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Vikas Gupta

Publications and source records attributed to Vikas Gupta.

At least 19 recordsLinked to original sources

UMI-nea: a fast, robust tool for reference-free UMI deduplication and accurate quantification.

MOTIVATION: One of the key applications of Unique Molecular Identifiers (UMIs) in high-throughput sequencing is to correct for PCR amplification bias and removal of PCR duplicates, thereby improving quantification in DNA-seq and RNA-seq applications. Accurately grouping error-bearing UMIs that originate from the same input molecule through a UMI deduplication method is a critical step in this process. However, many existing UMI deduplication tools rely on simple Hamming distance comparisons or suboptimal clustering algorithms, often resulting in erroneous UMI groupings, particularly in error-prone long-read sequencing or ultra-high-depth short-read sequencing. RESULTS: We introduce UMI-nea, a tool that utilizes Levenshtein distance comparisons and a novel clustering approach to optimize multithreading workflows. Compared against three other indel-aware UMI deduplication tools, UMI-nea achieves more accurate UMI groupings with efficient run time. It demonstrates robust performance across diverse sequencing platforms, depths, and UMI lengths. Additionally, UMI-nea incorporates a data-guided adaptive UMI filter, further enhancing quantification accuracy. AVAILABILITY AND IMPLEMENTATION: UMI-nea is available on github https://github.com/Qiaseq-research/UMI-nea.git or Zenodo https://doi.org/10.5281/zenodo.16745758. Sequencing data are stored at https://qiagenpublic.blob.core.windows.net/umi-nea-datasets/.

High-Throughput Nucleotide Sequencing↗

Morbidity and cost burden of methicillin-resistant Staphylococcus aureus in early onset ventilator-associated pneumonia.

INTRODUCTION: To gain a better understanding of the clinical and economic outcomes associated with methicillin-resistant Staphylococcus aureus (MRSA) infection in patients with early onset ventilator-associated pneumonia (VAP), we retrospectively analyzed a multihospital US database to identify patients with VAP over a 24 month period (2002-2003). METHOD: Data recorded included physiologic, laboratory, culture, and other clinical variables from 59 institutions. VAP was defined as new positive respiratory culture after at least 24 hours of mechanical ventilation (MV) and the presence of primary or secondary ICD-9-CM diagnosis codes of pneumonia. Outcomes measures included in-hospital morbidity and mortality for the population overall and after onset of VAP (duration of MV, intensive care unit [ICU] stay, in-hospital stay, and case mix and severity-adjusted operating cost). The overall cost was calculated at the hospital level using the Center for Medicare and Medicaid Services Cost/Charge Index for each calendar year. RESULTS: A total of 499 patients were identified as having VAP. S. aureus was the leading organism (31% of isolates). Patients with MRSA were significantly older than patients with methicillin-sensitive Staphylococcus aureus (MSSA; median age 74 versus 67 years, P < 0.05) and more likely to be medical patients. Compared with MSSA patients, MRSA patients on average consumed excess resources of 4.4 (95% confidence interval 0.6-8.2) overall MV days, 3.8 (-0.5 to +8.0) days of inpatient length of stay (LOS), 5.3 (1.0-9.7) ICU days, and US7731 dollars (-US8393 dollars to +US23,856 dollars) total cost after controlling for case mix and other factors. Furthermore, MRSA patients needed excess resources after the onset of VAP (4.5 [95% confidence interval 1.0-8.1] MV days, 3.7 [-0.5 to +8.0] inpatient days, and 4.4 [0.4-8.4] ICU days) after controlling for the same case mix and admission severity covariates. CONCLUSION: S. aureus remains a common cause of VAP. VAP due to MRSA was associated with increased overall LOS, ICU LOS, and attributable ICU LOS compared with MSSA-related VAP. Although not statistically significant because of small sample size and large variation, the attributable excess costs of MRSA amounted to approximately US8000 dollars per case after controlling for case mix and severity.

Aged↗

Cost analysis of erythropoietic-stimulating therapy dosing in oncology inpatients.

