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1.
Oncologist ; 29(1): 47-56, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-37390616

RESUMO

BACKGROUND: Combination chemotherapy and immunotherapy regimens have significantly improved survival for patients with previously untreated advanced non-small cell lung cancer (NSCLC). Improvements in overall survival (OS) in two separate pembrolizumab trials have demonstrated survival improvements over chemotherapy alone, regardless of PD-L1 status. The optimal chemotherapy backbone for combination with immunotherapy is unknown. We hypothesized nab-paclitaxel may be a well-suited platinum partner to use in combination with checkpoint inhibitor therapy for both adenocarcinoma and squamous histology and conducted a phase I/II trial to assess the efficacy of this regimen in advanced NSCLC. METHODS: Adult patients with previously untreated, stage IIIB/IV NSCLC (any histology) with an Eastern Cooperative Oncology Group performance status of 0-1, any PD-L1 expression, and no EGFR mutations or ALK translocations, received carboplatin area under the curve (AUC) 6 day 1, nab-paclitaxel 100 mg/m2 days 1, 8, 15, and pembrolizumab 200 mg day 1 q21 days for 4 cycles followed by maintenance pembrolizumab q3w. Co-primary endpoints were progression-free survival (PFS) and overall response rate (ORR). RESULTS: Forty-six evaluable patients enrolled, 14 in phase I and 32 in phase II, from June 2015 to July 2018 with a median duration of follow-up of 35.4 months. Median time from enrollment to data lock was 42 months. In the ITT population, the ORR was 35%, median PFS was 5.6 months (95% CI, 4.6-8.2), and median OS was 15.4 months (CI, 12.4-28.1). There were no statistical differences in PFS or OS by PD-L1 status. The 2- and 3-year landmark OS rates were 33% and 24%, respectively. CONCLUSION: Carboplatin, nab-paclitaxel, and pembrolizumab are a safe and effective regimen for patients with both squamous and nonsquamous NSCLC. Although this study did not meet the prespecified endpoints, the median and landmark OS results are consistent with durable benefit of this regimen as seen in phase III trials for first-line treatment of advanced NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Carcinoma de Células Escamosas , Neoplasias Pulmonares , Adulto , Humanos , Carcinoma Pulmonar de Células não Pequenas/patologia , Carboplatina/farmacologia , Carboplatina/uso terapêutico , Antígeno B7-H1 , Neoplasias Pulmonares/patologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Paclitaxel , Carcinoma de Células Escamosas/tratamento farmacológico
2.
Xenotransplantation ; 29(3): e12747, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35384085

RESUMO

Although human islet transplantation has proven to provide clinical benefits, especially the near complete amelioration of hypoglycemia, the supply of human islets is limited and insufficient to meet the needs of all people that could benefit from islet transplantation. Porcine islets, secreting insulin nearly identical to that of human insulin, have been proposed as a viable supply of unlimited islets. Further, encapsulation of the porcine islets has been shown to reduce or eliminate the use of immunosuppressive therapy that would be required to prevent rejection of the foreign islet tissue. The goal of the current study was to determine the long-term safety and efficacy of agarose encapsulated porcine islets (macrobeads) in diabetic cynomolgus macaques, in a study emulating a proposed IND trial in which daily exogenous insulin therapy would be reduced by 50% with no loss of glucose regulation. Four of six animals implanted with macrobeads demonstrated ≥ 30% reduction in insulin requirements in year 1 of follow-up. Animals were followed for 2, 3.5, and 7.4 years with no serious adverse events, mortality or evidence of pathogen transmission. This study supports the continued pursuit of encapsulated porcine islet therapy as a promising treatment option for diabetes mellitus.


