Modelling alternately recurring events using subject specific hazard estimation approach.

The motivation for this paper is to account for subject specific variations in a Cox proportional hazard model for alternating recurrent events. This is done through two sets of frailty components, whose marginal distributions are bound together by a copula function. The likelihood function involves unobservable variables, which requires the use of the EM algorithm. This leads to intractable integrals, which after some approximations, are solved using computationally intensive techniques. The results are applied to a real-life data. A simulation study is also carried out to check for consistency.

Comparative Effectiveness of Tofacitinib and Adalimumab in Axial Spondyloarthritis: A Real-World Clinical Context Multicenter Study.

INTRODUCTION: Tofacitinib, an oral Janus kinase inhibitor, is a putative choice in the treatment of axial spondyloarthritis (AxSpA). The objective of this study was to compare the effectiveness and tolerability of tofacitinib with adalimumab, in AxSpA, in a real-world clinical setting. METHODS: In this multicentric medical records review study, adult patients with active AxSpA treated with either tofacitinib 5 mg twice daily or adalimumab 40 mg subcutaneously fortnightly were recruited. Effectiveness was measured with Ankylosing Spondylitis Disease Activity Score (ASDAS) and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Drug-cost analysis was calculated with Incremental Cost-Effectiveness Ratio (ICER drug ). RESULTS: Among the 266 patients, 135 were treated with tofacitinib and 131 with adalimumab (follow-up: 6.5 ± 1.6 months). Mean improvement of BASDAI (3.39 ± 0.09 vs. 3.14 ± 1.16, respectively) and that of ASDAS (1.78 ± 0.68 vs. 2.07 ± 2.08, respectively) were comparable between the adalimumab and tofacitinib groups. A higher proportion of patients achieved BASDAI50 response in the second (49.5% vs. 31.6%) and fourth month (83.9% vs. 62.8%) and ASDAS low disease activity in the fourth month (71.6% vs. 47.9%) in the adalimumab group. All disease activity measurements were similar by the sixth month in both groups. A higher proportion of patients in the tofacitinib group than in the adalimumab group required change in therapy (14.8% vs. 7.6%, respectively). ICER drug for adalimumab compared with tofacitinib was US $188.8 per patient in the adalimumab group for each person-month with BASDAI <4. CONCLUSIONS: Tofacitinib showed comparable effectiveness with adalimumab in patients with AxSpA at the sixth month, despite lesser response in the initial months, with favorable ICER drug .

COPD and glycopyrronium responsiveness assessment: An appraisal.

Clinical Trial Registration: ECR/159/Inst/WB/2013/RR-20. Background: Glycopyrronium bromide (a long-acting antimuscarinic agent: LAMA) appears pharmacokinetically suitable for testing bronchodilator responsiveness as salbutamol (short-acting ß2-agonist: SABA). Exploring the feasibility, acceptability, degree of reversibility with glycopyrronium, and its comparison with that of salbutamol may be intriguing. Methods: New, consecutive, and willing outpatient attendees in the same season of the two consecutive years with chronic obstructive pulmonary disease (FEV1/FVC <0.07; FEV1 <80% of predicted) were subjected to serial responsiveness with inhalation of salbutamol first followed by 50 µg dry powder glycopyrronium [Salbutamol- Glycopyrronium] (phase-1) in the first year and glycopyrronium followed by salbutamol [Glycopyrronium- Salbutamol] (phase-2) in the following year. We looked for the acceptability, adverse reactions, and degree of changes in FEV1, FVC, FEV1/FVC, and FEF25-75 with comparison between the two groups. Results: The [Salbutamol- Glycopyrronium] group (n = 86) were similar in age, body mass index, and FEV1 to the [Glycopyrronium- Salbutamol] group (n = 88). Both the agents could make a significant (P <.0001) improvement in the parameters independently or as add-on when used serially in alternate orders. The intergroup difference at no stage was significant. The sensitive patients to salbutamol (n = 48), glycopyrronium (n = 44), and both (n = 12) have improvement of 165, 189, and 297 mL while a both-insensitive group (n = 70) had barely 44 mL of improvement. The protocol was universally accepted without any adverse events. Conclusion: Serial testing of salbutamol and glycopyrronium responsiveness in alternate orders provides an insight regarding the independent and the add-on effects of these two agents. About 40% of our chronic obstructive pulmonary disease patients had no clinically appreciable difference in FEV1 with the salbutamol + glycopyrronium combination inhalation.

