Publications by authors named "Dipankar Bandyopadhyay"
Assessment of multistate disease progression is commonplace in biomedical research, such as in periodontal disease (PD). However, the presence of multistate current status endpoints, where only a single snapshot of each subject's progression through disease states is available at a random inspection time after a known starting state, complicates the inferential framework. In addition, these endpoints can be clustered, and spatially associated, where a group of proximally located teeth (within subjects) may experience similar PD status, compared to those distally located.
View Article and Find Full Text PDFRecent advances in sequencing technologies have allowed the collection of massive genome-wide information that substantially enhances the diagnosis and prognosis of head and neck cancer. Identifying predictive markers for survival time is crucial for devising prognostic systems and learning the underlying molecular drivers of the cancer course. In this paper, we introduce -KIDS, a model-free feature screening procedure with false discovery rate (FDR) control for ultrahigh-dimensional right-censored data, which is robust against unknown censoring mechanisms.
View Article and Find Full Text PDFBackground: Postmastectomy Radiotherapy (PMRT) has become standard of care for patients with breast cancer. However, local recurrence following breast conserving therapy is increasing in incidence due to increased survivorship. The relationship between prior radiation therapy, PMRT and immediate breast reconstruction (IBR) outcomes has not been widely studied.
View Article and Find Full Text PDFDeveloping protein-based drugs for oral administration is one of the most challenging aspects of research due to their low stability and inability to permeate through intestinal mucus barrier. Recent studies suggest that the ionic liquids (ILs) can combine with protein-based drugs to improve stability and mucus-penetration capabilities. However, the interactions among protein-based drugs, ILs, and mucin are rather unknown, which can play a pivotal role in such drug delivery.
View Article and Find Full Text PDFBackground: Higher levels of tumor-infiltrating lymphocytes (TILs) in breast cancers are associated with increased likelihood of pathologic complete response (pCR) to chemotherapy. DNA methyltransferase inhibitors (DNMTi) can augment immune responses to cancers, decreasing myeloid-derived suppressor cells (MDSCs) and increasing T lymphocyte responsiveness. We have shown that the DNMTi decitabine augments the effectiveness of immunotherapy using murine triple-negative breast cancer (TNBC) models.
View Article and Find Full Text PDFA phase I study of MLN4924 and belinostat in relapsed/refractory acute myeloid leukemia or myelodysplastic syndrome.
Cancer Chemother Pharmacol
January 2025
Article Synopsis
- The study investigates the combination of belinostat and pevonedistat in treating relapsed or refractory acute myeloid leukemia (AML) and high-risk myelodysplastic syndrome (MDS), showing promise in early-phase trials.
- Safety assessments found no dose-limiting toxicities, with some patients experiencing stable disease, while pharmacodynamics revealed increased levels of proteins associated with oxidative stress.
- The results may indicate potential therapeutic mechanisms relating to DNA damage response and oxidative damage, warranting further exploration in clinical settings.
Article Synopsis
- Self-organized contact line instabilities in liquid crystal droplets can create smaller liquid crystal drops through a unique locomotion phenomenon involving twin vortices when a volatile solvent droplet is introduced.
- The process is characterized by the rapid diffusion and evaporation of the solvent, leading to periodic oscillations at the droplet's contact line, forming finger-like structures.
- Eventually, these structured fingers break apart into miniaturized satellite droplets, with their spacing influenced by the elasticity of the liquid crystal, and the experiments reveal the roles of various forces in this locomotion.
The effect of Medicaid expansion on female gynecologic cancer-related inpatient admissions.
Womens Health (Lond)
December 2024
Article Synopsis
- The mortality rate of female gynecologic cancer is higher in those without affordable health insurance, leading to the exploration of Medicaid expansion's impact on admissions.
- In Virginia, where Medicaid was expanded in January 2019, the study compared gynecologic cancer-related hospital admissions to North Carolina, which did not expand Medicaid.
- Results showed a gradual increase in female gynecologic cancer admissions in Virginia after expansion, suggesting improved access to health services for Medicaid members due to previously unmet needs among uninsured individuals.
Article Synopsis
- KRAS G12C targeted therapies, like sotorasib, show limited effectiveness against lung cancer due to resistance mechanisms that reactivate ERK, requiring wild-type HRAS and NRAS.
- FGTI-2734, a dual inhibitor, prevents the movement of wild-type RAS to the cell membrane and counters sotorasib's resistance mechanisms, leading to enhanced cancer cell death.
- The combination of FGTI-2734 and sotorasib leads to significant tumor shrinkage in advanced lung cancer models and shows promise for targeting resistant cases.