Assuntos
Diabetes Mellitus Experimental , Transplante das Ilhotas Pancreáticas , Animais , Diabetes Mellitus Experimental/terapia , Humanos , Insulina/uso terapêutico , Macaca , Suínos , Transplante Heterólogo
3.
Oncologist ; 26(3): 224-230, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33098189

RESUMO

BACKGROUND: Thousands of patients annually receive treatment for advanced non-small cell lung cancer (NSCLC), but little is known about their views on the decision to receive that treatment, or regret. This trial prospectively evaluated the incidence of regret and whether baseline characteristics, patient decision-making parameters, or clinical progress early in the treatment course predicts regret. MATERIALS AND METHODS: Patients receiving systemic treatment for advanced NSCLC completed every 3-week patient reported outcome (PRO) assessment using the electronic Lung Cancer Symptom Scale (eLCSS-QL), including the 3-Item Global Index (3-IGI; assessing overall distress, activities, and quality of life [QL]). A prespecified secondary aim was to determine the frequency of regret evaluated at 3 months after starting treatment. Patients were randomized to usual care or enhanced care (which included use of the DecisionKEYS decision aid). RESULTS: Of 164 patients entered, 160 received treatment and 142 were evaluable for regret. In total, 11.5% of patients and 9% of their supporters expressed regret. Baseline characteristics did not predict regret; regret was rarely expressed by those who had a less than 20% decline or improvement in the 3-IGI PRO score after two treatment cycles. In contrast, when asked if they would make the same decision again, only 1% not having a 20% 3-IGI decline expressed regret, versus 14% with a 3-IGI decline (p = .01). CONCLUSION: The majority of patients having regret were identified early using the PRO 3-IGI of the eLCSS-QL measure. Identifying patients at risk for regret allows for interventions, including frank discussions of progress and goals early in the treatment course, which could address regret in patients and their supporters. IMPLICATIONS FOR PRACTICE: This report documents prospectively, for the first time, the incidence of treatment-related regret in patients with advanced lung cancer and outlines that risk of regret is associated with patient-determined worsening health status early in the course of treatment. Identifying patients at risk for regret early in treatment (before the third cycle of treatment) appears to be crucial. Counseling at that time should include a discussion of consideration of treatment change and the reason for this change.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Tomada de Decisões , Emoções , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Estudos Prospectivos , Qualidade de Vida
4.
J Neurooncol ; 149(2): 357-366, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32902767

RESUMO

PURPOSE/OBJECTIVE(S): Tyrosine kinase inhibitors (TKIs) are commonly employed for patients with brain metastases from lung cancer and specific driver mutations. We sought to identify the correlation between intracranial tumor burden and outcomes in patients with brain metastases treated with TKIs. MATERIALS/METHODS: We identified and retrospectively reviewed cases of EGFR-mutant or ALK-rearranged lung cancer with brain metastases at any time during their cancer course. Clinical characteristics and treatment information were abstracted from the medical records. Brain metastases were contoured to calculate total volume of disease at diagnosis and after initial therapy. High intracranial burden was defined as either > 10 brain metastases, volume of brain metastases > 15 cc, or largest lesion > 3 cm. Intracranial response was determined according to Response Assessment in Neuro-Oncology (RANO) criteria on the patient level. We determined the correlation between clinical and imaging characteristics and intracranial progression free survival (IC-PFS) and overall survival (OS). RESULTS: Fifty-seven patients with EGFR (n = 49) and ALK (n = 8) alterations were identified. Median follow-up from initial brain metastasis diagnosis was 17 months. Neurological symptoms were present in 54% at brain metastasis diagnosis. For those receiving TKIs alone or TKIs with radiation, at least a partial intracranial response (≥ 65% volume reduction) at 3 months from starting therapy was achieved in 94% and 58%. Progressive intracranial disease at 3 months occurred in 6.3% and 8.3%. Patients with high intracranial burden (n = 21) had a median 17 brain metastases, 6.5 cc volume, and 1.9 cm maximal tumor diameter. Median IC-PFS and OS for patients with high intracranial burden was 13.9 and 35.4 months. Patients with high intracranial burden and neurological symptoms at diagnosis had similar IC-PFS and OS compared to those with low burden and absence of neurological symptoms (p > 0.05 for each). CONCLUSION: Most patients receiving TKIs as part of their initial therapy achieve an early and durable volumetric intracranial response, irrespective of presenting disease burden or neurologic symptoms.