The impact of lockdown on symptoms and health status of patients with chronic airway diseases: An appraisal of patient perceived impressions.

Background: The pandemic-specific lockdown may influence the health status of patients with chronic airflow obstruction (CAO) as COPD, COPD-PH, and chronic asthma. Objectives: To find the impact of the lockdown on symptoms, and the degree of perceived change in physical activity and emotional health with possible reasons including the indicators of ambient air pollution. Methods: A cohort of CAO patients was telephonically enquired regarding their perceived well-being in symptom status, physical activity, and emotional health with the perceived contribution from plausible reasons (regular medication, simple food, no pollution, and family attention) for the change; all being expressed in percentages. The change in symptom scores as 0-39, 40-79, and 80-100 were regarded as 'low', 'medium', and 'high' respectively. The impact of the individual contributing factor was calculated statistically. The assessment of the CAT (COPD assessment test) score and the ambient air pollution (PM2.5 and PM10) was also done for their association with well-being. Results: There was a universal improvement (p < 0.5) in COPD (n = 113), COPD-PH, (n = 40), and chronic asthma, (n = 19) as regards symptoms, physical activity, and emotional health that tallies to overall and individual change in CAT score. There were concomitant reductions in PM10 and PM2.5 levels during the lockdown compared to the same period of the previous year. All the four listed factors contributed with the 'no/low pollution' and 'simple food being the most important; on acting together, they reduced the moderate and severe symptoms impressively. Conclusion: Reduced air pollution and simple food appear most important for the improvement of CAO patients during the lockdown period.

Monitoring Fine and Associative Motor Learning in Mice Using the Erasmus Ladder.

Behavior is shaped by actions, and actions necessitate motor skills such as strength, coordination, and learning. None of the behaviors essential for sustaining life would be possible without the ability to transition from one position to another. Unfortunately, motor skills can be compromised in a wide array of diseases. Therefore, investigating the mechanisms of motor functions at the cellular, molecular, and circuit levels, as well as understanding the symptoms, causes, and progression of motor disorders, is crucial for developing effective treatments. Mouse models are frequently employed for this purpose. This article describes a protocol that allows the monitoring of various aspects of motor performance and learning in mice using an automated tool called the Erasmus Ladder. The assay involves two phases: an initial phase where mice are trained to navigate a horizontal ladder built of irregular rungs ("fine motor learning"), and a second phase where an obstacle is presented in the path of the moving animal. The perturbation can be unexpected ("challenged motor learning") or preceded by an auditory tone ("associative motor learning"). The task is easy to conduct and is fully supported by automated software. This report shows how different readouts from the test, when analyzed with sensitive statistical methods, allow fine monitoring of mouse motor skills using a small cohort of mice. We propose that the method will be highly sensitive to evaluate motor adaptations driven by environmental modifications as well as early-stage subtle motor deficits in mutant mice with compromised motor functions.

A systematic review and meta-analysis of mycobacterial infections in patients with idiopathic inflammatory myopathies.

OBJECTIVES: Infections including tuberculosis (TB) are a leading cause of morbidity and mortality in idiopathic inflammatory myopathies (IIM). We systematically reviewed the prevalence of mycobacterial infections in patients with IIM. METHODS: We screened PUBMED, EMBASE and SCOPUS databases and conference abstracts (2015-20) for original articles using Covidence. Pooled estimates of prevalence were calculated. RESULTS: Of 83 studies (28 cohort studies, two case control and 53 case reports), 19 were analysed. Of 14 043 IIM patients, DM (54.41%) was the most common subset among TB. Most studies were from Asia with high prevalence (5.86%, 2.33%-10.60%). Pooled prevalence of mycobacterial infections among IIM was 3.58% (95% CI: 2.17%, 5.85%, P < 0.01). Disseminated and extrapulmonary forms (46.58%; 95% CI: 39.02%, 54.31%, P = 1.00) were as common as pulmonary TB (49.07%; 95% CI: 41.43%, 56.75%, P =0.99) both for I2=0. Muscle involvement, an otherwise rare site, was frequently seen in case reports (24.14%). M. tuberculosis (28.84%) was the most common pathogen followed by Mycobacterium avium complex (3.25%). Non-tuberculous mycobacteria were less common overall (6.25; 95% CI: 3.49%, 10.93%) I2=0, P =0.94. Subgroup analysis and meta-regression based on high vs low TB regions found prevalence 6.61% (2.96%, 11.33%) in high TB regions vs 2.05% (0.90%, 3.56%) in low TB regions. While death due to TB was occasionally reported (P =0.82), successful anti-tubercular treatment was common (13.95%). CONCLUSION: TB is common in IIM, particularly in endemic regions though current data is largely heterogeneous. Extra-pulmonary forms and atypical sites including the muscle are frequent. Limited data suggests fair outcomes, although larger prospective studies may offer better understanding.

