The Effect of Concurrent Stereotactic Body Radiation and Anti-PD-1 Therapy for Recurrent Metastatic Sarcoma.

Patients diagnosed with metastatic sarcoma have limited options for achieving both local and distant tumor control. While SBRT can achieve local control, distant response rates remain low. There is limited evidence demonstrating the safety and efficacy for combining SBRT with concurrent PD-1 checkpoint blockade in metastatic sarcoma. In this prospective case-series, we examined five patients with metastatic sarcoma on pembrolizumab treated concurrently with SBRT from July 1, 2016-October 30, 2018. Acute and chronic toxicity were recorded using Common Terminology Criteria for Adverse Events (CTCAE, version 5.0). SBRT-treated tumor control was assessed using Response Evaluation Criteria in Solid Tumors (RECIST version 1.1). With median follow-up of 14.9 months, three patients with undifferentiated pleomorphic sarcoma, one with intimal, and one with chondroblastic osteosarcoma received SBRT with concurrent pembrolizumab to 10 sites of metastatic disease. No grade 5 toxicities were observed. There was a single incidence of transient grade 4 lymphopenia which resolved without intervention. Grade 3 toxicities included anemia, thrombocytopenia, lymphopenia and colitis. One tumor demonstrated local progression after SBRT, and all others remained stable or with response. In conclusion, combining SBRT with PD-1 inhibition appeared to be safe in this patient population. Expected high rates of treated-tumor local control after SBRT were observed. Two of five patients demonstrated either enhanced local tumor regression, or possible abscopal effect.

Cutaneous malignant melanoma of the oral cavity following skin graft reconstruction: Case report.

BACKGROUND: Malignant melanomas on skin graft recipient sites are rare, with few cases reported in the literature. METHODS: We present a case report of a patient with recurrent cutaneous melanoma in the grafted anterolateral thigh flap of the tongue. RESULTS: A patient underwent hemiglossectomy with free flap reconstruction for squamous cell carcinoma of the tongue. Five years later the patient was seen with a 1-cm nodule and surrounding erythroplakia at the recipient site of the graft. Analysis revealed cutaneous malignant melanoma. Patient then related a remote history of a suspected skin melanoma of the donor leg that had been treated with excision, with unknown histology. CONCLUSION: This may be the first reported case of a cutaneous malignant melanoma in the oral cavity following an anterolateral thigh free flap reconstruction, emphasizing the importance of obtaining a comprehensive history of skin cancers and closely inspecting the donor site prior to graft harvesting.

A Novel Use of Aortic Stent Graft Components in Massive Venous Retroperitoneal Hematoma.

Venous retroperitoneal hematoma (VRH) can present as a sudden-onset life-threatening condition. Unlike arterial hematoma, VRH is difficult to treat because of anatomic and structural considerations. Moreover, because VRH is rare and iatrogenic, there are no commercially available devices to treat this problem. We present a novel use of aortic stent graft components to treat a large, life-threatening VRH.

Automated model-based quantitative analysis of phantoms with spherical inserts in FDG PET scans.

