Impact of Race and Social Determinants of Health on Outcomes in Patients with Aggressive B-cell nHL Treated with CAR-T

Healthcare disparities driven by multiple social, economic, and/or environmental factors lead to inequalities in health outcomes. CAR-T cell immunotherapy is an effective therapy for relapsed/refractory B-cell non-Hodgkin lymphoma (r/r B-NHL). However, data are limited on the impact of the convergence of race and social determinants of health on outcomes for patients treated with CAR-T therapy. We examined the impact of interactions between race and insurance type on health care utilization and outcomes in patients treated with CAR-T for aggressive B-NHL. Adult patients with r/r B-NHL treated with CD19 CAR-T were identified between 2015 and 2021 across 13 US academic centers. Insurance type, demographic and clinical data were collected and analyzed via Chi-squared and Kaplan-Meier analysis. Cox multivariable regression (MVA) was used to determine the impact of race/ethnicity and other variables on survival. 466 adult patients were included in our analysis. Median follow-up after CAR-T was 12.7 months. Median progression free survival (mPFS) was longer for Caucasians (11.5 months) than for African Americans (3.5 months, HR 1.56 [1.03-2.4], p=0.04) or Asians (2.7 months, HR 1.7 [1.02-2.67], p=0.04). Differences in median overall survival (mOS) were not significant. For Medicare (n=206) vs Medicaid (n=33) vs private insurance (n=219) vs self-pay (n=7): mPFS was 15.9 vs 4.2 vs 6.0 vs 0.9 months (p<0.001) and mOS was 31.2 vs 12.8 vs 21.5 vs 3.2 months (p<0.001), respectively. Collectively, our multi-center retrospective analysis showed that race and insurance status can impact outcomes for patients treated with CAR-T cell therapy.

Outcomes of limited stage primary bone diffuse large B-cell lymphoma in the rituximab era: a multicenter, retrospective study

Primary bone diffuse large B cell lymphoma (DLBCL) is a rare variant of extranodal non-Hodgkin lymphoma (NHL) historically treated with induction chemotherapy followed by consolidative radiation therapy (RT). It remains unknown whether RT confers additional benefit following rituximab-based chemoimmunotherapy (CIT) induction in patients with limited-stage disease. We conducted a multicenter retrospective analysis of patients treated between 2005 and 2019 using rituximab-based CIT regimens with or without consolidative RT to discern whether consolidative RT adds benefit in patients with stage I-II disease that could be encompassed in one radiation field. A total of 112 patients were included: 78 received CIT and radiation (RT group), and 34 received CIT alone (no RT group). The OS at 10 years was 77.9% in the RT group and 89.0% in the no RT group (p = 0.42). The RFS at 10 years was 73.5% in the RT group and 80.3% in the no RT group (p = 0.88). Neither improved OS nor RFS was associated with the addition of consolidative RT. Subgroup analysis of patients only achieving a partial response after CIT suggests that these patients may benefit from consolidative RT.

Beyond Bruton's tyrosine kinase inhibitors in mantle cell lymphoma: bispecific antibodies, antibody-drug conjugates, CAR T-cells, and novel agents

Mantle cell lymphoma is a B cell non-Hodgkin lymphoma (NHL), representing 2-6% of all NHLs and characterized by overexpression of cyclin D1. The last decade has seen the development of many novel treatment approaches in MCL, most notably the class of Bruton's tyrosine kinase inhibitors (BTKi). BTKi has shown excellent outcomes for patients with relapsed or refractory MCL and is now being studied in the first-line setting. However, patients eventually progress on BTKi due to the development of resistance. Additionally, there is an alteration in the tumor microenvironment in these patients with varying biological and therapeutic implications. Hence, it is necessary to explore novel therapeutic strategies that can be effective in those who progressed on BTKi or potentially circumvent resistance. In this review, we provide a brief overview of BTKi, then discuss the various mechanisms of BTK resistance including the role of genetic alteration, cancer stem cells, tumor microenvironment, and adaptive reprogramming bypassing the effect of BTK inhibition, and then provide a comprehensive review of current and emerging therapeutic options beyond BTKi including novel agents, CAR T cells, bispecific antibodies, and antibody-drug conjugates.

Peri-CAR-T practice patterns and survival predictors for all CAR-T patients and post-CAR-T failure in aggressive B-NHL

Most patients receiving chimeric antigen receptor T-cell therapy (CAR-T) for aggressive B-cell non-Hodgkin lymphoma (B-NHL) do not experience a durable remission. Several novel agents are approved to treat relapsed, refractory aggressive B-NHL; however, it remains unclear how to sequence these therapies pre- and post-CAR-T. We conducted a multicenter retrospective analysis to describe peri-CAR-T practice patterns and survival predictors for patients receiving CD19-directed CAR-T. Patients (n = 514) from 13 centers treated with CAR-T for B-NHL between 2015-2021 were included in the study. Survival curves were constructed using Kaplan-Meier method. Multivariate Cox regression analysis was used to determine the impact of the variables on survival outcomes. For all patients receiving CAR-T, a greater number of lines of therapy pre-CAR-T apheresis and bridging therapy were predictive of inferior progression-free survival (PFS) and overall survival (OS). The median PFS and OS from the time of CAR-T cell infusion were 7.6 and 25.6 months, respectively. From the time of progression post-CAR-T, the median OS was 5.5 months. The median PFS of treatments administered in the first-line post-CAR-T failure was 2.8 months. Patients with refractory disease on day 30 had inferior OS and were less likely to receive subsequent treatment(s) than other patients with CAR-T failure. Allogeneic hematopoietic cell transplantation for selected patients at any time following CAR-T failure led to durable responses in over half of patients at 1 year. These data provide a benchmark for future clinical trials in patients with post-CAR-T cell progression, which remains an unmet clinical need.

Impact of early relapse within 24 months after first-line systemic therapy (POD24) on outcomes in patients with marginal zone lymphoma: A US multisite study

Progression of disease within 24 months (POD24) from diagnosis in marginal zone lymphoma (MZL) was shown to portend poor outcomes in prior studies. However, many patients with MZL do not require immediate therapy, and the time from diagnosis-to-treatment interval can be highly variable with no universal criteria to initiate systemic therapy. Hence, we sought to evaluate the prognostic relevance of early relapse or progression within 24 months from systemic therapy initiation in a large US cohort. The primary objective was to evaluate the overall survival (OS) in the two groups. The secondary objective included the evaluation of factors predictive of POD24 and the assessment of cumulative incidence of histologic transformation (HT) in POD24 versus non-POD24 groups. The study included 524 patients with 143 (27%) in POD24 and 381 (73%) in non-POD24 groups. Patients with POD24 had inferior OS compared to those without POD24, regardless of the type of systemic therapy received (rituximab monotherapy or immunochemotherapy) at diagnosis. After adjusting for factors associated with inferior OS in the univariate Cox model, POD24 remained associated with significantly inferior OS (HR = 2.50, 95% CI = 1.53-4.09, p = 0.0003) in multivariable analysis. The presence of monoclonal protein at diagnosis and those who received first-line rituximab monotherapy had higher odds of POD24 on logistic regression analysis. Patients with POD24 had a significantly higher risk for HT compared to those without POD24. POD24 in MZL might be associated with adverse biology and could be used as an additional information point in clinical trials and investigated as a marker for worse prognosis.