Efficacy and safety of intravenous and subcutaneous immunoglobulin therapy in idiopathic inflammatory myopathy: A systematic review and meta-analysis.

OBJECTIVE: To perform a systematic review and meta-analysis on the efficacy and safety of intravenous (IVIg) and subcutaneous (SCIg) immunoglobulin (Ig) therapy in the treatment of idiopathic inflammatory myopathy (IIM) and juvenile dermatomyositis (JDM). METHODS: PubMed, Embase and SCOPUS were searched to identify studies on Ig therapy in patients with IIM and/or JDM (2010-2020). Outcome measures were complete response (CR) or partial response (PR) in terms of muscle power and extramuscular disease activity measures on the International Myositis Assessment and Clinical Studies Group (IMACS) core set domains. RESULTS: Twenty-nine studies were included (n = 576, 544 IIM, 32 JDM). Muscle power PR with pooled Ig therapy was 88.5% (95% confidence interval (CI): 80.6-93.5, n = 499) and PR with SCIg treatment was 96.61% (95% CI: 87.43-99.15, n = 59). Pooled PR with first-line use of IVIg was 77.07% (95% CI: 61.25-92.89, n = 80). Overall, mean time to response was 2.9 months (95% CI: 1.9-4.1). Relapse was seen in 22.76% (95% CI: 14.9-33). Studies on cutaneous disease activity and dysphagia showed significant treatment responses. Glucocorticoid and immunosuppressant sparing effect was seen in 40.9% (95% CI: 20-61.7) and 42.2% (95% CI: 20.4-64.1) respectively. Ig therapy was generally safe with low risk of infection (1.37%, 95% CI: 0.1-2.6). CONCLUSIONS: Add-on Ig therapy improves muscle strength in patients with refractory IIM, but evidence on Ig therapy in new-onset disease and extramuscular disease activity is uncertain.

Oncogenic KRAS drives radioresistance through upregulation of NRF2-53BP1-mediated non-homologous end-joining repair.

KRAS-activating mutations are oncogenic drivers and are correlated with radioresistance of multiple cancers, including colorectal cancer, but the underlying precise molecular mechanisms remain elusive. Herein we model the radiosensitivity of isogenic HCT116 and SW48 colorectal cancer cell lines bearing wild-type or various mutant KRAS isoforms. We demonstrate that KRAS mutations indeed lead to radioresistance accompanied by reduced radiotherapy-induced mitotic catastrophe and an accelerated release from G2/M arrest. Moreover, KRAS mutations result in increased DNA damage response and upregulation of 53BP1 with associated increased non-homologous end-joining (NHEJ) repair. Remarkably, KRAS mutations lead to activation of NRF2 antioxidant signaling to increase 53BP1 gene transcription. Furthermore, genetic silencing or pharmacological inhibition of KRAS, NRF2 or 53BP1 attenuates KRAS mutation-induced radioresistance, especially in G1 phase cells. These findings reveal an important role for a KRAS-induced NRF2-53BP1 axis in the DNA repair and survival of KRAS-mutant tumor cells after radiotherapy, and indicate that targeting NRF2, 53BP1 or NHEJ may represent novel strategies to selectively abrogate KRAS mutation-mediated radioresistance.

Endemic infections, vaccinations, and variability of SARS-COV2 worldwide epidemiology: A cross-sectional study.