PURPOSE: Quality control plays an increasingly important role in quantitative PET imaging and is typically performed using phantoms. The purpose of this work was to develop and validate a fully automated analysis method for two common PET/CT quality assurance phantoms: the NEMA NU-2 IQ and SNMMI/CTN oncology phantom. The algorithm was designed to only utilize the PET scan to enable the analysis of phantoms with thin-walled inserts. METHODS: We introduce a model-based method for automated analysis of phantoms with spherical inserts. Models are first constructed for each type of phantom to be analyzed. A robust insert detection algorithm uses the model to locate all inserts inside the phantom. First, candidates for inserts are detected using a scale-space detection approach. Second, candidates are given an initial label using a score-based optimization algorithm. Third, a robust model fitting step aligns the phantom model to the initial labeling and fixes incorrect labels. Finally, the detected insert locations are refined and measurements are taken for each insert and several background regions. In addition, an approach for automated selection of NEMA and CTN phantom models is presented. The method was evaluated on a diverse set of 15 NEMA and 20 CTN phantom PET/CT scans. NEMA phantoms were filled with radioactive tracer solution at 9.7:1 activity ratio over background, and CTN phantoms were filled with 4:1 and 2:1 activity ratio over background. For quantitative evaluation, an independent reference standard was generated by two experts using PET/CT scans of the phantoms. In addition, the automated approach was compared against manual analysis, which represents the current clinical standard approach, of the PET phantom scans by four experts. RESULTS: The automated analysis method successfully detected and measured all inserts in all test phantom scans. It is a deterministic algorithm (zero variability), and the insert detection RMS error (i.e., bias) was 0.97, 1.12, and 1.48 mm for phantom activity ratios 9.7:1, 4:1, and 2:1, respectively. For all phantoms and at all contrast ratios, the average RMS error was found to be significantly lower for the proposed automated method compared to the manual analysis of the phantom scans. The uptake measurements produced by the automated method showed high correlation with the independent reference standard (R2 ≥ 0.9987). In addition, the average computing time for the automated method was 30.6 s and was found to be significantly lower (P ≪ 0.001) compared to manual analysis (mean: 247.8 s). CONCLUSIONS: The proposed automated approach was found to have less error when measured against the independent reference than the manual approach. It can be easily adapted to other phantoms with spherical inserts. In addition, it eliminates inter- and intraoperator variability in PET phantom analysis and is significantly more time efficient, and therefore, represents a promising approach to facilitate and simplify PET standardization and harmonization efforts.

Design of a compact collimator and 3D imaging system for a scanning beam low-energy intraoperative radiation therapy system for pancreatic cancer.

Intraoperative radiation therapy (IORT) involves delivering high doses of radiation directly to tumors while sparing healthy tissues in a surgical setting. Current IORT systems are limited in their lack of image guidance and variable needs for shielded operating rooms. They also lack the capability to deliver non-uniform therapeutic radiation to irregular shaped clinical targets. We developed a scanning beam IORT system (SBIORT) to overcome these limitations. SBIORT consists of a low energy x-ray source, a custom compact dynamic x-ray collimator system, a robotic arm, and a 3D surface imaging module. Here we describe the design and validation of the compact dynamic x-ray collimator system and the 3D surface imaging module for use in SBIORT. The proposed collimator can achieve a leaf position accuracy of ± 0.25 mm (95% confidence interval). Phantom studies indicated the 3D surface-imaging module has an accuracy of 1.0 ± 0.6 mm with ability to obtain high resolution surface image within 5 seconds. SBIORT is a novel approach to deliver conformal intensity-modulated intraoperative radiation therapy.

Activation of the CRABPII/RAR pathway by curcumin induces retinoic acid mediated apoptosis in retinoic acid resistant breast cancer cells.

Due to the anti-proliferative and anti-apoptotic effects of retinoic acid (RA), this hormone has emerged as a target for several diseases, including cancer. However, development of retinoid resistance is a critical issue and efforts to understand the retinoid signaling pathway may identify useful biomarkers for future clinical trials. Apoptotic responses of RA are exhibited through the cellular RA-binding protein II (CRABPII)/retinoic acid receptor (RAR) signaling cascade. Delivery of RA to RAR by CRABPII enhances the transcriptional activity of genes involved in cell death and cell cycle arrest. The purpose of this study was to investigate the role of curcumin in sensitizing RA-resistant triple-negative breast cancer (TNBC) cells to RA-mediated apoptosis. We provide evidence that curcumin upregulates the expression of CRABPII, RARß and RARγ in two different TNBC cell lines. Co-treatment of the cells with curcumin and RA results in increased apoptosis as demonstrated by elevated cleavage of poly(ADP-ribose) polymerase and cleaved caspase-9. Additionally, silencing CRABPII reverses curcumin sensitization of TNBC cells to the apoptotic inducing effects of RA. These findings provide mechanistic insights into sensitizing TNBC cells to RA-mediated cell death by curcumin-induced upregulation of the CRABPII/RAR pathway.