Real-world evidence of the safety and survival with CD19 CAR-T cell therapy for relapsed/refractory solid organ transplant-related PTLD

The use of CD19 chimeric antigen receptor T-cell (CAR-T) therapy for relapsed/refractory solid organ transplantation (SOT)-related post-transplant lymphoproliferative disorder (PTLD) is not well studied. We conducted a multicentre, retrospective analysis of adults with relapsed/refractory SOT-associated PTLD. Among 22 relapsed/refractory SOT-PTLD patients, the pathology was monomorphic B cell. Prior SOTs included 14 kidney (64%), three liver (14%), two heart (9%), one intestinal (5%), one lung (5%), and one pancreas after kidney transplant (5%). The median time from SOT to PTLD diagnosis was 107 months. Pre-CAR-T bridging therapy was used in 55% of patients, and immunosuppression was stopped completely before CAR-T infusion in 64%. Eighteen (82%) patients experienced cytokine release syndrome: one (5%) each grade (G) 3 and G4. The immune effector cell-associated neurotoxicity syndrome was observed in 16 (73%) patients: six (27%) G3 and two (9%) G4. The overall response rate was 64% (55% complete response). Three patients (14%) experienced allograft rejection after CAR-T. The two-year progression-free survival and overall survival rates were 35% and 58%, respectively. Additionally, the achievement of CR post-CAR-T was strongly associated with survival. Collectively, the safety and efficacy of CD19 CAR-T therapy in relapsed/refractory SOT-related PTLD appeared similar to pivotal CAR-T data, including approximately one-third of patients achieving sustained remission.

Autologous hematopoietic cell transplantation versus whole-brain radiotherapy consolidation in primary central nervous system lymphoma: A systematic review and meta-analysis

The management of newly diagnosed primary central nervous system lymphoma (PCNSL) includes administration of high-dose methotrexate based regimens followed by consolidation therapy to minimize the risk of relapse. However, the best consolidation strategy (autologous hematopoietic cell transplant [auto-HCT] vs. whole-brain radiotherapy [WBRT]) is controversial. Hence, we performed a systematic review and meta-analysis of all randomized controlled trials that compared auto-HCT versus WBRT consolidation for patients with PCNSL after first-line treatment.The primary outcome was overall survival (OS), while the secondary outcomes included progression-free survival (PFS), response rates (overall response rate [ORR] and complete remission [CR]), relapse rate, treatment-related mortality (TRM), and neuropsychological adverse events. We performed a pooled analysis of the single-arm studies that incorporated auto-HCT or WBRT consolidation and evaluated neurocognitive outcomes. Only two studies met the inclusion criteria (n = 240). There was no significant difference in OS (HR = 1.50; 95% CI = 0.95-2.36), PFS (HR = 0.99; 95% CI = 0.44-2.22), ORR (RR = 1.48; 95% CI = 0.90-2.44), CR rate (RR = 1.21; 95% CI = 0.90-1.63), relapse rate (RR = 0.46; 95% CI = 0.05-4.28), and TRM (RR = 5.67; 95% CI = 1.01-31.91). The neuropsychological tests to assess neurocognitive domains were different and inconsistently reported in the two studies and therefore we were unable to perform a meta-analysis but provide a descriptive assessment. Both the studies showed a significant decline in the attention/executive function (based on the trail making test A and trail making test B) in those receiving WBRT compared to auto-HCT. We found 9 single-arm phase II studies that reported data on outcomes associated with either auto-HCT (5 studies) or WBRT (4 studies) consolidation. Of these, two studies (n = 43) reported data on neurocognitive decline following auto-HCT consolidation. Pooled proportion of patients with neurocognitive decline in these studies was 6% (95% CI, 0%-17%) for those receiving auto-HCT and there was no heterogeneity between studies (I²  = 0%). Three studies (n = 122) reported data on neurocognitive decline following WBRT consolidation. Pooled proportion of patients with neurocognitive decline in these studies was 43% (95% CI, 11%-78%) for those receiving WBRT and there was high heterogeneity between studies (I²  = 94%). There was significant heterogeneity between subgroups (p = 0.035). The outcomes were not significantly different in patients with PCNSL receiving auto-HCT or WBRT consolidation therapies, however, there is a higher degree of neurocognitive decline associated with WBRT compared to auto-HCT consolidation. The decision to choose a consolidation strategy needs to be individualized based on age, frailty, and co-morbidities.

Clinico-epidemiological Characteristics of Asymptomatic and Symptomatic COVID-19-Positive Patients in Bangladesh

As of August 15, 2020, Bangladesh lost 3591 lives since the first Coronavirus disease 2019 (COVID-19) case announced on March 8. The objective of the study was to report the clinical manifestation of both symptomatic and asymptomatic COVID-19-positive patients. An online-based cross-sectional survey was conducted for initial recruitment of participants with subsequent telephone interview by the three trained physicians in 237 adults with confirmed COVID-19 infection in Bangladesh. The study period was 27 April to 26th May 2020. Consent was ensured before commencing the interview. Collected data were entered in a pre-designed case record form and subsequently analyzed by SPSS 20.0. The mean±SD age at presentation was 41.59±13.73 years and most of the cases were male (73.0%). A total of 90.29% of patients reside in urban areas. Among the positive cases, 13.1% (n=31) were asymptomatic. Asymptomatic cases were significantly more common in households with 2 to 4 members (p=0.008). Both symptomatic and asymptomatic patients shared similar ages of presentation (p=0.23), gender differences (p=0.30) and co-morbidities (p=0.11). Only 5.3% of patients received ICU care during their treatment. The most frequent presentation was fever (88.3%), followed by cough (69.9%), chest pain (34.5%), body ache (31.1%), and sore throat (30.1%). Thirty-nine percent (n=92) of the patients had co-morbidities, with diabetes and hypertension being the most frequently observed. There has been an upsurge in COVID-19 cases in Bangladesh. Patients were mostly middle-aged and male. Typical presentations were fever and cough. Maintenance of social distancing and increased testing are required to meet the current public health challenge.

Predictive factors and outcomes for ibrutinib in relapsed/refractory marginal zone lymphoma: a multicenter cohort study

Ibrutinib is effective in the treatment of relapsed/refractory (R/R) marginal zone lymphoma (MZL) with an overall response rate (ORR) of 48%. However, factors associated with response (or lack thereof) to ibrutinib in R/R MZL in clinical practice are largely unknown. To answer this question, we performed a multicenter (25 US centers) cohort study and divided the study population into three groups: "ibrutinib responders"-patients who achieved complete or partial response (CR/PR) to ibrutinib; "stable disease (SD)"; and "primary progressors (PP)"-patients with progression of disease as their best response to ibrutinib. One hundred and nineteen patients met the eligibility criteria with 58%/17% ORR/CR, 29% with SD, and 13% with PP. The median PFS and OS were 29 and 71.4 months, respectively, with no difference in PFS or OS based on the ibrutinib line of therapy or type of therapy before ibrutinib. Patients with complex cytogenetics had an inferior PFS (HR = 3.08, 95% CI 1.23-7.67, p = 0.02), while those with both complex cytogenetics (HR = 3.00, 95% CI 1.03-8.68, p = 0.04) and PP (HR = 13.94, 95% CI 5.17-37.62, p < 0.001) had inferior OS. Only primary refractory disease to first-line therapy predicted a higher probability of PP to ibrutinib (RR = 3.77, 95% CI 1.15-12.33, p = 0.03). In this largest study to date evaluating outcomes of R/R MZL treated with ibrutinib, we show that patients with primary refractory disease and those with PP on ibrutinib are very high-risk subsets and need to be prioritized for experimental therapies.