The present article aims to analyze epidemiologic aspects of the novel coronavirus pandemic (COVID-19) over different countries across the globe. While analyzing the overall spread of the disease, clusters of countries could be identified where the population-adjusted number of cases and mortality rates (MRs) were significantly different from the others. To draw a comparison over the countries at the same stage of infection, the nature and spread of the infection was evaluated at the 90th day of the pandemic for each country. It was observed that the countries with prevalent malarial transmission tended to have lesser population-adjusted COVID-19 caseloads. It was further observed that high population coverage of the Bacillus Calmette-Guérin vaccination was negatively associated with population-adjusted caseloads and MRs due to COVID-19. The present cross-sectional study is an attempt to bring in several social, economic, and structural confounders into understanding of the nature and spread of this novel pandemic globally.

Network theoretic analysis of JAK/STAT pathway and extrapolation to drugs and viruses including COVID-19.

Whenever some phenomenon can be represented as a graph or a network it seems pertinent to explore how much the mathematical properties of that network impact the phenomenon. In this study we explore the same philosophy in the context of immunology. Our objective was to assess the correlation of "size" (number of edges and minimum vertex cover) of the JAK/STAT network with treatment effect in rheumatoid arthritis (RA), phenotype of viral infection and effect of immunosuppressive agents on a system infected with the coronavirus. We extracted the JAK/STAT pathway from Kyoto Encyclopedia of Genes and Genomes (KEGG, hsa04630). The effects of the following drugs, and their combinations, commonly used in RA were tested: methotrexate, prednisolone, rituximab, tocilizumab, tofacitinib and baricitinib. Following viral systems were also tested for their ability to evade the JAK/STAT pathway: Measles, Influenza A, West Nile virus, Japanese B virus, Yellow Fever virus, respiratory syncytial virus, Kaposi's sarcoma virus, Hepatitis B and C virus, cytomegalovirus, Hendra and Nipah virus and Coronavirus. Good correlation of edges and minimum vertex cover with clinical efficacy were observed (for edge, rho = - 0.815, R2 = 0.676, p = 0.007, for vertex cover rho = - 0.793, R2 = 0.635, p = 0.011). In the viral systems both edges and vertex cover were associated with acuteness of viral infections. In the JAK/STAT system already infected with coronavirus, maximum reduction in size was achieved with baricitinib. To conclude, algebraic and combinatorial invariant of a network may explain its biological behaviour. At least theoretically, baricitinib may be an attractive target for treatment of coronavirus infection.

Rituximab in the treatment of systemic sclerosis-related interstitial lung disease: a systematic review and meta-analysis.

OBJECTIVES: To assess the effect of rituximab (RTX) on the lung function parameters in SSc interstitial lung disease (SSc-ILD) patients. METHODS: PubMed and Embase were searched to identify studies on SSc-ILD treated with RTX, confined to a predefined inclusion and exclusion criteria. A systematic review and meta-analysis were performed on the included studies on changes in forced vital capacity (FVC) and diffusion capacity of carbon monoxide (DLCO) from baseline to 6 and 12 months of follow-up. RESULTS: A total of 20 studies (2 randomized controlled trials, 6 prospective studies, 5 retrospective studies and 7 conference abstracts) were included (n = 575). RTX improved FVC from baseline by 4.49% (95% CI 0.25, 8.73) at 6 months and by 7.03% (95% CI 4.37, 9.7) at 12 months. Similarly, RTX improved DLCO by 3.47% (95% CI 0.99, 5.96) at 6 months and 4.08% (95% CI 1.51, 6.65) at 12 months. In the two studies comparing RTX with other immunosuppressants, improvement of FVC by 6 months in the RTX group was 1.03% (95% CI 0.11, 1.94) greater than controls. At the 12 month follow-up, RTX treatment was similar to controls in terms of both FVC and DLCO. Patients treated with RTX had a lower chance of developing infections compared with controls [odds ratio 0.256 (95% CI 0.104, 0.626), I2 = 0%, P = 0.47). CONCLUSIONS: Treatment with RTX in SSc-ILD was associated with a significant improvement of both FVC and DLCO during the first year of treatment. RTX use was associated with lower infectious adverse events.

High-resolution ultrasonography in carpal tunnel syndrome: role of ancillary criteria in diagnosis and response to steroid injection.