A Single-Institution Analysis of Thymic Carcinoma Treated with Multi-Modality Therapy.

PURPOSE: Review of our experience in treating thymic carcinoma patients using a combination of surgery, chemotherapy and radiation therapy. METHODS: An institutional review of thymic carcinoma patients treated between 2007 and 2014 was performed analyzing clinical characteristics, treatment intent, surgical margin status, and radiation treatment dose. Survival curves were generated using the Kaplan-Meier method. RESULTS: Nine individuals were treated for newly diagnosed thymic carcinoma. Three patients had unresectable disease at presentation; two of these were treated with definitive chemoradiation therapy while another received neoadjuvant chemotherapy. Seven subjects underwent surgical resection (one after neoadjuvant chemotherapy) with pathological staging ranging from IIa - IVb disease. Patients were planned for adjuvant radiotherapy followed by chemotherapy; however, one developed liver metastases prior to initiating radiotherapy and was therefore treated with palliative chemotherapy alone. A second patient was non-compliant with radiation treatments and was considered as treated with palliative chemotherapy alone. Of the seven patients who completed definitive treatment, median time to progression and overall survival has yet to be reached. Only one of these patients developed progressive disease 10 months after completing treatment and eventually succumbed to disease 41 months after completing definitive therapy. With a median follow up of 30 months, two year overall survival is 67% for all patients. CONCLUSION: Resection with an emphasis on best possible oncologic margins, followed by radiation and chemotherapy remains an effective treatment strategy for advanced stage thymic carcinoma. In patients who present with unresectable tumors, neoadjuvant chemotherapy or definitive chemoradiation therapy may also be considered as viable treatment strategies.

Induction of regulatory T-cells from memory T-cells is perturbed during acute exacerbation of multiple sclerosis.

Regulatory T-cells (Tregs) are vital for maintaining immunological self-tolerance, and the transcription factor FOXP3 is considered critical for their development and function. Peripheral Treg induction may significantly contribute to the total Treg pool in healthy adults, and this pathway may be enhanced in thymic-deficient conditions like multiple sclerosis (MS). Here, we evaluated iTreg formation from memory versus naïve CD4(+)CD25(-) T-cell precursors. We report the novel finding that memory T-cells readily expressed CD25 and FOXP3, and demonstrated significantly greater suppressive function. Additionally, the CD25(-)FOXP3(-) fraction of stimulated memory T-cells also displayed robust suppression not observed in naïve counterparts or ex vivo resting (CD25(-)) T-cells. This regulatory population was present in both healthy subjects and clinically-quiescent MS patients, but was specifically deficient during disease exacerbation. These studies indicate that iTreg development and function are precursor dependent. Furthermore, MS quiescence appears to correlate with restoration of suppressive function in memory-derived CD4(+)CD25(-)FOXP3(-) iTregs.

Recanalization of infrainguinal chronic total occlusions with the crosser system: results of the PATRIOT trial.

PURPOSE: To evaluate the angiographic and functional outcomes of the Crosser chronic total occlusion (CTO) recanalization system used to facilitate crossing of infrainguinal occlusions resistant to conventional guidewire techniques. METHODS: Eighty-five patients with a previous or concurrent failed attempt to cross a CTO using conventional guidewire techniques were enrolled at eight United States centers. Occlusions were at least 30 days old and ≤30 cm in length. Primary endpoints included advancement of the recanalization system into or through the occlusion gaining guidewire access in the distal vessel beyond the lesion, and 30-day freedom from clinical perforation requiring treatment. RESULTS: The average age of occlusion was 16 months, the mean occlusion length was 117.5 ± 84.0 mm, 55.7% had unfavorable morphology for crossing, and 75% were moderately to severely calcified. Superficial femoral artery (SFA) occlusions were most commonly treated (61.2%), followed by popliteal artery (20%), and tibioperoneal (16.5%) occlusions. The CTO was crossed and the guidewire successfully advanced into the distal true lumen in 83.5% of cases. Following adjunctive therapy, 81.2% achieved a satisfactory angiographic result (≤50% residual stenosis). At 30 days post procedure, 98.8% of patients were free from clinical perforation. CONCLUSION: Use of the Crosser CTO recanalization system facilitated crossing of guidewire-resistant, chronic, infrainguinal occlusions with minimal risk of clinically significant vessel perforation.