Assuntos
Quinase do Linfoma Anaplásico/genética , Neoplasias Encefálicas/terapia , Carcinoma Pulmonar de Células não Pequenas/terapia , Rearranjo Gênico , Mutação , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/secundário , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Terapia Combinada , Irradiação Craniana/mortalidade , Receptores ErbB/genética , Feminino , Seguimentos , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/terapia , Masculino , Pessoa de Meia-Idade , Prognóstico , Inibidores de Proteínas Quinases/uso terapêutico , Estudos Retrospectivos , Taxa de Sobrevida
5.
Chin J Cancer Res ; 30(1): 72-83, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29545721

RESUMO

OBJECTIVE: The complexity, heterogeneity and capacity of malignant neoplastic cells and tumors for rapid change and evolution suggest that living-cell-based biological-systems approaches to cancer treatment are merited. Testing this hypothesis, the tumor marker, metabolic activity, and overall survival (OS) responses, to the use of one such system, implantable macrobeads [RENCA macrobeads (RMBs)], in phase I and IIa clinical trials in advanced, treatment-resistant metastatic colorectal cancer (mCRC) are described here. METHODS: Forty-eight mCRC patients (30 females; 18 males), who had failed all available, approved treatments, underwent RMB implantation (8 RMB/kg body weight) up to 4 times in phase I and phase IIa open-label trials. Physicals, labs [tumor and inflammation markers, lactate dehydrogenase (LDH)] and positron emission tomography-computed tomography (PET-CT) imaging to measure number/volume and metabolic activity of the tumors were performed pre- and 3-month-post-implantation to evaluate safety and initial efficacy (as defined by biological responses). PET-CT maximum standard uptake value (SUVmax) (baseline and d 90; SUVmax ≥2.5), LDH, and carcinoembryonic antigen (CEA) and/or cancer antigen 19-9 (CA 19-9) response (baseline, d 30 and/or d 60) were assessed and compared to OS. RESULTS: Responses after implantation were characterized by an at least 20% decrease in CEA and/or CA 19-9 in 75% of patients. Fluorodeoxyglucose (FDG)-positive lesions (phase I, 39; 2a, 82) were detected in 37/48 evaluable patients, with 35% stable volume and stable or decreased SUV (10) plus four with necrosis; 10, increased tumor volume, SUV. LDH levels remained stable and low in Responders (R) (d 0-60, 290.4-333.9), but increased steadily in Non-responders (NR) (d 0-60, 382.8-1,278.5) (d 60, P=0.050). Responders to RMBs, indicated by the changes in the above markers, correlated with OS (R mean OS=10.76 months; NR mean OS=4.9 months; P=0.0006). CONCLUSIONS: The correlations of the tumor marker, tumor volume and SUV changes on PET-CT, and LDH levels themselves, and with OS, support the concept of a biological response to RMB implantation and the validity of the biological-systems approach to mCRC. A phase III clinical trial is planned.