OBJECTIVES: (1) Development and validation of a composite ultrasound score (cUSS) for the diagnosis of carpal tunnel syndrome (CTS). (2) To predict treatment response after local corticosteroid injection. METHODS: Wrists of CTS patients and controls were evaluated with high-resolution ultrasound and cross-sectional area of median nerve at carpal tunnel inlet (CSAp) and outlet (CSAd) and bowing of flexor retinaculum (FRB), flexor tenosynovitis, and intraneural vascularity and echogenicity changes were noted. Patients were prospectively followed after ultrasound-guided corticosteroid injection. RESULTS: We studied 479 wrists of 141 patients and 99 controls. Optimal cut-offs for diagnosing CTS were 9.5 mm2 and 10.5 mm2, respectively, for CSAp and CSAd. A cUSS consisting of the following parameters was developed: age, CSAp, CSAd, FRB, and flexor tenosynovitis and echogenicity changes. External validation of cUSS yielded sensitivity, specificity, and diagnostic accuracy of 91.7%, 87.1%, and 89.8%, respectively. Treatment responses from 88 injections (median duration of follow-up of 6 months) were available with satisfactory initial responses in 69.32% (61/88) and relapses in 30.86% (25/81). Median time to relapse was 2 months. Initial response was predicted by FRB (odds ratio (OR): 5.43, 95% confidence interval (CI): 1.45-20.3, p = 0.012). Relapse was predicted by age (hazard ratio (HR) 1.168, 95% CI: 1.076-1.268, p = 0.0002), male gender (HR: 8.1.02, 95% CI: 2.394-27.422, p = 0.0007), FRB, (HR: 46.982, 95% CI: 5.048-437.293, p = 0.0008), and higher body mass index (HR: 0.238, 95% CI: 0.064-0.892, p = 0.0332). CONCLUSIONS: The developed cUSS has a diagnostic accuracy of 88% for diagnosing CTS. Ultrasound parameters could predict both initial treatment response and relapse. KEY POINTS: • Anatomical ultrasound parameters in addition to nerve cross-sectional area is important for diagnosis of CTS. • A composite US score for diagnosis of CTS was developed with accuracy 88.6%. • Bowing of flexor retinaculum predicts short and long term response to local steroid injection.

Effects of covariates on alternating recurrent events in accelerated failure time models.

In this article, we model alternately occurring recurrent events and study the effects of covariates on each of the survival times. This is done through the accelerated failure time models, where we use lagged event times to capture the dependence over both the cycles and the two events. However, since the errors of the two regression models are likely to be correlated, we assume a bivariate error distribution. Since most event time distributions do not readily extend to bivariate forms, we take recourse to copula functions to build up the bivariate distributions from the marginals. The model parameters are then estimated using the maximum likelihood method and the properties of the estimators studied. A data on respiratory disease is used to illustrate the technique. A simulation study is also conducted to check for consistency.

Psychological impact of COVID-19 pandemic on general population in West Bengal: A cross-sectional study.

BACKGROUND: COVID-19 pandemic poses a unique medical challenge to the humanity in recent times. The psychological impact of the pandemic itself and the lockdown in particular is likely to be huge. AIM: To assess the psychological impact of COVID-19 pandemic on general population in West Bengal. MATERIALS AND METHODS: It was an online survey which was conducted using Google Forms with link sent using WhatsApp. A 38-item self-designed questionnaire was used for the study. The survey questionnaire would take around 5-7 min to complete. Total 507 responses were received by the stipulated time. RESULTS: Near about five-seventh (71.8%) and one-fifth (24.7%) of the respondents felt more worried and depressed, respectively, in the past 2 weeks. Half of the respondents (52.1%) were preoccupied with the idea of contracting COVID-19 and one-fifth (21.1%) of the respondents were repeatedly thinking of getting themselves tested for the presence of COVID-19 despite having no symptoms. Majority (69.6%) of the respondents were worried about the financial loss they were incurring during the period of lockdown. One-fourth (25.6%) and one-third (30.8%) of the respondents found that COVID-19 pandemic had threatened their existence and they found it difficult to adjust to the new routine during 21-day lockdown period, respectively. CONCLUSION: The index survey suggested that worry and sleep disturbances were common among the respondents in the past 2 weeks. The pandemic threatened the existence of the respondents to a great extent and affected their mental status negatively.

Solvent-Assisted Tyrosine-Based Dipeptide Forms Low-Molecular Weight Gel: Preparation and Its Potential Use in Dye Removal and Oil Spillage Separation from Water.