Implications of in situ thrombosis and distal embolization during superficial femoral artery endoluminal intervention.

BACKGROUND: Endoluminal therapy for superficial femoral artery (SFA) occlusive disease is commonplace, but the incidence and outcomes of in situ thrombosis (IST) and distal embolization (DE) have not been well defined. The aim of this study was to examine the impact of IST and DE on long-term outcomes of SFA interventions. METHODS: A database of patients undergoing endovascular treatment of the SFA was queried. Patients who developed either IST treated by pharmacomechanical lytic therapy or DE were selected and compared to those without either event (control). Kaplan-Meier survival analyses were performed to assess time-dependent outcomes, with 2-year outcomes reported. Factor analyses were performed using a Cox proportional hazard model for time-dependent variables. RESULTS: There were 818 limbs that underwent endovascular treatment for symptomatic SFA disease (59% for claudication and 41% rest pain and tissue loss). In the control group, 69% underwent angioplasty, 16% underwent primary stenting, and 15% underwent laser/directional atherectomy. In the IST group, these numbers were 41%, 28%, and 31%, respectively, while in the DE group they were 35%, 32%, and 33%, respectively. Overall the rates were 7.3% with 3.5% suffering IST (all treated with lytic therapy) and 3.8% suffering DE (68% treated percutaneously and the remainder treated by embolectomy). Females were more likely to experience either event. Compared to the control group, only one-third of the patients who suffered DE had primary angioplasty, while the remainder underwent primary stenting or laser/directional atherectomy. There was no difference in primary, assisted primary, or secondary patency rates between the control and DE groups. DE resulted in significantly lower limb salvage (87 + or - 2% vs. 68 + or - 8%, control vs. DE, p<0.05) and freedom from recurrent symptoms (73 + or - 2% vs. 69 + or - 8%, control vs. DE, p<0.05), while IST treated with lytic therapy was associated with lower patency (67 + or - 2% vs. 37 + or - 6% primary, 77 + or - 2% vs. 41 + or - 9% assisted primary, and 79 + or - 2% vs. 44 + or - 9%, secondary, control vs. IST, p<0.01). There was no difference in outcomes based on whether surgical or percutaneous therapy was used to treat DE. While preoperative tibial runoff did not influence limb loss after DE, it was significantly associated with decreased patency after IST. CONCLUSION: DE during SFA interventions is associated with limb loss independently of preoperative runoff and subsequent intervention while the use pharmacomechanical lytic therapy for IST is associated with loss of patency but equivalent limb salvage and freedom from recurrent symptoms.

Impact of runoff on superficial femoral artery endoluminal interventions for rest pain and tissue loss.