BACKGROUND: Inpatient costs associated with different erythropoietic-stimulating therapy regimens have not been compared in an oncology setting. OBJECTIVE: To conduct a cost analysis of different regimens of epoetin alfa (EPO) and darbepoetin alfa (DARB) in an inpatient oncology setting. METHODS: A retrospective evaluation of oncology diagnosis-related group discharges during 2003, in 30 community hospitals, identified EPO treatment patterns. Wholesale acquisition costs were determined for patients who received EPO 40,000 units or more once weekly. Potential differences in costs were calculated using conversion ratios for an equivalent EPO dose 3 times weekly or DARB dose once weekly (EPO:DARB ratio 260:1, approximating DARB 150 microg once weekly). A sensitivity analysis was performed using an EPO:DARB ratio of 400:1, approximating DARB 100 microg once weekly (1.5 microg/kg). RESULTS: Among the 1410 EPO doses administered (n = 677 pts.), a dose of 40,000 units or more was used 44% of the time (n = 311 pts.), with dosing initiated on average 5.6 days after admission. For these 311 evaluable patients, switching from EPO 40,000 units once weekly to EPO 10,000 units 3 times weekly reduced per-patient and total drug acquisition costs by approximately 50% (704 US dollars vs 359 US dollars and 218,938 US dollars vs 111,615 US dollars, respectively). Relative to EPO once weekly, switching patients to DARB resulted in increased drug acquisition costs at the 260:1 conversion and lower costs at the 400:1 conversion. However, EPO 3 times weekly remained the least costly option by 44-63%. The cost-savings realized with EPO 10,000 units 3 times weekly increased with longer duration of hospitalization. CONCLUSIONS: In an inpatient setting, use of EPO 10,000 units 3 times weekly may minimize expenditures associated with treatment of cancer-related anemia using erythropoietic-stimulating therapies.

Algorithms↗

Mesenteric hematoma mimicking a neoplasm--a case report.

Mesenteric hematoma is an uncommon condition. A 24-year-old man who underwent surgery for retroperitoneal leiomyosarcoma presented 9 months later with upper abdominal mass. Computerized tomography revealed a mesenteric mass in relation to proximal ileum. With a diagnosis of tumor recurrence, exploratory laparatomy was carried out, and the mass was resected out. Histology revealed an organized hematoma.

Adult↗

The role of diffusion-weighted imaging in the differential diagnosis of intracranial cystic mass lesions: a report of 147 lesions.

BACKGROUND: The objective of this study is to evaluate the sensitivity and specificity of DWI in differentiating brain abscesses from other intracranial cystic lesions. METHODS: One hundred fifteen patients with 147 cystic lesions (mean age, 26.4 year) were prospectively studied with DWI on a 1.5-T magnetic resonance imaging. Lesions appearing hyperintense on DWI with the ADC values of lower than 0.9 +/- 0.13 x 10(-3) mm(2)/s (mean +/- SD) were considered as brain abscess, whereas hypointense lesions on DWI with the ADC values 2.2 +/- 0.9 x 10(-3) mm(2)/s were categorized as nonabscess cystic lesions. RESULTS: Ninety-three of 97 brain abscess lesions were hyperintense on DWI, with significantly low (P = .0001) ADC value (0.87 +/- 0.05 x 10(-3) mm(2)/s) (mean +/- SEM), compared with 48 nonabscess lesions (2.89 +/- 0.05 x 10(-3) mm(2)/s). Four of 97 brain abscess lesions in 65 patients were false negative, and 2 of 50 nonabscess lesions in 50 patients were false positive for the diagnosis of brain abscess. The ADC value of the tumor cysts (2.9 +/- 0.05 x 10(-3) mm(2)/s) was significantly lower (P = .02) compared with benign cysts and neurocysticercosis (3.2 +/- 0.05 x 10(-3) mm(2)/s) among nonabscess group. The sensitivity of DWI for the differentiation of brain abscesses from nonabscesses was 96%; specificity, 96%; positive predictive value, 98%; negative predictive value, 92%; and accuracy of the test, 96%. CONCLUSIONS: Diffusion-weighted imaging has high sensitivity and specificity for the differentiation of brain abscess from other nonabscess intracranial cystic lesions.

Adolescent↗

Healthcare-associated bloodstream infection: A distinct entity? Insights from a large U.S. database.