6.
Xenotransplantation ; 23(6): 444-463, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27862363

RESUMO

BACKGROUND: The use of porcine islets to replace insulin-producing islet ß-cells, destroyed during the diabetogenic disease process, presents distinct challenges if this option is to become a therapeutic reality for the treatment of type 1 diabetes. These challenges include a thorough evaluation of the microbiological safety of the islets. In this study, we describe a robust porcine islet-screening program that provides a high level of confidence in the microbiological safety of porcine islets suitable for clinical trials. METHODS: A four-checkpoint program systematically screens the donor herd (Large White - Yorkshire × Landrace F1 hybrid animals), individual sentinel and pancreas donor animals and, critically, the islet macrobeads themselves. Molecular assays screen for more than 30 known viruses, while electron microscopy and in vitro studies are employed to screen for potential new or divergent (emergent) viruses. RESULTS: Of 1207 monthly samples taken from random animals over a 2-year period, only a single positive result for Transmissible gastroenteritis virus was observed, demonstrating the high level of biosecurity maintained in the source herd. Given the lack of clinical signs, positive antibody titers for Porcine reproductive and respiratory syndrome virus, Porcine parvovirus, and Influenza A confirm the efficacy of the herd vaccination program. Porcine respiratory coronavirus was found to be present in the herd, as expected for domestic swine. Tissue homogenate samples from six sentinel and 11 donor animals, over the same 2-year period, were negative for the presence of viruses when co-cultured with six different cell lines from four species. The absence of adventitious viruses in separate islet macrobead preparations produced from 12 individual pancreas donor animals was confirmed using validated molecular (n = 32 viruses), in vitro culture (cells from four species), and transmission electron microscopy assays (200 cell profiles per donor animal) over the same 2-year period. There has been no evidence of viral transmission following the implantation of these same encapsulated and functional porcine islets into non-immunosuppressed diabetic cynomolgus macaques for up to 4 years. Isolated peripheral blood mononuclear cells from all time points were negative for PCV (Type 2), PLHV, PRRSV, PCMV, and PERV-A, PERV-B, and PERV-C by PCR analysis in all six recipient animals. CONCLUSION: The four-checkpoint program is a robust and reliable method for characterization of the microbiological safety of encapsulated porcine islets intended for clinical trials.


Assuntos
Leucócitos Mononucleares/citologia , Pâncreas/microbiologia , Transplante Heterólogo , Animais , Linhagem Celular , Diabetes Mellitus Tipo 1/terapia , Insulina/metabolismo , Secreção de Insulina , Pâncreas/metabolismo , Transplante de Pâncreas , Sefarose/farmacologia , Suínos , Transplante Heterólogo/métodos
7.
Cancer Control ; 21(3): 221-30, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24955706

RESUMO

BACKGROUND: Mutations in BRAF were first reported in 2002. Since that time, the molecular basis for oncogenic signaling has been elucidated in multiple malignancies. The development of v-raf murine sarcoma viral oncogene homolog B (BRAF) inhibitors has helped improve clinical outcomes in malignant melanoma and is suggested by case reports in other malignancies. METHODS: A review of pertinent articles examining the mechanisms of BRAF signaling in various cancer types and an update on clinical trials of BRAF inhibitions are presented. RESULTS: Clinical response to BRAF inhibition varies by malignancy. In melanoma, single-agent vemurafenib or dabrafenib prolongs overall survival compared with chemotherapy, but both are limited by the development of acquired resistance in many patients. Results of early-phase clinical trials and case reports demonstrate responses in V600E-mutant non-small-cell lung cancer, thyroid cancer, and hairy cell leukemia. However, no significant difference in progression-free survival was seen in colorectal cancer with single-agent vemurafenib. Overcoming resistance to BRAF inhibition with combination therapy is an active area of research. CONCLUSIONS: The detection of BRAF mutations represents an advance in delivering molecularly targeted therapies to patients with a variety of cancers. Acquired resistance limits the ability of BRAF inhibitors to produce long-term remissions; however, combining BRAF inhibitors with the mitogen-activated protein kinase pathway and/or other pathway inhibitors represents a promising method to improve long-term outcomes.


Assuntos
Mutação , Neoplasias/enzimologia , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Animais , Humanos , Neoplasias/epidemiologia , Neoplasias/genética , Neoplasias/terapia , Transdução de Sinais
8.
Cancer Control ; 20(1): 22-31, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23302904

RESUMO

BACKGROUND: Lung cancer is the most common cause of cancer-related death in the United States, yet traditional chemotherapy fails to provide long-term benefit for many patients. New approaches are needed to improve overall survival beyond the current standard of care. METHODS: This review discusses recent clinical trials using immunotherapy techniques to treat both non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) and highlights ongoing immunotherapy research efforts at our center. RESULTS: For NSCLC, phase II clinical trials have examined allogeneic vaccines that target either mucin 1 (MUC1), epidermal growth factor or melanoma-associated antigen 3. These vaccines are now undergoing larger phase III trials. An autologous cellular therapy directed against transforming growth factor beta-2 and a recombinant protein with antitumor properties have also shown promise in prolonging survival in NSCLC in phase II trials. The monoclonal antibodies ipilimumab, BMS-936558 (anti-PD-1), and BMS936559 (anti-PD-L1) lead to enhanced T-cell-mediated antitumor effects and have produced objective responses in early-phase clinical trials. Studies for SCLC also exist, such as a novel vaccine therapy targeting p53. CONCLUSIONS: Recent clinical trials in lung cancer demonstrate the potential of immunotherapeutics to increase overall survival in patients with lung cancer compared with the current standard of care.