An international analysis evaluating frontline bendamustine with rituximab in extranodal marginal zone lymphoma

Extranodal marginal zone lymphoma (EMZL) is a heterogeneous non-Hodgkin lymphoma. No consensus exists regarding the standard-of-care in patients with advanced-stage disease. Current recommendations are largely adapted from follicular lymphoma, for which bendamustine with rituximab (BR) is an established approach. We analyzed the safety and efficacy of frontline BR in EMZL using a large international consortium. We included 237 patients with a median age of 63 years (range, 21-85). Most patients presented with Eastern Cooperative Oncology Group (ECOG) performance status 0 to 1 (n = 228; 96.2%), stage III/IV (n = 179; 75.5%), and intermediate (49.8%) or high (33.3%) Mucosa Associated Lymphoid Tissue International Prognosis Index (MALT-IPI). Patients received a median of 6 (range, 1-8) cycles of BR, and 20.3% (n = 48) received rituximab maintenance. Thirteen percent experienced infectious complications during BR therapy; herpes zoster (4%) was the most common. Overall response rate was 93.2% with 81% complete responses. Estimated 5-year progression-free survival (PFS) and overall survival (OS) were 80.5% (95% CI, 73.1% to 86%) and 89.6% (95% CI, 83.1% to 93.6%), respectively. MALT-IPI failed to predict outcomes. In the multivariable model, the presence of B symptoms was associated with shorter PFS. Rituximab maintenance was associated with longer PFS (hazard ratio = 0.16; 95% CI, 0.04-0.71; P = .016) but did not impact OS. BR is a highly effective upfront regimen in EMZL, providing durable remissions and overcoming known adverse prognosis factors. This regimen is associated with occurrence of herpes zoster; thus, prophylactic treatment may be considered.

Differentiation of Solitary Mass Lesion of Brain using MR Spectroscopy with Histopathological Correlation

Different types of solitary brain lesions and also tumefactive demyelinating lesions exhibit many features on CT and MRI that are characteristics of malignancy and surgical biopsy is often performed in suspected tumour. Proton MR Spectroscopy has been used to differentiate different type of these solitary brain lesions. Our purpose is to determine whether MR spectroscopy is able to improve preoperative diagnostic accuracy in case of intracranial solitary tumors. This cross sectional study was carried out among 44 patients who were referred to Radiology and Imaging Department by Neurosurgery and Neuro-medicine department of BSMMU, Dhaka, Bangladesh as MRI suspected glioma for MRS scan during the period of 24 months. MRS was performed in 44 patients with suspected glioma. Metabolic ratio of choline: Cr, NAA: Cr, Lactate: Cr was calculated in short and intermediated echo times (TES). Tumors were subdivided into neoplasm and inflammatory mass. Neoplasm was again subdivided into glioblastoma multiforme and solitary metastasis. The patients were followed up and surgical resection biopsy reports were collected. MRS findings and histopathological findings were then correlated. In this study 68.18% of patients were diagnosed as Glioblastoma multiform by MRS and also in histopathology 18.18%. Patient was diagnosed as solitary metastasis in MRS and 20.45%. Patient was diagnosed as solitary metastasis by histopathology and 13.64%. Patient was diagnosed as abscess in MRS while in histopathology 11.37% patients were diagnosed as abscess.

Passive Cavitation Mapping by Cavitation Source Localization From Aperture-Domain Signals-Part II: Phantom and In Vivo Experiments

Passive cavitation mapping (PCM) techniques typically utilize a time-exposure acoustic (TEA) approach, where the received radio frequency data are beamformed, squared, and integrated over time. Such PCM-TEA cavitation maps typically suffer from long-tail artifacts and poor axial resolution with pulse-echo diagnostic arrays. Here, we utilize a recently developed PCM technique based on cavitation source localization (CSL), which fits a hyperbolic function to the received cavitation wavefront. A filtering method based on the root-mean-square error (rmse) of the hyperbolic fit is utilized to filter out spurious signals. We apply a wavefront correction technique to the signals with poor fit quality to recover additional cavitation signals and improve cavitation localization. Validation of the PCM-CSL technique with rmse filtering and wavefront correction was conducted in experiments with a tissue-mimicking flow phantom and an in vivo mouse model of cancer. It is shown that the quality of the hyperbolic fit, necessary for the PCM-CSL, requires an rmse < 0.05 mm² in order to accurately localize the cavitation sources. A detailed study of the wavefront correction technique was carried out, and it was shown that, when applied to experiments with high noise and interference from multiple cavitating microbubbles, it was capable of effectively correcting noisy wavefronts without introducing spurious cavitation sources, thereby improving the quality of the PCM-CSL images. In phantom experiments, the PCM-CSL was capable of precisely localizing sources on the therapy beam axis and off-axis sources. In vivo cavitation experiments showed that PMC-CSL showed a significant improvement over PCM-TEA and yielded acceptable localization of cavitation signals in mice.

Ultrasound and microbubble mediated therapeutic delivery: Underlying mechanisms and future outlook

Beyond the emerging field of oncological ultrasound molecular imaging, the recent significant advancements in ultrasound and contrast agent technology have paved the way for therapeutic ultrasound mediated microbubble oscillation and has shown that this approach is capable of increasing the permeability of microvessel walls while also initiating enhanced extravasation and drug delivery into target tissues. In addition, a large number of preclinical studies have demonstrated that ultrasound alone or combined with microbubbles can efficiently increase cell membrane permeability resulting in enhanced tissue distribution and intracellular drug delivery of molecules, nanoparticles, and other therapeutic agents. The mechanism behind the enhanced permeability is the temporary creation of pores in cell membranes through a phenomenon called sonoporation by high-intensity ultrasound and microbubbles or cavitation agents. At low ultrasound intensities (0.3-3 W/cm²), sonoporation may be caused by microbubbles oscillating in a stable motion, also known as stable cavitation. In contrast, at higher ultrasound intensities (greater than 3 W/cm²), sonoporation usually occurs through inertial cavitation that accompanies explosive growth and collapse of the microbubbles. Sonoporation has been shown to be a highly effective method to improve drug uptake through microbubble potentiated enhancement of microvascular permeability. In this review, the therapeutic strategy of using ultrasound for improved drug delivery are summarized with the special focus on cancer therapy. Additionally, we discuss the progress, challenges, and future of ultrasound-mediated drug delivery towards clinical translation.

Ibrutinib Resistance Mechanisms and Treatment Strategies for B-Cell lymphomas

Chronic activation of B-cell receptor (BCR) signaling via Bruton tyrosine kinase (BTK) is largely considered to be one of the primary mechanisms driving disease progression in B-Cell lymphomas. Although the BTK-targeting agent ibrutinib has shown promising clinical responses, the presence of primary or acquired resistance is common and often leads to dismal clinical outcomes. Resistance to ibrutinib therapy can be mediated through genetic mutations, up-regulation of alternative survival pathways, or other unknown factors that are not targeted by ibrutinib therapy. Understanding the key determinants, including tumor heterogeneity and rewiring of the molecular networks during disease progression and therapy, will assist exploration of alternative therapeutic strategies. Towards the goal of overcoming ibrutinib resistance, multiple alternative therapeutic agents, including second- and third-generation BTK inhibitors and immunomodulatory drugs, have been discovered and tested in both pre-clinical and clinical settings. Although these agents have shown high response rates alone or in combination with ibrutinib in ibrutinib-treated relapsed/refractory(R/R) lymphoma patients, overall clinical outcomes have not been satisfactory due to drug-associated toxicities and incomplete remission. In this review, we discuss the mechanisms of ibrutinib resistance development in B-cell lymphoma including complexities associated with genomic alterations, non-genetic acquired resistance, cancer stem cells, and the tumor microenvironment. Furthermore, we focus our discussion on more comprehensive views of recent developments in therapeutic strategies to overcome ibrutinib resistance, including novel BTK inhibitors, clinical therapeutic agents, proteolysis-targeting chimeras and immunotherapy regimens.