OBJECTIVE: To gain a better understanding of the epidemiology, microbiology, and outcomes of early-onset, culture-positive, community-acquired, healthcare-associated, and hospital-acquired bloodstream infections. DESIGN: We analyzed a large U.S. database (Cardinal Health, MediQual, formerly MedisGroups) to identify patients with bacterial or fungal bloodstream isolates from 2002 to 2003. SETTING: The data set included administrative and clinical variables (physiologic, laboratory, culture, and other clinical) from 59 hospitals. Bloodstream infections were identified in those hospitals collecting clinical and culture data for at least the first 5 days of admission. PATIENTS: Patients with bloodstream infection within 2 days of admission were classified as having community-acquired bloodstream infection. Those with a prior hospitalization within 30 days, transfer from another facility, ongoing chemotherapy, or long-term hemodialysis were classified as having healthcare-associated bloodstream infection. Bloodstream infections that developed after day 2 of admission were classified as hospital-acquired bloodstream infection. A total of 6,697 patients were identified as having bloodstream infection. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Healthcare-associated bloodstream infection accounted for more than half (55.3%) of all bloodstream infections. Nearly two thirds (62.3%) of hospitalized patients with bloodstream infection suffered from either hospital-acquired bloodstream infection or healthcare-associated bloodstream infection and had higher morbidity and mortality rates than those with community-acquired bloodstream infection. Of all bloodstream infection pathogens, fungal organisms were associated with the highest crude mortality, longest length of stay in hospital, and greatest total charges. Of all bacterial bloodstream infections, methicillin-resistant Staphylococcus aureus was associated with the highest crude mortality rate (22.5%), the longest mean length of stay (11.1 +/- 10.7 days), and the highest median total charges ($36,109). After we controlled for confounding factors, methicillin-resistant S. aureus was associated with the highest independent mortality risk (odds ratio 2.70; confidence interval 2.03-3.58). S. aureus was the most commonly encountered pathogen in all types of early-onset bacteremia. CONCLUSIONS: Healthcare-associated bloodstream infection constitutes a distinct entity of bloodstream infection with its unique epidemiology, microbiology, and outcomes. Methicillin-resistant Staphylococcus aureus carries the highest relative mortality risk among all pathogens.

Aged↗

Clinical relevance of cytogenetic abnormalities at diagnosis of acquired aplastic anaemia in adults.

The outcome of 81 adult aplastic anaemia patients who had successful cytogenetics at diagnosis and received immunosuppressive therapy was evaluated. Ten patients had an abnormal karyotype, six of which had a trisomy. Four of five evaluable patients with a trisomy responded. One patient with monosomy 7 achieved a complete response and later developed haemolytic paroxysmal nocturnal haemoglobinuria but no recurrence of monosomy 7. None of the patients with a non-numerical karyotypic abnormality responded. No significant differences in survival or later clonal disorders were observed between patients with a normal karyotype and those with an abnormal karyotype.

Adolescent↗

Evaluation of the diagnostic efficacy of PCR for Ureaplasma urealyticum infection in Indian adults with symptoms of genital discharge.

Ureaplasma urealyticum genital infection may lead to severe clinical implications if left undiagnosed and untreated. The present study was conducted to evaluate the diagnostic efficiency of a polymerase chain reaction (PCR) assay and to determine the prevalence of U. urealyticum in Indian adults with symptoms of genital discharge. Cervical swabs, vaginal swabs and male urethral swabs from 100 patients attending an sexually transmitted disease clinic at a tertiary care hospital in Delhi were screened prospectively for infection with U. urealyticum. The prevalence of U. urealyticum was found to be 32% by culture and 45% by PCR. U. urealyticum was recovered from 8 (47%) and 37 (45%) symptomatic men and women, respectively. The agreement between PCR and culture was 93.75%. PCR improved the test sensitivity by 13% compared to culture. The results confirm the need to use a sensitive and reliable molecular method to prevent the underdiagnosis of ureaplasma infection and to facilitate better clinical management of this infection in India.

Colony Count, Microbial↗

Disease biology rather than age is the most important determinant of survival of patients > or = 60 years with acute myeloid leukemia treated with uniform intensive therapy.