Assuntos
Vacinas Anticâncer/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/terapia , Imunoterapia/métodos , Neoplasias Pulmonares/terapia , Anticorpos Monoclonais/uso terapêutico , Antígenos de Neoplasias/imunologia , Carcinoma Pulmonar de Células não Pequenas/imunologia , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Ensaios Clínicos como Assunto , Fator de Crescimento Epidérmico/imunologia , Humanos , Ipilimumab , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/mortalidade , Mucina-1/imunologia , Proteínas de Neoplasias/imunologia , Nivolumabe , Carcinoma de Pequenas Células do Pulmão/imunologia , Carcinoma de Pequenas Células do Pulmão/mortalidade , Carcinoma de Pequenas Células do Pulmão/terapia , Fator de Crescimento Transformador beta2/imunologia
9.
Clin Liver Dis (Hoboken) ; 20(3): 93-96, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36187369

RESUMO

Content available: Audio Recording.

10.
Front Oncol ; 12: 986236, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36212442

RESUMO

Background: Frailty, sarcopenia and malnutrition are powerful predictors of clinical outcomes that are not routinely measured in patients with non-small cell lung cancer (NSCLC). The primary aim of this study was to investigate the association of sarcopenia, determined by the psoas muscle index (PMI) with overall survival (OS) in patients with advanced NSCLC treated with concurrent immune checkpoint inhibitor (ICI) and chemotherapy (CTX). Methods: We retrospectively reviewed data from a cohort of patients with locally advanced or metastatic NSCLC who were treated between 2015 and 2021 at the University of Virginia Medical Center. The cross-sectional area of the psoas muscle was assessed on CT or PET/CT imaging prior to treatment initiation. Multivariate analysis was performed using Cox proportional hazards regression models. Results: A total of 92 patients (median age: 64 years, range 36-89 years), 48 (52.2%) men and 44 (47.8%) women, were included in the study. The median follow-up was 29.6 months. The median OS was 17.8 months. Sarcopenia, defined by a PMI below the 25th percentile, was associated with significantly lower OS (9.1 months in sarcopenic patients vs. 22.3 months in non-sarcopenic patients, P = 0.002). Multivariate analysis revealed that sarcopenia (HR 2.12, P = 0.0209), ECOG ≥ 2 (HR 2.88, P = 0.0027), prognostic nutritional index (HR 3.02, P = 0.0034) and the absence of immune related adverse events (HR 2.04, P = 0.0185) were independently associated with inferior OS. Conclusions: Sarcopenia is independently associated with poor OS in patients with advanced NSCLC undergoing concurrent ICI and CTX.