Impact and Intricacies of Bone Marrow Microenvironment in B-cell Lymphomas: From Biology to Therapy

Lymphoma, a group of widely prevalent hematological malignancies of lymphocyte origin, has become the focus of significant clinical research due to their high propensity for refractory/relapsed (R/R) disease, leading to poor prognostic outcomes. The complex molecular circuitry in lymphomas, especially in the aggressive phenotypes, has made it difficult to find a therapeutic option that can salvage R/R disease. Furthermore, the association of lymphomas with the Bone Marrow (BM) microenvironment has been found to portend worse outcomes in terms of heightened chances of relapse and acquired resistance to chemotherapy. This review assesses the current therapy options in three distinct types of lymphomas: diffuse large B-cell lymphoma, follicular lymphoma and mantle cell lymphoma. It also explores the role of the BM tumor microenvironment as a secure 'niche' for lymphoma cells to grow, proliferate and survive. It further evaluates potential mechanisms through which the tumor cells can establish molecular connections with the BM cells to provide pro-tumor benefits, and discusses putative therapeutic strategies for disrupting the BM-lymphoma cell communication.

Ultrasound-mediated delivery of miRNA-122 and anti-miRNA-21 therapeutically immunomodulates murine hepatocellular carcinoma in vivo

Hepatocellular carcinoma (HCC) is the most common cause of cancer-related mortality, and patients with HCC show poor response to currently available treatments, which demands new therapies. We recently developed a synthetic microRNA-based molecularly targeted therapy for improving HCC response to chemotherapy by eliminating drug resistance. We used ultrasound-targeted microbubble destruction (UTMD) to locally deliver microRNA-loaded nanoparticles to HCC. Since the immune microenvironment plays a crucial role in HCC disease development and response to treatment, and UTMD and microRNAs have the potential to interfere with the immune system, in this study we analyzed the immunomodulatory effects of UTMD and miRNAs in HCC. We used an immunocompetent syngeneic HCC mouse model for the study. We conducted cytokine profiling in tumor, lymph nodes, and serum of animals within the first 24 h of treatment to analyze changes in the level of pro- and antitumoral cytokines. The results showed: (1) Hepa1-6 syngeneic tumors expressed HCC-related cytokines, (2) UTMD-microRNA combination therapy triggered transient cytokine storms, and (3) delivery of microRNA-122 and anti-microRNA-21 affected the immune microenvironment by decreasing the level of GM-CSF in tumors while modulating protumoral IL-1α, IL-1β, IL-5, IL-6 and IL-17 and antitumoral IL-2 and IL-12 in tumor-proximal lymph nodes, and increasing IL-2 in the serum of tumor-bearing mice. Local delivery of targeted therapy by UTMD significantly reduced the concentration of IL-12 and IL-17 in lymph nodes of treated and contralateral tumors suggesting a systemic response. CONCLUSION: UTMD-mediated delivery of microRNA-122 and anti-microRNA-21 modulated the immune microenvironment of Hepa1-6 tumors at the level of cytokine expressions. Exploiting antitumoral immune effects could enhance the therapeutic efficacy of the proposed combination therapy for HCC.

Racial differences in myocardial deformation in obese children: Significance of inflammatory state

BACKGROUND AND AIMS

The association between racial differences in myocardial deformation and cardiometabolic risk factors is unknown in obese children. Our objective was to: 1) investigate for racial differences in myocardial deformation between white and black obese children and 2) identify biomarkers associated with these observed racial differences. We hypothesized that decreased myocardial deformation observed in black obese children could be accounted for by the differences in the markers of metabolic syndrome between the groups.

METHODS AND RESULTS

Obese children were recruited prospectively. All clinical and laboratory tests for the metabolic syndrome were conducted during a single assessment using a standardized protocol. Speckle-tracking echocardiography was performed to obtain longitudinal and circumferential measures of deformation. 310 patients were included in the analysis; 158 (51%) white and 152 (49%) black. The median age was 11.3 years (IQR 5.9). Blacks demonstrated worse longitudinal strain (-14.7 ± 2.7% vs. -15.4 ± 2.9%, p = 0.04). There was no difference in circumferential strain between the groups. Multivariable linear regression showed a significant relationship between longitudinal strain and hsCRP (β = 0.16, p = 0.03) and HOMA-IR (β = 0.15, p = 0.04); there was no independent association between longitudinal strain and race.

CONCLUSION

Black subjects demonstrated worse longitudinal strain than whites. Only hsCRP and HOMA-IR levels, not race, had an independent association with longitudinal strain, suggesting that the observed racial differences in longitudinal strain may be secondary to differences in inflammation and insulin resistance between the groups.

Longitudinal assessment of ultrasound-guided complementary microRNA therapy of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the second-leading cause of cancer related deaths worldwide and new strategies to efficiently treat HCC are critically needed. The aim of this study was to assess the longitudinal treatment effects of two complementary miRNAs (miRNA-122 and antimiR-21) encapsulated in biodegradable poly lactic-co-glycolic acid (PLGA) - poly ethylene glycol (PEG) nanoparticles (PLGA-PEG-NPs), administered by an ultrasound-guided and microbubble-mediated delivery approach in doxorubicin-resistant and non-resistant human HCC xenografts. Using in vitro assays, we show that repeated miRNA treatments resulted in gradual reduction of HCC cell proliferation and reversal of doxorubicin resistance. Optimized US parameters resulted in a 9-16 fold increase (p = 0.03) in miRNA delivery in vivo in HCC tumors after two US treatments compared to tumors without US treatment. Furthermore, when combined with doxorubicin (10 mg/kg), longitudinal miRNA delivery showed a significant inhibition of tumor growth in both resistant and non-resistant tumors compared to non-treated, and doxorubicin treated controls. We also found that ultrasound-guided miRNA therapy was not only effective in inhibiting HCC tumor growth but also allowed lowering the dose of doxorubicin needed to induce apoptosis. In conclusion, the results of this study suggest that ultrasound-guided and MB-mediated delivery of miRNA-122 and antimiR-21, when combined with doxorubicin, is a highly effective approach to treat resistant HCC while reducing doxorubicin doses needed for treating non-resistant HCC in longitudinal treatment experiments. Further refinement of this strategy could potentially lead to better treatment outcomes for patients with HCC.