BACKGROUND: The objectives of the current study were to evaluate the outcome of patients > or = 60 years with acute myeloid leukemia (AML) treated uniformly with high-dose daunorubicin containing induction and modified high-dose cytosine arabinoside containing postremission therapy, and to identify factors predictive of complete disease remission (CR) and survival. METHODS: Between 1998 and 2002, the authors treated 117 newly diagnosed patients (acute promyelocytic leukemia excluded) with AML > or = 60 years (median, 67 years; range, 60-82 years). Karyotype (Medical Research Council classification) at diagnosis was categorized as good risk (n = 3), intermediate risk (n = 69), adverse risk (n = 26), and suboptimal/not done (n = 19). A normal karyotype was seen in 41 patients and 40 (34%) had secondary AML. RESULTS: The outcome of induction included the following: CR, 62 (53%); early death, 5 (4%); death during hypoplasia, 14 (12%); and resistant disease, 36 (31%). The 3-year event-free (EFS) and overall survival (OS) rates were 9% (95% confidence interval [95% CI], 3-16%) and 17% (95% CI, 9-29%), respectively. In a univariate analysis, cytogenetics, lactate dehydrogenase level, leukocyte count, and performance status were the significant factors for EFS and OS. Age was not a significant prognostic factor for either CR or survival. In a multivariate model, adverse-risk cytogenetics, previous history of myelodysplastic syndrome or antecedent hematologic disorder, and high leukocyte count (> 30 x 10(9)/L) were independent adverse prognostic factors for survival. The impact of adverse karyotype on EFS and OS was time dependent and was observed after 50 and 150 days, respectively. CONCLUSIONS: The authors concluded that candidacy for intensive therapy in older patients should be based on biologic features of disease and fitness, rather than on age.

Acute Disease↗

Nonmyeloablative stem cell transplantation for myelodysplastic syndrome or acute myeloid leukemia in patients 60 years or older.

We analyzed the outcomes of 24 consecutive patients aged >or=60 years with poor-prognosis myelodysplastic syndrome or acute myeloid leukemia undergoing transplantation with nonmyeloablative conditioning using fludarabine (125 mg/m2) and low-dose total body irradiation (2 Gy) followed by allogeneic peripheral blood stem cell grafts from HLA-identical sibling donors. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and mycophenolate mofetil. The median age of the patients was 64 years (range, 60-71 years). In addition to age, 88% of patients had 1 or more adverse biological features of the disease. With a median follow-up of 21 months, 12 patients are alive, 11 of whom are disease free. The probabilities of 2-year overall and progression-free survival were 52% and 44%, respectively. The cumulative probabilities of relapse and of acute and chronic GVHD were 27%, 45%, and 74%, respectively. Nonrelapse mortality at 100 days and 2 years was 8% and 25%, respectively. Of the 15 patients with extensive chronic GVHD, 1 patient relapsed. These data suggest that nonmyeloablative stem cell transplantation is a feasible treatment option in patients aged >or=60 years with poor-prognosis myelodysplastic syndrome or acute myeloid leukemia. The reasonable disease control with nonmyeloablative transplantation in this high-risk group of patients merits further investigation.

Acute Disease↗

Role of all-trans-retinoic acid (ATRA) in the consolidation therapy of acute promyelocytic leukaemia (APL).

The role of all-trans-retinoic acid (ATRA) in the consolidation therapy of acute promyelocytic leukaemia (APL) is undefined at present. Between 1994 and 1999, we treated 38 newly diagnosed APL patients with ATRA and chemotherapy during the induction and consolidation. ATRA was given for 28 days each during the induction and 2 cycles of consolidation therapy. Chemotherapy consisted of daunorubicin and cytarabine. No maintenance therapy was given. ATRA was well-tolerated during consolidation therapy with no cases of retinoic acid syndrome. The 5-year overall and leukaemia-free survival of study patients was 82% (95% C.I. 70-95%) and 78% (95% C.I. 65-93%), respectively. These data are comparable to the studies that used prolonged maintenance with ATRA +/- chemotherapy. The role of ATRA during consolidation therapy of APL merits further investigation as this may allow shortening the overall duration of APL treatment.

Adolescent↗

Association of G-308A TNF-alpha polymorphism with bronchial asthma in a North Indian population.

Bronchial asthma is an inflammatory disorder in which genetic and environmental factors play an important role. Several susceptible genes have been identified using whole genome scan and candidate gene approaches. Tumor necrosis factor alpha, a pro-inflammatory cytokine, is one such gene that figures prominently in such investigations. The secreted levels of this cytokine are under genetic control and attributed to the presence of single nucleotide polymorphism G-308 A in the promoter region of its gene. However, the association of this polymorphism varies from population to population. As there are no data available on North Indians, the present study aims to fill this void. For this, 366 subjects (155 asthmatic and 211 normal control subject) were genotyped using Amplification Refractory Mutation System Analysis (ARMS-PCR) and agarose gel electrophoresis. The distribution of G/A alleles between the two groups revealed statistically significant differences (p = 0.016). Furthermore, the asthma patients categorized on the basis of pattern (Seasonal versus Perennial) and age of onset of disease (Childhood versus Late Onset) revealed significant association with only seasonal (p = 0.021) and late onset asthmatic groups (p = 0.039). The data from the present study strongly suggest an association between TNF-alpha and asthma in the North Indian population.