Article Synopsis
- The paper introduces a new method for estimating censored quantile regression using inverse probability of censoring weighted (IPCW) methodology, which is suitable for partially interval-censored data often found in biomedical research for diseases like HIV/AIDS and cancer.
- The method addresses both doubly censored (DC) and partly interval-censored (PIC) data, offering a simpler and intuitive alternative to existing complex techniques by applying appropriate weights to subjects with known failure times.
- Simulation studies validate the performance of this approach, and it is demonstrated through an analysis of progression-free survival in a clinical trial for metastatic colorectal cancer.
Silver shelled gold nanorods for sensitive detection of cholesterol and triglycerides.
Biosens Bioelectron
January 2025
Article Synopsis
- The study details the creation of bimetallic plasmonic nanostructures (Ag-Au NRs) for selectively detecting cholesterol and triglycerides using Surface Enhanced Raman Spectroscopy (SERS).
- The gold nanorods were initially synthesized and then coated with a silver shell, resulting in enhanced SERS capabilities due to the combination of their plasmonic properties.
- The team immobilized different Raman reporter molecules on these nanostructures before attaching bioreceptors, enabling accurate quantification of cholesterol and triglycerides while demonstrating excellent selectivity against potential interferences.
Bayesian Variable Shrinkage and Selection in Compositional Data Regression: Application to Oral Microbiome.
J Indian Soc Probab Stat
May 2024
Article Synopsis
- Microbiome studies involve complex data that require specialized statistical models, like the Dirichlet-Multinomial (D-M) regression, for analyzing non-negative, bounded taxa counts.
- This paper introduces a Bayesian method for estimating significant associations between covariates and taxonomic abundance, focusing on continuous shrinkage priors like horseshoe and horseshoe+.
- The methodology shows strong performance in simulations and is applied to oral microbiome data, with code available on GitHub for further use.
Article Synopsis
- There is a notable sex bias in lung cancer mortality, with male patients experiencing more severe disease progression than female patients, suggesting potential for targeted therapies.
- Research using mouse models showed that this bias is influenced by factors such as functional ovaries and specific immune cell interactions, unlike other cancer types.
- The study highlights that using the Bcl-XL inhibitor navitoclax and targeting the TRAIL signaling pathway may offer a personalized treatment strategy for improving lung cancer outcomes in women.
Article Synopsis
- Recent advancements in sequencing technologies are improving the diagnosis and prognosis of head and neck cancer by providing extensive genome-wide data.
- The paper presents -KIDS, a novel method for screening predictive markers in ultrahigh dimensional right-censored data, which effectively controls false discovery rates.
- The methodology is validated using real head and neck cancer survival data from The Cancer Genome Atlas and is accessible through the R package DSFDRC on GitHub.
Article Synopsis
- The study presents a non-invasive micromixing method using the Lorentz force within a specially designed microchannel, leveraging the effects of electric and magnetic fields for enhanced mixing.
- Through computational fluid dynamics simulations, it examines factors like electrode size, distribution, and field intensity on the generation and strength of mixing vortices.
- Results indicate that localized wall heterogeneities can create controlled vortices, with alternating current electric fields offering additional control over vortex direction for efficient mixing of miscible fluids.
Article Synopsis
- The study investigates how annealing ferroelectric polymer thin films (P(VDF-TrFE) and P(VDF-TrFE-CFE)) under an electric field affects their crystalline structure and molecular orientation.
- Annealed films show enhanced ferroelectric properties, with poled P(VDF-TrFE) films displaying higher remnant and saturation polarization compared to unpoled versions, and lower coercive field values.
- Overall, the research highlights that electric field annealing significantly improves the electroactive and energy storage efficiency of these polymer films, making them more effective for applications.
Single-Index Mixed-Effects Model for Asymmetric Bivariate Clustered Data.
J Indian Soc Probab Stat
June 2024
Article Synopsis
- Researchers evaluate periodontal disease (PD) by examining the relationship between key clinical measurements, such as probed pocket depth (PPD) and clinical attachment level (CAL), but traditional linear models may lead to inaccurate conclusions due to non-linear relationships and normality assumptions.
- To address these issues, the study adopts a non-linear mixed model approach that considers both PPD and CAL responses as following an asymmetric Laplace distribution, allowing for a more accurate risk summary of PD.
- The proposed methodology, supported by a robust maximum-likelihood inferential framework and simulation studies, demonstrates effectiveness in handling complex data scenarios, including those with outliers, and is applied to a specific PD study involving Gullah-speaking African-American Type-2 diabetics.