Improved Sensitivity in Ultrasound Molecular Imaging With Coherence-Based Beamforming

Ultrasound molecular imaging (USMI) is accomplished by detecting microbubble (MB) contrast agents that have bound to specific biomarkers, and can be used for a variety of imaging applications, such as the early detection of cancer. USMI has been widely utilized in preclinical imaging in mice; however, USMI in humans can be challenging because of the low concentration of bound MBs and the signal degradation caused by the presence of heterogenous soft tissue between the transducer and the lesion. Short-lag spatial coherence (SLSC) beamforming has been proposed as a robust technique that is less affected by poor signal quality than standard delay-and-sum (DAS) beamforming. In this paper, USMI performance was assessed using contrast-enhanced ultrasound imaging combined with DAS (conventional CEUS) and with SLSC (SLSC-CEUS). Each method was characterized by flow channel phantom experiments. In a USMI-mimicking phantom, SLSC-CEUS was found to be more robust to high levels of additive thermal noise than DAS, with a 6dB SNR improvement when the thermal noise level was +6dB or higher. However, SLSC-CEUS was also found to be insensitive to increases in MB concentration, making it a poor choice for perfusion imaging. USMI performance was also measured in vivo using VEGFR2-targeted MBs in mice with subcutaneous human hepatocellular carcinoma tumors, with clinical imaging conditions mimicked using a porcine tissue layer between the tumor and the transducer. SLSC-CEUS improved the SNR in each of ten tumors by an average of 41%, corresponding to 3.0dB SNR. These results indicate that the SLSC beamformer is well-suited for USMI applications because of its high sensitivity and robust properties under challenging imaging conditions.

Ultrasound-guided drug delivery in cancer

Recent advancements in ultrasound and microbubble (USMB) mediated drug delivery technology has shown that this approach can improve spatially confined delivery of drugs and genes to target tissues while reducing systemic dose and toxicity. The mechanism behind enhanced delivery of therapeutics is sonoporation, the formation of openings in the vasculature, induced by ultrasound-triggered oscillations and destruction of microbubbles. In this review, progress and challenges of USMB mediated drug delivery are summarized, with special focus on cancer therapy.

Safety and Efficacy of A High Performance Graphene-Based Magnetic Resonance Imaging Contrast Agent for Renal Abnormalities

The etiology of renal insufficiency includes primary (e.g polycystic kidney disease) or secondary (e.g. contrast media, diabetes) causes. The regulatory restrictions placed on the use of contrast agents (CAs) for non-invasive imaging modalities such as X-ray computed tomography (CT) and magnetic resonance imaging (MRI) affects the clinical management of these patients. With the goal to develop a next-generation CA for unfettered use for renal MRI, here we report, in a rodent model of chronic kidney disease, the preclinical safety and efficacy of a novel nanoparticle CA comprising of manganese (Mn²⁺) ions intercalated graphene coated with dextran (hereafter called Mangradex). Nephrectomized rats received single or 5 times/week repeat (2 or 4 weeks) intravenous (IV) injections of Mangradex at two potential (low = 5 mg/kg, and high = 50 mg/kg) therapeutic doses. Histopathology results indicate that Mangradex does not elicit nephrogenic systemic fibrosis (NSF)-like indicators or questionable effects on vital organs of rodents. MRI at 7 Tesla magnetic field was performed on these rats immediately after IV injections of Mangradex at one potential therapeutic dose (25 mg/kg, [Mn²⁺] = 60 nmoles/kg) for 90 minutes. The results indicated significant (>100%) and sustained contrast enhancement in the kidney and renal artery at these low paramagnetic ion (Mn²⁺) concentration; 2 orders of magnitude lower than the paramagnetic ion concentration in a typical clinical dose of long circulating Gd³⁺-based MRI CA gadofosveset trisodium. The results open avenues for further development of Mangradex as a MRI CA to diagnose and monitor abnormalities in renal anatomy and vasculature.

Nanoparticle-Facilitated Membrane Depolarization-Induced Receptor Activation: Implications on Cellular Uptake and Drug Delivery

Cell-specific uptake of drug delivery systems (DDSs) are crucial to achieve optimal efficacy of many drugs. Widely employed strategies to facilitate targeted intracellular drug delivery involves attachment of targeting ligands (peptides or antibodies) to DDSs. Target receptors mutations can limit the effectiveness of this approach. Herein, we demonstrate, through in vitro inhibitory and drug delivery studies, that graphene nanoribbons (GNRs), water dispersed with the amphiphilic polymer called PEG-DSPE ((1, 2-distearoyl-sn-glycero-3-phosphoethanolamine-N [amino (polyethylene glycol)]) (induce membrane depolarization-mediated epidermal growth factor receptor (EGFR) activation. This phenomenon is ligand-independent and EGFR activation occurs via influx of Ca²⁺ ions from the extracellular space. We further provide evidence, through in vivo studies, that this mechanism could be exploited to facilitate efficacious drug delivery into tumors that overexpress EGFR. The results suggest that transient membrane depolarization-facilitated cell receptor activation can be employed as an alternate strategy for enhanced intracellular drug delivery.

Ultrasound-guided therapeutic modulation of hepatocellular carcinoma using complementary microRNAs

Treatment options for patients with hepatocellular carcinoma (HCC) are limited, in particular in advanced and drug resistant HCC. MicroRNAs (miRNA) are non-coding small RNAs that are emerging as novel drugs for the treatment of cancer. The aim of this study was to assess treatment effects of two complementary miRNAs (sense miRNA-122, and antisense antimiR-21) encapsulated in biodegradable poly (lactic-co-glycolic acid) nanoparticles (PLGA-NP), administered by an ultrasound-guided and microbubble-enhanced delivery approach in doxorubicin-resistant and non-resistant human HCC xenografts. Proliferation and invasiveness of human HCC cells after miRNA-122/antimiR-21 and doxorubicin treatment were assessed in vitro. Confocal microscopy and qRT-PCR were used to visualize and quantitate successful intracellular miRNA-loaded PLGA-NP delivery. Up and down-regulation of miRNA downstream targets and multidrug resistance proteins and extent of apoptosis were assessed in vivo in treated human HCC xenografts in mice. Compared to single miRNA therapy, combination therapy with the two complementary miRNAs resulted in significantly (P<0.05) stronger decrease in cell proliferation, invasion, and migration of HCC cells as well as higher resensitization to doxorubicin. Ultrasound-guided delivery significantly increased in vivo miRNA-loaded PLGA-NP delivery in human HCC xenografts compared to control conditions by 5-9 fold (P<0.001). miRNA-loaded PLGA-NP were internalized in HCC cells and anti-apoptotic proteins were down regulated with apoptosis in ~27% of the tumor volume of doxorubicin-resistant human HCC after a single treatment with complementary miRNAs and doxorubicin. Thus, ultrasound-guided delivery of complementary miRNAs is highly efficient in the treatment of doxorubicin- resistant and non-resistant HCC. Further development of this new treatment approach could aid in better treatment of patients with HCC.

Graphene-based platforms for cancer therapeutics

Graphene is a multifunctional carbon nanomaterial and could be utilized to develop platform technologies for cancer therapies. Its surface can be covalently and noncovalently functionalized with anticancer drugs and functional groups that target cancer cells and tissue to improve treatment efficacies. Furthermore, its physicochemical properties can be harnessed to facilitate stimulus responsive therapeutics and drug delivery. This review article summarizes the recent literature specifically focused on development of graphene technologies to treat cancer. We will focus on advances at the interface of graphene based drug/gene delivery, photothermal/photodynamic therapy and combinations of these techniques. We also discuss the current understanding in cytocompatibility and biocompatibility issues related to graphene formulations and their implications pertinent to clinical cancer management.

Correction: Changes in mangrove species assemblages and future prediction of the Bangladesh Sundarbans using Markov chain model and cellular automata

Correction for ‘Changes in mangrove species assemblages and future prediction of the Bangladesh Sundarbans using Markov chain model and cellular automata’ by Anirban Mukhopadhyay et al., Environ. Sci.: Processes Impacts, 2015, 17, 1111–1117.