Asthma↗

Predictive value of karyotype on outcome of autotransplants for acute myeloid leukemia in second remission.

The impact of karyotype on the outcome of patients who undergo autotransplant for acute myeloid leukemia (AML) in second remission (CR2) has not been explored. We evaluated the outcomes of 40 patients who proceeded to autotransplant for AML in CR2 at 2 centers. The median age at autotransplant was 50 years (18-64 years) and the median duration of first remission was 15 months (0.8-51 months). High-dose therapy was melphalan 140-160 mg/m2 plus etoposide 60 mg/kg with or without total body irradiation (22), a busulfan-based regimen (17), and cyclophosphamide alone (1). Six patients (15%) died of treatment-related causes within the first 100 days. Event-free and overall survival at 3 years were both 38% (95% confidence interval 23-53%). At a median follow-up of 76 months (2?-?170) in surviving patients, 13 (32.5%) are alive and disease free. Graft purging did not significantly influence survival outcome (P=0.94), although platelet engraftment was significantly delayed (P=0.02). The relative risk of an event (relapse or death) for the karyotype risk groups was favorable 1.0; intermediate 4.2 (1.2-14.7); adverse 9.9 (1.5-63.9); unknown 2.3 (0.6-8.8) (P=0.028). We conclude that patients with AML in CR2 who undergo autotransplant can have durable remissions and those with a good risk karyotype are the most likely to obtain long-term disease-free survival.

Acute Disease↗

Neglected tendon and nerve injuries of the hand.

We retrospectively reviewed 445 patients with neglected tendon and nerve injuries treated between 1983 and 2003. Of these patients, 355 patients (447 tendons) had flexor tendon injuries, 62 patients (84 tendons) had extensor tendon injuries, and 28 patients had isolated nerve injuries. (In addition to these, 48 patients had nerve injuries associated with flexor tendon injuries; making a total of 76 patients with nerve injuries.) Most of the patients presented for treatment from 2 months to 2 years after the injury. The majority (73%) of patients with flexor tendon injuries were treated by free tendon grafting. Sixty-two patients required staged reconstruction using a silicon implant. The followup ranged from 12 to 83 months (mean, 45.8 months). In flexor tendon injuries, overall excellent results were seen in 83 of 447 tendons (18.5%) and good results were seen in 70.5%. In extensor tendon injuries, 23% had excellent results, 53% had good results, 34% had poor results. Seventy-six patients (114 nerves) of neglected nerve injuries of the hand were treated during the same period. In 48 (63%) patients the nerve injury was associated with tendon injury. End-to-end repair was possible in 89 nerves and the remainder was grafted. Because nerves in the hand have a predominant sensory component, sensory recovery was seen in the majority of patients.

Adolescent↗

A third course of anti-thymocyte globulin in aplastic anaemia is only beneficial in previous responders.

This retrospective study evaluated the outcome of 18 patients with aplastic anaemia treated with a third course of anti-thymocyte globulin (ATG)-containing immunosuppressive therapy (IST). Of the 18 patients, seven had responded to one of the previous courses of ATG and 11 were refractory to both the previous courses. Self-limiting grade >/=3 liver toxicity was observed in three patients. Two patients had to discontinue ATG because of severe systemic side effects. The incidence and manifestations of serum sickness did not appear to be different during the three courses. All of the seven patients that previously responded to one of the courses responded to a third course. In contrast, of 11 patients refractory to the previous courses, only two had a transient partial response. The 3-yr event-free survival for the patients who had responded to one of the previous courses of ATG was significantly superior to that of patients refractory to both the previous courses of ATG (83% vs. 0%, P = 0.0001). For aplastic anaemia patients, a third course of ATG-containing IST is a reasonable option in previous responders. Patients refractory to previous two courses of ATG have a much lower response rate and may be suitable candidates for novel therapeutic options.

Adolescent↗