences of fascial dehiscence (16% vs,28%; p < 0.05) and incisional hernia (18% vs, 30%; p < 0.05) were significantly lower after rectus sheath relaxation incisions compared to conventional mass closure. Closure of the midline laparotomy wound in cases of peritonitis using the rectus sheath relaxation technique is safe and less painful, provides increased wound elasticity and decreased tension on the suture line, and significantly decreases the incidence of wound dehiscence.

Elasticity↗