BACKGROUND: While aggressive endoluminal therapy for superficial femoral artery (SFA) occlusive disease is commonplace, the implications of runoff on long-term outcomes of these interventions in patients with rest pain and tissue loss is unclear. Runoff is known to negatively effect graft patency. The aim of this study is to examine the impact of distal runoff on long-term outcomes of SFA interventions for critical ischemia. METHODS: A prospective database of patients undergoing endovascular treatment of the SFA between 1986 and 2007 was queried. Patients with Rutherford symptom classification 4, 5, and 6 were selected. Patients with concomitant tibial interventions were excluded. Pre-operative angiograms were reviewed in all cases to assess distal popliteal and tibial runoff and were scored according to modified Society of Vascular Surgery criteria for both vessels such that a higher score implies worse runoff (minimum 1 and maximum 19). Three runoff score groups were identified: <5 (good), 5-10 (compromised), and >10 (poor). Kaplan-Meier survival analyses were performed to assess time-dependent outcomes. Multivariate and factor analyses were performed. RESULTS: Three hundred six limbs in 241 patients (57% male, mean age 68 years) underwent endovascular treatment for critical ischemia (44% rest pain and 56% tissue loss.) Technical success was 96% with 61% SFA undergoing angioplasty, 37% SFA primary stenting and 2% SFA an atherectomy. Overall mortality was 1% and overall morbidity was 16% at 90 days after the procedure. At 5 years, vessels with compromised and poor runoff had significantly worse cumulative patency (82 +/- 9%, 56 +/- 4%, and 52 +/- 7% for good, compromised, and poor runoffs, respectively, mean +/- standard error of the mean [SEM]). Freedom from recurrent symptoms (65 +/- 8%, 39 +/- 9%, and 18 +/- 9% for good, compromised, and poor runoffs, respectively) and limb salvage (65 +/- 5%, 41 +/- 4%, and 20 +/- 6% for Good, Compromised, and Poor runoffs, respectively) were incrementally curtailed by worsening runoff with significant decreases as runoff category deteriorated. CONCLUSIONS: In patients presenting with rest pain and tissue loss who are treated with SFA percutaneous interventions, patency is negatively affected by compromised and poor runoffs in keeping with the bypass literature. More importantly, freedom from recurrent symptoms and limb salvage are incrementally curtailed as runoff scores worsen. These findings are consistent with the bypass literature.

Implications of acute functional injury following percutaneous renal artery intervention.

Percutaneous renal artery revascularization for hypertension and renal dysfunction is now common, and there is an increasing realization that renal artery intervention can be associated with parenchymal injury. The frequency, cause, and outcomes of acute functional injury associated with renal intervention are poorly delineated. Our aim was to determine the frequency of acute functional renal injury 30 days after renal artery intervention, to identify factors associated with functional renal injury and determine whether functional renal injury related to renal intervention is associated with late adverse clinical events. A retrospective analysis of patients undergoing renal artery interventions for atherosclerotic renal artery disease between 1990 and 2007 was performed. No distal embolic protection devices were used. Acute functional parenchymal renal injury was defined as a persistent increase in serum creatinine of > or =0.5 mg/dL at 1 month after the procedure. Freedom from kidney-related morbidity (increase in persistent creatinine >20% of baseline, progression to hemodialysis, death from kidney-related causes) and patient survival were measured. There were 418 patients who underwent 581 renal artery interventions: 57% for hypertension, 23% for hypertension associated with chronic renal insufficiency, and 12% for renal insufficiency. Acute functional renal injury occurred in 20% of the patients. The occurrence of a functional injury was associated with a significant decrement in freedom from kidney-related morbidity (mean +/- SEM 80 +/- 2% vs. 55 +/- 10%, no injury vs. injury, p < 0.01) and markedly decreased survival at 5-year follow-up (71 +/- 4% vs. 41 +/- 10%, p < 0.01). At 5-year follow-up, three times as many patients with functional injury progressed to hemodialysis compared to those without injury (19% vs. 7%, p < 0.01). By multivariate analysis, the presence of an unrepaired abdominal aortic aneurysm (AAA), low estimated glomerular filtration rate, non-insulin-dependent diabetes mellitus, contralateral renal artery disease, and a solitary kidney were significantly associated with functional injury and poor long-term clinical benefit. Hypertension, hyperlipidemia, and contrast volume were determined to be not significant. Acute functional renal injury occurs in approximately 20% of patients undergoing percutaneous renal artery intervention and is more likely in the presence of an unrepaired AAA, non-insulin-dependent diabetes mellitus, and preexisting renal disease. Acute functional renal injury is a negative predictor of survival and is associated with subsequent renal failure, need for dialysis, and death. While this data set does not establish a causal relationship, patients who are predisposed to acute functional injury may have underlying factors that also lead to decreased long-term renal function and decreased survival.