11.
Biomolecules ; 12(11)2022 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-36358918

RESUMO

In the past decade, defective DNA repair has been increasingly linked with cancer progression. Human tumors with markers of defective DNA repair and increased replication stress exhibit genomic instability and poor survival rates across tumor types. Seminal studies have demonstrated that genomic instability develops following inactivation of BRCA1, BRCA2, or BRCA-related genes. However, it is recognized that many tumors exhibit genomic instability but lack BRCA inactivation. We sought to identify a pan-cancer mechanism that underpins genomic instability and cancer progression in BRCA-wildtype tumors. Methods: Using multi-omics data from two independent consortia, we analyzed data from dozens of tumor types to identify patient cohorts characterized by poor outcomes, genomic instability, and wildtype BRCA genes. We developed several novel metrics to identify the genetic underpinnings of genomic instability in tumors with wildtype BRCA. Associated clinical data was mined to analyze patient responses to standard of care therapies and potential differences in metastatic dissemination. Results: Systematic analysis of the DNA repair landscape revealed that defective single-strand break repair, translesion synthesis, and non-homologous end-joining effectors drive genomic instability in tumors with wildtype BRCA and BRCA-related genes. Importantly, we find that loss of these effectors promotes replication stress, therapy resistance, and increased primary carcinoma to brain metastasis. Conclusions: Our results have defined a new pan-cancer class of tumors characterized by replicative instability (RIN). RIN is defined by the accumulation of intra-chromosomal, gene-level gain and loss events at replication stress sensitive (RSS) genome sites. We find that RIN accelerates cancer progression by driving copy number alterations and transcriptional program rewiring that promote tumor evolution. Clinically, we find that RIN drives therapy resistance and distant metastases across multiple tumor types.


Assuntos
Instabilidade Genômica , Neoplasias , Humanos , Reparo do DNA/genética , Reparo do DNA por Junção de Extremidades , Neoplasias/genética , Replicação do DNA , Aberrações Cromossômicas
12.
Clin Case Rep ; 9(6): e04227, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34188921

RESUMO

Immunotherapy is an expanding area of cancer treatment with significant promise. Despite their efficacy, checkpoint inhibitors are associated with a number of immune-related adverse events; here, we described thrombocytopenia secondary todurvalumab.

13.
Front Oncol ; 10: 585551, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33489883

RESUMO

It has long been recognized that defects in cell cycle checkpoint and DNA repair pathways give rise to genomic instability, tumor heterogeneity, and metastasis. Despite this knowledge, the transcription factor-mediated gene expression programs that enable survival and proliferation in the face of enormous replication stress and DNA damage have remained elusive. Using robust omics data from two independent studies, we provide evidence that a large cohort of lung adenocarcinomas exhibit significant genome instability and overexpress the DNA damage responsive transcription factor MYB proto-oncogene like 2 (MYBL2). Across two studies, elevated MYBL2 expression was a robust marker of poor overall survival and disease-free survival outcomes, regardless of disease stage. Clinically, elevated MYBL2 expression identified patients with aggressive early onset disease, increased lymph node involvement, and increased incidence of distant metastases. Analysis of genomic sequencing data demonstrated that MYBL2 High lung adenocarcinomas had elevated somatic mutation burden, widespread chromosomal alterations, and alterations in single-strand DNA break repair pathways. In this study, we provide evidence that impaired single-strand break repair, combined with a loss of cell cycle regulators TP53 and RB1, give rise to MYBL2-mediated transcriptional programs. Omics data supports a model wherein tumors with significant genomic instability upregulate MYBL2 to drive genes that control replication stress responses, promote error-prone DNA repair, and antagonize faithful homologous recombination repair. Our study supports the use of checkpoint kinase 1 (CHK1) pharmacological inhibitors, in targeted MYBL2 High patient cohorts, as a future therapy to improve lung adenocarcinoma patient outcomes.