Interaction of graphene nanoribbons with components of the blood vascular system

AIM

The systemic administration of graphene nanoribbons for a variety of in vivo biomedical applications will result in their interaction with cellular and protein components of the circulatory system. The aim of this study was to assess the in vitro effects of graphene nanoribbons (O-GNR) noncovalently functionalized with PEG-DSPE (1, 2-distearoyl-sn-glycero-3-phosphoethanolamine-N [amino (polyethylene glycol)]) on some of the key hematological and vascular components of the circulatory system.

METHODS

Transmission electron microscopy was used to characterize the nanoparticles. ELISA-based assays, bright-field microscopy, transmission electron microscopy and colorimetric assays were used to assess toxicological effects.

RESULTS

Our findings taken together indicate that low concentrations of O-GNR-PEG-DSPE (<80 μg/ml) are relatively nontoxic to the hematological components, and could be employed for diagnostic and therapeutic applications especially for diseases of the circulatory system. Graphene nanoribbons are a class of carbon-based nanostructures derived from multiwalled carbon nanotubes that have been shown to have unique properties and high potential for drug-delivery applications in recent studies from our group. However, further development of this nanoparticle for biomedical applications will be possible only after its interactions with components of the circulatory system are suitably characterized. Toward that goal, this study is aimed at identifying potential toxicities of graphene nanoribbons in the circulatory system. Results from this study will give us indications about safe dosages and lay the foundation toward further animal studies.

Changes in mangrove species assemblages and future prediction of the Bangladesh Sundarbans using Markov chain model and cellular automata

The composition and assemblage of mangroves in the Bangladesh Sundarbans are changing systematically in response to several environmental factors. In order to understand the impact of the changing environmental conditions on the mangrove forest, species composition maps for the years 1985, 1995 and 2005 were studied. In the present study, 1985 and 1995 species zonation maps were considered as base data and the cellular automata-Markov chain model was run to predict the species zonation for the year 2005. The model output was validated against the actual dataset for 2005 and calibrated. Finally, using the model, mangrove species zonation maps for the years 2025, 2055 and 2105 have been prepared. The model was run with the assumption that the continuation of the current tempo and mode of drivers of environmental factors (temperature, rainfall, salinity change) of the last two decades will remain the same in the next few decades. Present findings show that the area distribution of the following species assemblages like Goran (Ceriops), Sundari (Heritiera), Passur (Xylocarpus), and Baen (Avicennia) would decrease in the descending order, whereas the area distribution of Gewa (Excoecaria), Keora (Sonneratia) and Kankra (Bruguiera) dominated assemblages would increase. The spatial distribution of projected mangrove species assemblages shows that more salt tolerant species will dominate in the future; which may be used as a proxy to predict the increase of salinity and its spatial variation in Sundarbans. Considering the present rate of loss of forest land, 17% of the total mangrove cover is predicted to be lost by the year 2105 with a significant loss of fresh water loving mangroves and related ecosystem services. This paper describes a unique approach to assess future changes in species composition and future forest zonation in mangroves under the 'business as usual' scenario of climate change.

Graphene nanoribbons elicit cell specific uptake and delivery via activation of epidermal growth factor receptor enhanced by human papillomavirus E5 protein

Ligands such as peptides, antibodies or other epitopes bind and activate specific cell receptors, and are employed for targeted cellular delivery of pharmaceuticals such as drugs, genes and imaging agents. Herein, we show that oxidized graphene nanoribbons, non-covalently functionalized with PEG-DSPE (1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N[amino(polyethyleneglycol)]) (O-GNR-PEG-DSPE) activate epidermal growth factor receptors (EGFRs). This activation generates a predominantly dynamin-dependent macropinocytosis-like response, and results in significant O-GNR-PEG-DSPE uptake into cells with high EGFR expression. Cells with an integrated human papillomavirus (HPV) genome also show increased uptake due to the modulation of the activated EGFR by the viral protein E5. We demonstrate that this cell specific uptake of O-GNR-PEG-DSPE can be exploited to achieve significantly enhanced drug efficacies even in drug resistant cells. These results have implications for the development of active targeting and delivery agents without ligand functionalization for use in the diagnosis and treatment of pathologies that overexpress EGFR or mediated by HPV.

Graphene nanoribbons as a drug delivery agent for lucanthone mediated therapy of glioblastoma multiforme

We report use of PEG-DSPE coated oxidized graphene nanoribbons (O-GNR-PEG-DSPE) as agent for delivery of anti-tumor drug Lucanthone (Luc) into Glioblastoma Multiformae (GBM) cells targeting base excision repair enzyme APE-1 (Apurinic endonuclease-1). Lucanthone, an endonuclease inhibitor of APE-1, was loaded onto O-GNR-PEG-DSPEs using a simple non-covalent method. We found its uptake by GBM cell line U251 exceeding 67% and 60% in APE-1-overexpressing U251, post 24h. However, their uptake was ~38% and 29% by MCF-7 and rat glial progenitor cells (CG-4), respectively. TEM analysis of U251 showed large aggregates of O-GNR-PEG-DSPE in vesicles. Luc-O-GNR-PEG-DSPE was significantly toxic to U251 but showed little/no toxicity when exposed to MCF-7/CG-4 cells. This differential uptake effect can be exploited to use O-GNR-PEG-DSPEs as a vehicle for Luc delivery to GBM, while reducing nonspecific cytotoxicity to the surrounding healthy tissue. Cell death in U251 was necrotic, probably due to oxidative degradation of APE-1.

Dose ranging, expanded acute toxicity and safety pharmacology studies for intravenously administered functionalized graphene nanoparticle formulations

Graphene nanoparticle dispersions show immense potential as multifunctional agents for in vivo biomedical applications. Herein, we follow regulatory guidelines for pharmaceuticals that recommend safety pharmacology assessment at least 10-100 times higher than the projected therapeutic dose, and present comprehensive single dose response, expanded acute toxicology, toxicokinetics, and respiratory/cardiovascular safety pharmacology results for intravenously administered dextran-coated graphene oxide nanoplatelet (GNP-Dex) formulations to rats at doses between 1 and 500 mg/kg. Our results indicate that the maximum tolerable dose (MTD) of GNP-Dex is between 50 mg/kg ≤ MTD < 125 mg/kg, blood half-life < 30 min, and majority of nanoparticles excreted within 24 h through feces. Histopathology changes were noted at ≥250 mg/kg in the heart, liver, lung, spleen, and kidney; we found no changes in the brain and no GNP-Dex related effects in the cardiovascular parameters or hematological factors (blood, lipid, and metabolic panels) at doses < 125 mg/kg. The results open avenues for pivotal preclinical single and repeat dose safety studies following good laboratory practices (GLP) as required by regulatory agencies for investigational new drug (IND) application.