The long-term outcomes of percutaneous therapy for renal artery fibromuscular dysplasia.

BACKGROUND: Percutaneous intervention for symptomatic renal artery fibromuscular dysplasia (FMD) has replaced surgical therapy as first-line treatment. This study evaluates the factors that impact long-term anatomic and functional outcomes of endovascular therapy for symptomatic renal artery FMD. METHODS: Records of patients who underwent renal artery angioplasty for FMD between January 1990 and December 2007 were retrospectively analyzed. Indication for intervention was poorly controlled hypertension (diastolic blood pressure >90 mm Hg or systolic blood pressure >140 mm Hg, or both, taking >2 antihypertensive medications). Twenty-nine women (average age, 45 years [range, 18-80]; 86% with a history of hypertension <8 years) underwent 38 attempted interventions. Sixty-six percent of contralateral kidneys were normal (31% had a 60% stenosis, and the remainder were nonfunctioning or absent. Creatinine was >1.5 mg/dL in 4%, 24% had hyperlipidemia, 17% had metabolic syndrome, and 4% were considered diabetic. OUTCOMES: All interventions were successfully performed. Stent placement was required in 13% for technical failure and flow-limiting dissection. Seventy-three percent of these lesions were in the proximal renal artery, with the remainder in the middle renal artery. Technical success (<30% residual stenosis) was achieved in all vessels. There were no periprocedural or 90-day deaths. The procedurally related complication rate was 8%. Median follow-up was 2 years. All patients were alive at follow-up. Primary and assisted primary patency rates were 66% and 87% at 5 years. Restenosis was considered a 50% reduction in luminal area on angiography during follow-up. The restenosis rate was 28% at 5 years (10 vessels underwent repeat percutaneous intervention). Immediate clinical benefit was seen in hypertension in 72% (improved or cured 9 cm, functional status of the contralateral kidney, a fasting blood glucose <110 mg/dL, triglycerides <150 mg/dL, and high-density lipoprotein >50 mg/dL. Neither age <50 years nor statin administration appeared significant. CONCLUSIONS: Percutaneous endovascular intervention for clinically symptomatic FMD in the renal arteries is technically successful, safe, and durable. Most patients have immediate clinical benefit, with continued long-term results out to 5 years. It appears that the presence of existing renal pathology and markers of prediabetic state are associated with recurrence of hypertensive symptoms.

Percutaneous superficial femoral artery interventions for claudication--does runoff matter?

Endoluminal therapy for superficial femoral artery (SFA) occlusive disease for claudication is commonplace, but the implications of tibial vessel runoff on long-term outcomes of these interventions in patients with claudication are unclear. Runoff is known to negatively affect graft patency, but no data are available on the impact of runoff on percutaneous SFA interventions and their implications during follow-up. We examined the impact of distal popliteal and tibial runoff on long-term outcomes of SFA interventions for claudication. A prospective database of patients undergoing endovascular treatment of the SFA between 1986 and 2007 was queried. Patients with Rutherford symptom classifications 1, 2, and 3 were selected; those with concomitant tibial interventions were excluded. Angiograms were reviewed preoperatively in all cases to assess distal popliteal and tibial runoff and scored according to modified Society for Vascular Surgery criteria for both vessels such that a higher score implies worse runoff (minimum 1, maximum 19). Three run-off score groups were identified: <5 (good), 5-10 (compromised), and >10 (poor). Kaplan-Meier survival analyses were performed to assess time-dependent outcomes. Multivariate and factor analyses were performed. There were 481 limbs in 347 patients (70% male, average age 66 years) that underwent endovascular SFA treatment for claudication: 87% had hypertension, 51% had diabetes mellitus, 67% had hyperlipidemia, and 16% had chronic renal insufficiency (1% on hemodialysis). Technical success was 92%, with 63% SFA undergoing angioplasty, 26% SFA undergoing primary stenting, and 3% SFA undergoing atherectomy. Overall mortality was 1.1% and overall morbidity was 17% at 90 days after the procedure. At 5 years, vessels with compromised and poor runoff had significantly lower freedom from recurrent symptoms and lower freedom from restenosis. Primary and assisted primary patency rates were significantly worse in patients with poor runoff. However, secondary patency was equivalent between the groups. Compromised or poor runoff was associated with incremental lower limb salvage. Following SFA percutaneous interventions for claudication, runoff can identify patients more likely to develop restenosis and recurrent symptoms and, more importantly, those at higher risk of limb loss. Defining such subgroups allows a clear risk stratification of patients with claudication and can guide the intensity of surveillance in the outpatient setting.