14.
Cell Transplant ; 17(5): 567-75, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18714676

RESUMO

Islet xenografts from porcine donors can reverse diabetes in experimental animal models and may be an alternative to human islet transplantation. We have recently reported the ability of porcine islets encapsulated in a double layer of hydrophilic agarose to maintain in vitro functional ability for >6 months. Although beta-cells are capable of adapting their secretory capacity in response to glucose levels, evidence has shown that prolonged hyperglycemia can compromise this ability. The aim of the present study was to determine the effects of diet manipulation on the long-term regulation of blood glucose levels, and the preservation of functional islet in the macrobeads. Twenty-one streptozotocin-induced diabetic Wistar-Furth male rats were randomly assigned to two diets containing 64% carbohydrate (CHO) or 20% CHO. Groups of five to six animals assigned to either diet were implanted with either empty (EM) or porcine islet-containing macrobeads (PIM) and followed for 333 days. Observations included general condition, body weight, blood glucose, and food and water intakes. Monthly blood samples were collected for insulin and C-peptide analysis. The 20% CHO diet significantly lowered blood glucose values when compared with those of the 64% CHO groups for both the empty (14.94 +/- 0.41 vs. 16.26 +/- 0.42 mmol/L, respectively, p < 0.001) and islet macrobead recipients (12.88 +/- 0.39 vs. 15.57 +/-0.85 mmol/L, respectively, p <0.001). The different diets, however, had no statistically significant effects on the preservation of islet mass in the macrobead. Serum porcine C-peptide was detected throughout the experiment in animals receiving porcine islet macrobeads, regardless of diet. Diabetic rats fed a low carbohydrate level diet and transplanted with porcine islet macrobeads had improved total tissue glucose disposal and improved clinical parameters associated with diabetes.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Experimental/dietoterapia , Diabetes Mellitus Experimental/cirurgia , Dieta com Restrição de Carboidratos , Transplante das Ilhotas Pancreáticas , Animais , Cápsulas , Diabetes Mellitus/dietoterapia , Diabetes Mellitus/metabolismo , Diabetes Mellitus/cirurgia , Diabetes Mellitus Experimental/metabolismo , Teste de Tolerância a Glucose , Humanos , Insulina/sangue , Masculino , Ratos , Ratos Endogâmicos BB , Ratos Endogâmicos WF , Sefarose , Suínos , Transplante Heterólogo
16.
Cell Transplant ; 16(6): 609-20, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17912952

RESUMO

The ability to culture porcine islets for extended times allows for both their functional assessment and the assurance of their microbiological safety prior to transplantation. We have previously shown that agarose-encapsulated porcine islets can be cultured for at least 24 weeks. In the current study, porcine islet agarose macrobeads cultured for up to 67 weeks were assessed for their ability to restore normoglycemia, respond to an intraperitoneal glucose challenge, maintain spontaneously diabetic BB rats free of insulin therapy for more than 6 months, and for their biocompatibility. Porcine islets were encapsulated in agarose macrobeads and subjected to weekly static perifusion assays for the assessment of insulin production. After in vitro culture for either 9, 40, or 67 weeks, 56-60 macrobeads were transplanted to each spontaneously diabetic BB rat. Transplanted rats were monitored daily for blood glucose levels. Glucose tolerance tests and assessments for porcine C-peptide were conducted at various intervals throughout the study. Normoglycemia (100-200 mg/dl) was initially restored in all islet transplanted rats. Moderate hyperglycemia (200-400 mg/dl) developed at around 30 days posttransplantation and continued throughout the study period of 201-202 days. Importantly, all rats that received encapsulated porcine islets continued to gain weight and were free of exogenous insulin therapy for the entire study. Porcine C-peptide (0.2-0.9 ng/ml) was detected in the serum of islet recipients throughout the study period. No differences were detected between recipient animals receiving islet macrobeads of various ages. These results demonstrate that the encapsulation of porcine islets in agarose macrobeads allows for extended culture periods and is an appropriate strategy for functional and microbiological assessment prior to clinical use.


Assuntos
Glicemia/análise , Diabetes Mellitus Tipo 1/cirurgia , Transplante das Ilhotas Pancreáticas/métodos , Animais , Materiais Biocompatíveis , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/cirurgia , Diabetes Mellitus Tipo 1/sangue , Estudos de Viabilidade , Sobrevivência de Enxerto , Insulina/metabolismo , Secreção de Insulina , Masculino , Microesferas , Ratos , Ratos Endogâmicos BB , Ratos Wistar , Sefarose , Suínos , Transplante Heterólogo , Resultado do Tratamento
17.
Interface Focus ; 6(4): 20160018, 2016 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-27499844