Vasoactive effects of stable aqueous suspensions of single walled carbon nanotubes in hamsters and mice

Single-walled carbon nanotubes synthesized with iron (Fe-SWCNT) or gadolinium (Gd-SWCNT) show promise as high performance multimodal contrast and drug-delivery agents. Our purpose was to evaluate potential vasoactive effects of SWCNT. Stable aqueous solutions of Fe-SWCNTs or Gd-SWCNTs were made using the biocompatible amphiphilic polymer N-(carbonyl-methoxypolyethyleneglycol 2000)-1,2-distearoylsn-glycero-3- phosphoethanolamine (PEG-DSPE). Both aggregated and non-aggregated (sonicated) formulations were tested. The initial vasoactivity of the formulations and their potential for inducing pro-inflammatory endothelial dysfunction were investigated in the hamster cheek pouch and murine cremaster muscle intravital microscopy models. These models provide an assay to test several formulations/dosages in a paired fashion. Abluminal exposure to small arterioles exposes both endothelial and vascular smooth muscle cells. Using abluminal exposures of dosages that would approximate the first pass of an i.v. bolus injection, both Fe-SWCNTs and Gd-SWCNTs were immediately vasoactive. Aggregated formulations induced dilation and non-aggregated formulations induced constriction in both hamsters and mice. Endothelial dysfunction was evident after exposure to either aggregated or non-aggregated forms. General loss of dilator capability was seen after exposure to non-aggregated but not aggregated forms. Thus concentrations mimicking bolus dosing of PEG-DSPE coated SWCNT induce both acute and chronic vascular responses.

Physicochemical characterization of a novel graphene-based magnetic resonance imaging contrast agent

We report the synthesis and characterization of a novel carbon nanostructure-based magnetic resonance imaging contrast agent (MRI CA); graphene nanoplatelets intercalated with manganese (Mn²⁺) ions, functionalized with dextran (GNP-Dex); and the in vitro assessment of its essential preclinical physicochemical properties: osmolality, viscosity, partition coefficient, protein binding, thermostability, histamine release, and relaxivity. The results indicate that, at concentrations between 0.1 and 100.0 mg/mL, the GNP-Dex formulations are hydrophilic, highly soluble, and stable in deionized water, as well as iso-osmolar (upon addition of mannitol) and iso-viscous to blood. At potential steady-state equilibrium concentrations in blood (0.1–10.0 mg/mL), the thermostability, protein-binding, and histamine-release studies indicate that the GNP-Dex formulations are thermally stable (with no Mn²⁺ ion dissociation), do not allow non-specific protein adsorption, and elicit negligible allergic response. The r₁ relaxivity of GNP-Dex was 92 mM⁻¹s⁻¹ (per-Mn²⁺ ion, 22 MHz proton Larmor frequency); ~20- to 30-fold greater than that of clinical gadolinium (Gd³⁺)- and Mn²⁺-based MRI CAs. The results open avenues for preclinical in vivo safety and efficacy studies with GNP-Dex toward its development as a clinical MRI CA.

Cell specific cytotoxicity and uptake of graphene nanoribbons

The synthesis of oxidized graphene nanoribbons (O-GNR) via longitudinal unzipping of carbon nanotubes opens avenues for their further development for a variety of biomedical applications. Evaluation of the cyto- and bio-compatibility is necessary to develop any new material for in vivo biomedical applications. In this study, we report the cytotoxicity screening of O-GNRs water-solubilized with PEG-DSPE (1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)]), using six different assays, in four representative cell lines; Henrietta Lacks cells (HeLa) derived from cervical cancer tissue, National Institute of Health 3T3 mouse fibroblast cells (NIH-3T3), Sloan Kettering breast cancer cells (SKBR3) and Michigan cancer foundation-7 breast cancer cells (MCF7). These cell lines significantly differed in their response to O-GNR-PEG-DSPE formulations; assessed and evaluated using various endpoints (lactate dehydrogenase (LDH) release, cellular metabolism, lysosomal integrity and cell proliferation) for cytotoxicity. In general, all the cells showed a dose-dependent (10-400 μg/ml) and time-dependent (12-48 h) decrease in cell viability. However, the degree of cytotoxicity was significantly lower in MCF7 or SKBR3 cells compared to HeLa cells. These cells were 100% viable upto 48 h, when incubated at 10 μg/ml O-GNR-PEG-DSPE concentration, and showed decrease in cell viability above this concentration with ~78% of cells viable at the highest concentration (400 μg/ml). In contrast, significant cell death (5-25% cell death depending on the time point, and the assay) was observed for HeLa cells even at a low concentration of 10 μg/ml. The decrease in cell viability was steep with increase in concentration with the CD(50) values ≥ 100 μg/ml depending on the assay, and time point. Transmission electron microscopy of the various cells treated with the O-GNR solutions show higher uptake of the O-GNR-PEG-DSPEs into HeLa cells compared to other cell types. Additional analysis indicates that this increased uptake is the dominant cause of the significantly higher toxicity exhibited by HeLa cells. The results suggest that water-solubilized O-GNR-PEG-DSPEs have a heterogenous cell-specific cytotoxicity, and have significantly different cytotoxicity profile compared to graphene nanoparticles prepared by the modified Hummer's method (graphene nanoparticles prepared by oxidation of graphite, and its mechanical exfoliation) or its variations.

Non-fatal burn is a major cause of illness: findings from the largest community-based national survey in Bangladesh

OBJECTIVE

To examine the incidence and characteristics of non-fatal burn injury in Bangladesh.

METHODS

A population-based cross-sectional survey was conducted between January and December 2003 in Bangladesh. Nationally representative data were collected from 171 366 rural and urban households, with a total sample size of 819,429.

RESULTS

The incidence of non-fatal burns was 166.3 per 100,000 per year. The rate was higher in females than in males (RR 1.15; 95% CI 1.03 to 1.27). Children less than 5 years of age were at much higher risk of burn injury than those older than 5 years (RR 7.05; 95% CI 6.35 to 7.8). Rural people were at more than three times higher risk of burn. The average number of days absent from school due to burn injury was 21.64 (SD 19.64); the average number of workdays lost was 22.96 (SD 35.94). The average duration of assistance required in daily living activities was 17.26 (SD 20.34) days. The hospitalisation rate was 12.6 per 100,000 population per year. The mean duration of hospital stay was 15.88 (SD 20.47) days. The rate of permanent disability was 2.6 per 100,000 population-years.

CONCLUSION

Burn is a major cause of morbidity, disability, school absence, and workday loss. Young children, females, and rural dwellers are at highest risk. Home is the most risky place for children and females in terms of burn injury risk. To halt this devastating health issue, a national strategy and programme for burn prevention must be developed.

Health seeking behaviour of parents of burned children in Bangladesh is related to family socioeconomics

OBJECTIVE

The study was design to explore the health seeking behaviour of Bangladeshi parents for their children during burn injuries.

METHODS

A population-based cross-sectional survey was conducted between January and December 2003 in Bangladesh. Nationally representative data were collected from 171,366 rural and urban households comprising of a total population of 819,429, including 351,651 children of 0-18 years. Mothers or heads of households were interviewed with a structured questionnaire in obtaining the information.

RESULTS

About sixty percent parents seek health care from unqualified service providers for their children during a childhood burn injury. Educated and the higher income groups parents choose qualified service provider at significantly higher rate compared to illiterate and poor. Higher proportion of parents of urban residence chooses qualified service provider compared to rural. No significant difference of health seeking behaviour of parent in choosing care provider was found in relation to sex of the children.

CONCLUSION

Education, economic condition and place of residence were found as the contributory factors in choosing service provider. Education to the parents can contribute in changes in health seeking behaviour which ultimately contribute in reducing morbidity and mortality from childhood burn injuries. Including parent's education a national burn prevention program needs to be developed to combat the devastating child injury, burn.

