http://pucir.inflibnet.ac.in:8080/jspui/handle/123456789/733 2026-05-21T02:47:45Z 2026-05-21T02:47:45Z Pasupuleti, Samba Siva Rao http://pucir.inflibnet.ac.in:8080/jspui/handle/123456789/735 2024-06-14T09:17:34Z 2017-12-18T00:00:00Z

Title: A nonparametric regression-based linkage scan of rheumatoid factor-IgM using sib-pair squared sums and differences Authors: Pasupuleti, Samba Siva Rao Abstract: Parametric linkage methods for quantitative trait locus mapping require explicit specification of the probability model of the quantitative trait and hence can lead to misleading linkage inferences when the model assumptions are not valid. Ghosh and Majumder developed a nonparametric regression method based on kernel-smoothing for linkage mapping of quantitative trait locus using squared differences in trait values of independent sib pairs, which is relatively more robust than parametric methods with respect to violations in distributional assumptions. In this study, we modify the above mentioned nonparametric regression method by considering local linear polynomials instead of the Nadaraya-Watson estimator and squared sums of sib-pair trait values in addition to squared differences to perform a genome-wide scan of rheumatoid factor-IgM levels on sib pairs in the Genetic Analysis Workshop 15 simulated data set. We obtain significant evidence of linkage very close to the quantitative trait locus controlling for RF-IgM. We find that the simultaneous use of squared differences and squared sums increases the power to detect linkage compared to using only squared differences. However, because of all the sib pairs are selected for rheumatoid arthritis, there is reduced variance of RF-IgM values, and empirical power to detect linkage is not very high. We also compare the performance of our method with two linear regression approaches: the classical Haseman-Elston method using squared sib-pair trait differences and its extension proposed by Elston et al. using mean-corrected sib-pair cross-products. We find that the proposed nonparametric method yields more power than the linear regression approaches.

2017-12-18T00:00:00Z Pasupuleti, Samba Siva Rao http://pucir.inflibnet.ac.in:8080/jspui/handle/123456789/734 2024-06-14T09:13:45Z 2022-01-01T00:00:00Z

Title: Cytomegalovirus reactivation in seropositive critically ill patients with liver cirrhosis: A hospital-based longitudinal study Authors: Pasupuleti, Samba Siva Rao Abstract: Background: Cytomegalovirus (CMV) reactivation is known to occur among intensive care unit (ICU) patients. CMV-reactivation is not well-evaluated among critically ill cirrhotic adults who are not overtly immunocompro- mised. Objectives: Primary objective was to estimate the CMV-reactivation incidence rate among seropositive/latently infected critically ill cirrhotic adults. The secondary objective was to study the risk factors, host-related cytokine responses, and ICU outcomes associated with CMV-reactivation . Methods: In this longitudinal study conducted between November 2018 and June 2019, all consecutive anti- CMV-IgG-positive cirrhotic Liver-ICU patients were assessed at day 0/ICU-admission, day 7, 14, and 21 for CMV- reactivation/plasma-DNAemia ( ≥ 500 IU/ml), cytokines, clinical, laboratory and outcome parameters. Results: Fifty-five (48 male) cirrhosis patients consecutively admitted to liver-ICU were prospectively studied. Twenty (36%) adults developed CMV-reactivation. Majority (n = 17/55, 30.9%; 95% CI: 19.1 - 44.8) showed CMV- reactivation on ICU-day 7. CMV-reactivation incidence rate during 21-day follow-up was 2.75% per person-day (95% CI: 1.68-4.26% per person-day). None of the risk factors studied was independently associated with CMV- reactivation. Acute respiratory distress syndrome (p = 0.04), systemic inflammatory response syndrome (p = 0.01), secondary (bacterial and/or fungal) infections (p = 0.009), and raised pro-inflammatory cytokines (IFN 𝛾, p = 0.012; TNF 𝛼, p = 0.052) were observed concomitantly to CMV-reactivation on ICU-day 7. ICU-Mortality (n = 34/55, 61.8%) did not vary with a presence or absence of CMV-reactivation (55% versus 65.7%; p = 0.43). Length of stay (LOS) in liver-ICU did not differ concerning CMV-reactivation (5 days versus 4.5 days; p = 0.17) Conclusions: CMV-reactivation incidence rate was considerable among seropositive non-immunosuppressed crit- ically ill cirrhotic adults. Mortality and LOS in Liver-ICU were not significantly influenced by CMV-reactivation.

2022-01-01T00:00:00Z