RESUMO

Many countries have a rapidly ageing population, placing strain on health services and creating a growing market for assistive technology for older people. We have, through a student-led, 12-week project for 10 students from a variety of science and engineering backgrounds, developed an integrated sensor system to enable older people, or those at risk, to live independently in their own homes for longer, while providing reassurance for their family and carers. We provide details on the design procedure and performance of our sensor system and the management and execution of a short-term, student-led research project. Detailed information on the design and use of our devices, including a door sensor, power monitor, fall detector, general in-house sensor unit and easy-to-use location-aware communications device, is given, with our open designs being contrasted with closed proprietary systems. A case study is presented for the use of our devices in a real-world context, along with a comparison with commercially available systems. We discuss how the system could lead to improvements in the quality of life of older users and increase the effectiveness of their associated care network. We reflect on how recent developments in open source technology and rapid prototyping increase the scope and potential for the development of powerful sensor systems and, finally, conclude with a student perspective on this team effort and highlight learning outcomes, arguing that open technologies will revolutionize the way in which technology will be deployed in academic research in the future.

18.
Cell Transplant ; 14(7): 427-39, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16285251

RESUMO

For clinical xenogenic islet transplantation to be successful, several requirements must be met. Among them is a sizeable and reliable source of fully functional and microbiologically safe islets. The inherent variability among porcine pancreases, with respect to islet yield, prompted us to develop a Biopsy Score technique to determine the suitability of each pancreas for islet isolation processing. The Biopsy Score consists of an assessment of five variables: warm ischemia time, pancreas color, fat content, islet size, and islet demarcation, each of which is assigned a value of -1 or +1, depending on whether or not the established criteria is met. For determination of islet size and demarcation, fresh biopsies of porcine pancreases are stained with dithizone (DTZ) solution and examined under a dissecting microscope. Based on the scoring of such biopsies in pancreases from 26-56-month-old sows, we report here that the presence of large (>100 microm diameter), well-demarcated islets in the pancreas biopsy is a reliable predictor of isolation success. Encapsulation of the isolated porcine islets within the inner layer of a 1.5% agarose and an outer layer of 5.0% agarose macrobead, containing 500 equivalent islet number (EIN), provides for extended in vitro functional viability (>6 months of insulin production in response to glucose), as well as for comprehensive microbiological testing and at least partial isolation of the xenogeneic islets from the host immune system. All microbiological testing to date has been negative, except for the presence of porcine endogenous retrovirus (PERV). Taken together, we believe that the Biopsy Score enhancement of our islet isolation technique and our agarose-agarose macroencapsulation methodology bring us significantly closer to realizing clinical porcine islet xenotransplantation for the treatment of insulin-dependent diabetic patients.


Assuntos
Transplante das Ilhotas Pancreáticas/normas , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/microbiologia , Pâncreas/citologia , Técnicas de Cultura de Tecidos/métodos , Animais , Cápsulas , Ilhotas Pancreáticas/química , Transplante das Ilhotas Pancreáticas/métodos , Masculino , Camundongos , Pâncreas/química , Pâncreas/patologia , Segurança , Suínos , Sobrevivência de Tecidos
19.
Transl Lung Cancer Res ; 4(5): 515-23, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26629420

RESUMO

In many cancers, including non-small cell lung cancer (NSCLC), tumor angiogenesis pathways have been identified as important therapeutic targets. Angiogenesis is essential in the process of primary tumor growth, proliferation and metastasis. One of the best characterized group of protein factors for angiogenesis include the members of the vascular endothelial growth factor (VEGF) family, consisting of VEGF-(A-D), and placenta growth factor (PIGF). Targeting tumor angiogenesis has been approached through two primary methods, monoclonal antibodies that block VEGF-vascular endothelial growth factor receptor (VEGFR) binding or small molecule tyrosine kinase inhibitors (TKIs) that inhibit the downstream VEGFR mediated signaling. Many TKIs inhibit multiple pro-angiogenic and pro-proliferative pathways such as the mitogen activated protein (MAP) kinase pathway. Bevacizumab and ramucirumab, monoclonal antibodies targeting VEGF and the VEGFR, respectively, have each led to improvements in overall survival (OS) for NSCLC when added to standard first and second line chemotherapy, respectively. Small incremental gains seen with both bevacizumab and ramucirumab may be further improved upon by incorporating novel agents and treatment strategies, and many additional trials are ongoing.

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