Pitfalls of formalin fixation for determination of antineutrophil cytoplasmic antibodies

Sera can produce nuclear or perinuclear immunofluorescence staining in neutrophils which may be caused by antibodies with differing antigenic specificities. These include perinuclear antineutrophil cytoplasmic antibodies (P-ANCA), granulocyte specific antinuclear antibody (GS-ANA), and antinuclear antibody (ANA). There is controversy over the value of formalin fixation of neutrophils in differentiating antibodies giving selective or preferential reaction with the nuclear or perinuclear area of neutrophils. In a comparative study of 77 sera, formalin fixation caused inconsistency, nonspecific effects, and false positivity owing to enhanced fluorescence. If formalin fixed neutrophils are used in the routine diagnostic laboratory, this will add confusion to the interpretation of the ANCA assay.

Efficacy of adhesion barriers. Resorbable hydrogel, oxidized regenerated cellulose and hyaluronic acid

OBJECTIVE

To compare a novel resorbable hydrogel barrier with two previously studied barriers, oxidized regenerated cellulose and hyaluronic acid, for the prevention of postoperative adhesions.

STUDY DESIGN

Two models were employed in the rat uterine horn, one of adhesion formation after devascularization and serosal injury and one of adhesion reformation after adhesiolysis

RESULTS

In the devascularization model, hydrogel treatment reduced the mean extent of adhesion formation from 73% in the control group to 13% (P < .005). Hyaluronic acid pretreatment reduced the extent of adhesion formation to 44% (P < .05), while oxidized regenerated cellulose failed to reduce formation (P > .25). In the adhesiolysis model, treatment with the hydrogel reduced the mean extent of adhesion formation from 87% in the control group to 20% (P < .005). Neither the oxidized regenerated cellulose nor the hyaluronic acid treatments lowered the extent of adhesion formation from the control group (P > .25). The hydrogel barrier was observed to be resorbed over a five-day period and remained adherent to the tissue during resorption.

CONCLUSION

Resorbable hydrogel barriers are highly effective in the reduction of adhesion formation and reformation in the rat. This probably due to the good biocompatibility and retention of these materials upon the site of application.

Adhesion prevention with ancrod released via a tissue-adherent hydrogel

The objective of this investigation was to evaluate the effect of ancrod, a fibrinogenolytic protease from Malayan pit viper venom, locally delivered through a photopolymerized biodegradable hydrogel in preventing postoperative adhesions. The experimental model involved ischemic and serosal injury to the uterine horns of rats with measurement of adhesions 7 days after injury. Ancrod was delivered intravenously for 5 days preoperatively through 3 days postoperatively, intraperitoneally for 5 days preoperatively, intraperitoneally for 3 days postoperatively, and locally via the hydrogel formed upon the uterine horns by photopolymerization of an aqueous precursor solution. Systemic defibrinogenation by intravenous administration pre-through postoperatively reduced the extent of adhesions by 63% without dose sensitivity from 5 to 20 units/kg/day. Preoperative defibrinogenation by intraperitoneal administration reduced adhesion extent by up to 57%, while postoperative administration was more effective, reducing adhesions by up to 84% with a dose-dependent response from 5 to 20 units/kg/day. Administration of ancrod by local release from a tissue-adherent hydrogel was more effective than either the hydrogel alone or the same amount of ancrod administered by postoperative intraperitoneal injection. Adhesions were reduced by 82% at a local dose of 10 units/kg, compared to a reduction of 68% due to the barrier properties of the gel alone (P < 0.01) and of 19% due to the same amount of drug given at the time of surgery (P < 0.001). Local delivery of ancrod from a tissue-adherent hydrogel barrier thus provided an efficacious prevention to postoperative adhesions while permitting administration of a low total dose of the protease.

Efficacy of a resorbable hydrogel barrier, oxidized regenerated cellulose, and hyaluronic acid in the prevention of ovarian adhesions in a rabbit model

OBJECTIVE

To compare the efficacy of a resorbable hydrogel material with oxidized regenerated cellulose and hyaluronic acid in an ovarian adhesion model.

DESIGN

Controlled, blinded, and randomized study involving female rabbits.

SETTING

Academic research environment.

INTERVENTIONS

A water-soluble hydrogen precursor was applied to the ovary as a liquid and converted to a hydrogel by exposure to long wavelength ultraviolet light, a 0.4% solution of hyaluronic acid was applied to the ovary, or an oxidized regenerated cellulose patch was applied to the ovary after wedge resectioning.

MAIN OUTCOME MEASURES

Extent and severity of adhesion formation.

RESULTS

Application of the hydrogel reduced adhesion formation by 88%. Neither oxidized regenerated cellulose nor hyaluronic acid reduced adhesion formation.

CONCLUSION

The photopolymerized, resorbable hydrogel material is highly effective for the reduction of periovarian adhesions in this model.

Inhibition of thrombosis and intimal thickening by in situ photopolymerization of thin hydrogel barriers

Thin hydrogel barriers formed on the inner surface of injured arteries by interfacial photopolymerization dramatically reduced thrombosis and intimal thickening in rat and rabbit models of vascular injury. This polymerization technique allowed the synthesis of a thin hydrogel barrier that conformed to the vessel wall, directly blocking contact between blood and the damaged vessel. The illumination conditions could be varied to control the thickness of the barrier from 10 microns to > 50 microns. The hydrogel was designed to degrade by nonenzymatic hydrolysis. In rats in which the carotid artery had been severely injured by crushing, treatment with the hydrogel barrier completely eliminated thrombosis (P < 0.01) and preserved long-term patency (P < 0.01). Treatment in a rabbit model of balloon injury inhibited thrombosis (P < 0.02) and reduced long-term intimal thickening by approximately 80% (P < 0.003). These results suggest that blood-borne signals acting in the early phases of healing play an important role in stimulating thickening of the intima.

Prevention of postoperative adhesions in the rat by in situ photopolymerization of bioresorbable hydrogel barriers

OBJECTIVE

To assess the efficacy of a novel resorbable hydrogel barrier for preventing postoperative adhesions in animals.

METHODS

A hydrogel barrier was formed in situ by photopolymerizing a solution of a macromolecular prepolymer in buffered saline using long-wavelength ultraviolet light. Two models in the rat were evaluated. In a primary adhesion model, devascularization and serosal injury were performed on the uterine horns using bipolar electrocautery. The prepolymer solution was applied to the horns and illuminated to form the barrier. On the seventh postoperative day, the fraction of the length of the horns involved in adhesions was scored, as was the quality of the adhesions. In a readhesion model, adhesions were formed as described and were surgically lysed on the seventh day, then were treated subsequently with the barrier and scored after 7 additional days. Each group in both models consisted of seven animals per treatment condition. Four prepolymer concentrations were examined in the primary adhesion model, and the optimal one was examined in the readhesion model.

RESULTS

A conformal hydrogel barrier coating was formed upon in situ photopolymerization and adhered to the treated tissues. No residual hydrogel barrier was observed 7 days after application of the optimal gel concentrations. In the primary adhesion model, the mean fraction of the horns involved in adhesions was reduced significantly, from 76% in controls to 10% (P < .0001), and treatment with a 10% solution of prepolymer was determined to be optimal (P = .025). In the readhesion model, surgical lysis of adhesions alone did not reduce adhesions significantly (from 86% to 79%; P = .3), whereas lysis with barrier treatment did (79% to 28%; P = .002).

CONCLUSIONS

In situ photopolymerization allowed the formation of adherent, conformal barriers, which demonstrated high efficacy in the prevention of adhesion formation and reformation in animals. This efficacy and ease of use warrant clinical evaluation.