Article Synopsis
- The study investigates how the volume of kidney transplant centers affects graft failure and patient mortality using data from over 219,000 transplantations in the U.S. from 2001 to 2015.
- It categorizes centers into quartiles based on their annual transplantation volume and assesses long-term outcomes, particularly focusing on deceased and living donor transplants.
- Results show that higher volume centers generally have lower rates of graft failure and patient mortality, especially for deceased donor transplants, highlighting the importance of center experience in improving transplant outcomes.
Article Synopsis
- A clinical trial assessed the combination of sorafenib tosylate, valproic acid, and sildenafil for recurrent high-grade glioma, reporting manageable toxicities and promising outcomes.
- The median progression-free survival was 3.65 months, and overall survival averaged 10.0 months, with some patients showing remarkable long-term survival beyond 73 months.
- Key findings indicated that low levels of the protein GRP78 were linked to better overall survival, highlighting the need for further development of this treatment approach.
Article Synopsis
- The study investigates lung cancer prevalence in Virginia by analyzing demographic, environmental, and socioeconomic factors at the zipcode level.
- It utilizes advanced statistical models to manage missing data and assess spatial relationships, revealing that higher smoking rates and social deprivation are linked to increased lung cancer cases.
- The findings indicate that lung cancer counts vary with racial demographics and age, showing higher rates among older populations and specific racial groups, thus enhancing knowledge about risk factors in the state.
Lactic Acid-Induced Colloidal Microrheology of Synovial Fluids.
Nayanjyoti Kakati
,
Dileep Ahari
,
Prathu Raja Parmar
,
Omkar Suresh Deshmukh
,
Dipankar Bandyopadhyay
ACS Biomater Sci Eng
May 2024
Article Synopsis
- The study investigates how colloidal scaffolds made of proteins and hyaluronic acid give synovial fluid its unique properties, helping joints withstand pressure and move smoothly.
- When the concentration of lactic acid increases due to conditions like hyperactivity or arthritis, these scaffolds break down, resulting in a significant reduction in the fluid's viscosity and elasticity, which lowers its protective capability for joint tissues.
- The researchers aim to create an artificial synovial fluid that mimics these characteristics, discovering that lactic acid plays a critical role in the breakdown of the scaffolds, a key element for developing effective synthetic alternatives.
Article Synopsis
- The study aimed to find the optimal phase 2 dose of regorafenib combined with sildenafil for patients with advanced solid tumors, while also evaluating their antitumor effects and potential toxicity.
- A phase 1, open-label trial was conducted, treating 29 patients with the recommended doses of regorafenib (160 mg daily) and sildenafil (100 mg daily), with the most common side effects being palmar-plantar erythrodysesthesia syndrome and hypophosphatemia.
- Although no objective responses were noted, nearly half of the patients experienced stable disease, particularly encouraging in cases of ovarian and cervical cancer, indicating the need for further studies in gynecologic cancers.
Partly linear single-index cure models with a nonparametric incidence link function.
Stat Methods Med Res
March 2024
Article Synopsis
- In cancer studies, some patients may not experience recurrence or death, and factors like treatment and demographics can influence survival and incidence rates.
- A mixture cure survival model is commonly used to analyze such data, combining logistic regression for incidence rates and the Cox proportional hazards model for latency, but traditional methods limit the flexibility of covariate effects in these components.
- To improve this flexibility, the article explores semiparametric mixture cure models using two single-index functions, proposing a hybrid nonparametric maximum likelihood estimation method and presenting results from simulations and real cancer datasets.
Article Synopsis
- Tumor budding (TB) refers to aggressive clusters of tumor cells found at the edge of invasive tumors, and their molecular behavior is not well understood.
- This study identifies CYTOR, a nuclear RNA, as a crucial regulator of TB characteristics, influencing stemness and a state known as partial epithelial-mesenchymal transition (p-EMT).
- By targeting CYTOR, researchers found a significant reduction in TB development and cancer progression in head and neck squamous cell carcinoma, suggesting that CYTOR could be a promising therapeutic target.
Article Synopsis
- Cancer therapies can lead to cardiac injury and increased cardiovascular disease risk, but the impact of diet on cardiac function in cancer survivors is not well understood.
- In a study involving 113 cancer survivors and 4,233 non-cancer controls, it was found that cancer survivors had a lower left ventricular ejection fraction (LVEF), indicating poorer heart function.
- A better quality diet, characterized by lower intake of unhealthy fats and higher intake of unsaturated fats and fiber, was linked to improved cardiac function among cancer survivors, while higher sucrose intake had a negative effect.
- Further research is necessary to confirm these results and explore whether dietary changes can enhance heart health in cancer survivors.