Low-molecular weight gelators (supramolecular, or simply molecular gels) are highly important molecular frameworks because of their potential application in drug delivery, catalysis, pollutant removal, sensing materials, and so forth. Herein, a small dipeptide composed of N-(tert-butoxycarbonyl)pentafluoro-l-phenylalanine and O-benzyl-l-tyrosine methyl ester was synthesized, and its gelation ability was investigated in different solvent systems. It was found that the dipeptide was unable to form gel with a single solvent, but a mixture of solvent systems was found to be suitable for the gelation of this dipeptide. Interestingly, water was found to be essential for gelation with the polar protic solvent, and long-chain hydrocarbon units such as, petroleum ether, kerosene, and diesel, were important for gelation with aromatic solvents. The structural insights of these gels were characterized by field-emission scanning electronic microscopy, atomic force microscopy, Fourier transform infrared analysis, and X-ray diffraction studies, and their mechanical strengths were characterized by rheological experiments. Both of the gels obtained from these two solvent systems were thermoreversible in nature, and these translucent gels had potential application for the treatment of waste water. The gel obtained from dipeptides with methanol-water was used to remove toxic dyes (crystal violet, Eriochrome Black T, and rhodamine B) from water. Furthermore, the gel obtained from dipeptide with assistance from toluene-petroleum ether was used as a phase-selective gelator for oil-spill recovery.

A Clinicopathological and Immunofluorescence Study of Intraepidermal Immunobullous Diseases.

CONTEXT: Autoimmune blistering diseases (AIBDs) are characterized by autoantibodies directed against antigens of skin. Direct immunofluorescence (DIF) study helps in confirming the diagnosis where histopathology alone is noncontributory. AIMS: This study aimed to evaluate the clinicopathological and DIF features of intraepidermal AIBD and to assess their relative diagnostic significance. MATERIALS AND METHODS: It was an institution-based observational study. A total of 34 patients were studied over a period of 1½ years in the Department of Pathology in collaboration with the Department of Dermatology of a tertiary care hospital. The clinical, pathological, and DIF features were evaluated and documented. STATISTICAL ANALYSIS: Data were analyzed by statistical tests using GraphPad InStat. RESULTS: Pemphigus vulgaris (PV) was the predominant type with 18 (53%) cases followed by 15 (44%) cases of pemphigus foliaceus (PF) and a single case of pemphigus erythematosus (PE). The age of the patients ranged from 17 to 85 years. Overall, there was a female preponderance in the study group. The most common presenting feature was pruritus (58.82%). Tzanck smear showed the presence of acantholytic cells in thirty (88.24%) patients. Characteristic histopathological features were present in all the cases of PV and PF except one case of PF which was found to be a case of PE. DIF study showed intraepidermal deposition of intercellular immunoglobulin G (IgG) and C3 both in PV and PF. The case of PE showed epidermal "antinuclear antibody" staining with IgG. CONCLUSION: Immunofluorescence study may be used as an additional tool for confirmation of diagnosis where histopathology alone is inconclusive.

MicroRNA molecular profiling identifies potential signaling pathways conferring resistance to chemoradiation in locally-advanced rectal adenocarcinoma.

PURPOSE: There has been growing interest in using chemoradiation (CRT) for non-operative management of rectal cancer, and identifying patients who might benefit most from this approach is crucial. This study identified miRNAs (miRs) associated with clinical outcomes and treatment resistance by evaluating both pre- and post-CRT expression profiles. METHODS: Forty patients, 9 with pathologic complete response (pCR) and 31 with pathologic incomplete response (pIR) were included. MicroRNA was extracted from 40 pre-therapy tumor samples and 31 post-chemoradiation surgical samples with pathologic incomplete response (pIR). A generalized linear model was used to identify miRs associated with pCR. A linear mixed effects model was used to identify miRs differentially expressed before and after treatment. miR expression was dichotomized at the mean and clinical outcomes were evaluated using Cox proportional hazard modeling. RESULTS: Nine miRs were associated with pCR (p<0.05), but none were significant after false discovery rate correction. Among patients with pIR, 68 miRs were differentially expressed between the pre and post-CRT groups (FDR p<0.05). Ingenuity pathway analysis (IPA) demonstrated multiple signaling networks associated with pIR, including p38MAPK, TP53, AKT, IL-6, and RAS. Increased let-7b was correlated with increased distant metastasis (DM), worse relapse-free survival (RFS), and worse overall survival (OS) (p<0.05). CONCLUSIONS: No miRs were significantly correlated with pCR. We identified miRs that were differentially expressed between pre- and post-CRT tumor samples, and these miRs implicated multiple signaling pathways that may confer resistance to CRT. In addition, we identified an association between increased let-7b and worse clinical outcomes (DM, DFS, OS).

Caveolae-Mediated Endocytosis Is Critical for Albumin Cellular Uptake and Response to Albumin-Bound Chemotherapy.

Nab-paclitaxel, a nanoparticle conjugate of paclitaxel to human albumin, exhibits efficacy in pancreatic cancer, non-small cell lung cancer and breast cancer. However, there is a lack of predictive biomarkers to identify patients who might benefit most from its administration. This study addresses this gap in knowledge by identifying that caveolin-1 (Cav-1) is a candidate mechanism-based biomarker. Caveolae are small membrane invaginations important for transendothelial albumin uptake. Cav-1, the principal structural component of caveolae, is overexpressed in the cancers noted above that respond to nab-paclitaxel. Thus, we hypothesized that Cav-1 may be critical for albumin uptake in tumors and perhaps determine their response to this drug. Cav-1 protein levels correlated positively with nab-paclitaxel sensitivity. RNAi-mediated attenuation of Cav-1 expression reduced uptake of albumin and nab-paclitaxel in cancer cells and rendered them resistant to nab-paclitaxel-induced apoptosis. Conversely, Cav-1 overexpression enhanced sensitivity to nab-paclitaxel. Selection for cellular resistance to nab-paclitaxel in cell culture correlated with a loss of Cav-1 expression. In mouse xenograft models, cancer cells, where Cav-1 was attenuated, exhibited resistance to the antitumor effects of nab-paclitaxel therapy. Overall, our findings suggest Cav-1 as a predictive biomarker for the response to nab-paclitaxel and other albumin-based cancer therapeutic drugs. Cancer Res; 77(21); 5925-37. ©2017 AACR.

Formation of Annular Protofibrillar Assembly by Cysteine Tripeptide: Unraveling the Interactions with NMR, FTIR, and Molecular Dynamics.

Both hydrogen-bonding and hydrophobic interactions play a significant role in molecular assembly, including self-assembly of proteins and peptides. In this study, we report the formation of annular protofibrillar structure (diameter ∼500 nm) made of a newly synthesized s-benzyl-protected cysteine tripeptide, which was primarily stabilized by hydrogen-bonding and hydrophobic interactions. Atomic force microscopy and field emission scanning electron microscopy analyses found small oligomers (diameter ∼60 nm) to bigger annular (outer diameter ∼300 nm; inner diameter, 100 nm) and protofibrillar structures after 1-2 days of incubation. Rotating-frame Overhauser spectroscopic (ROESY) analysis revealed the presence of several nonbonded proton-proton interactions among the residues, such as amide protons with methylene group, aromatic protons with tertiary butyl group, and methylene protons with tertiary butyl group. These added significant stability to bring the peptides closer to form a well-ordered assembled structure. Hydrogen-deuterium exchange NMR measurement further suggested that two individual amide protons among the three amide groups were strongly engaged with the adjacent tripeptide via H-bond interaction. However, the remaining amide proton was found to be exposed to solvent and remained noninteracting with other tripeptide molecules. In addition to chemical shift values, a significant change in amide bond vibrations of the tripeptide was found due to the formation of the self-assembled structure. The amide I mode of vibrations involving two amide linkages appeared at 1641 and 1695 cm-1 in the solid state. However, in the assembled state, the stretching band at 1695 cm-1 became broad and slightly shifted to ∼1689 cm-1. On the contrary, the band at 1641 cm-1 shifted to 1659 cm-1 and indicated that the -C═O bond associated with this vibration became stronger in the assembled state. These changes in Fourier transform infrared spectroscopy frequency clearly indicated changes in the amide backbone conformation and the associated hydrogen-bonding pattern due to the formation of the assembled structure. In addition to hydrogen bonding, molecular dynamics simulation indicated that the number of π-π interactions also increased with increasing number of tripeptides participated in the self-assembly process. Combined results envisaged a cross ß-sheet assembly unit consisting of four intermolecular hydrogen bonds. Such noncovalent peptide assemblies glued by hydrogen-bonding and other weak forces may be useful in developing nanocapsule and related materials.