Nitrotyrosine and chlorotyrosine: clinical significance and biological functions in the vascular system.

The heme-containing enzyme myeloperoxidase (MPO) is both present and active in inflammatory conditions. This enzyme is potentiated by its formation of multiple inflammatory mediators. The two most common mediators are the modified tyrosines: nitrotyrosine and 3-chlorotyrosine. Along with other modified tyrosines, these molecules have been found to be elevated in atherosclerosis, lung disease, sepsis, vasculitis, and other inflammatory diseases. By treating some of these diseases, the levels of modified tyrosines have been shown to decrease. There have been a wide range of animal models designed to study the in vivo effects of these tyrosine molecules. In addition, there are also several reports in the literature of the in vitro actions of modified tyrosine molecules demonstrated by various cell-culture models. The purpose of this review is to evaluate the clinical significance and biological functions of these modified tyrosine molecules in atherosclerosis as well as a variety of other inflammatory conditions. It is timely information because of their association with diseases as well as lack of overview of their molecular actions. This review will focus on the formation, clinical significance, and animal and cell-culture models of these important molecules.

Phenotypic diversity of the lung vasculature in experimental models of metastases.

In vivo phage display is a screening method in which peptides homing to specific vascular beds are selected after IV administration of a random peptide library. This strategy has revealed a vascular address system that allows tissue-specific targeting of normal blood vessels and angiogenesis-related targeting of tumor blood vessels by selected peptides. Many vascular receptors or "addresses" targeted by homing peptides have been identified. One such vascular receptor of normal lung endothelium is membrane dipeptidase (MDP), which was found by in vivo phage display to bind the tripeptide motif gly-phe-glu (GFE). Our studies with GFE peptide and lung vasculature suggest that MDP mediates cancer cell adhesion to lung vasculature and the development of lung metastases, but that MDP is not present in the vasculature of lung metastases. MDP appears to occupy a vascular distribution that is similar to the pulmonary artery circulation. These results demonstrate the promise of defining critical functional and anatomic characteristics of endothelial cells in lung and other organs by in vivo phage display.

Carotid artery stenting with neuroprotection: assessing the learning curve and treatment outcome.

PURPOSE: Carotid artery stenting (CAS) has emerged as an acceptable treatment alternative in high-risk patients with carotid stenosis. The purpose of this study was to assess the effect of the learning curve on treatment complications and the clinical outcomes of CAS. METHODS: Clinical variables and treatment outcomes of 200 consecutive CAS procedures in 182 patients (mean age 72 years) with carotid stenosis > or = 70% during a 40-month period were analyzed. Four sequential groups (groups I, II, III, and IV) of 50 consecutive interventions were compared with regard to technical success, periprocedural complications, and treatment outcomes. RESULTS: Treatment indications and relevant risk factors were similar among the 4 groups. The overall technical success and combined 30-day stroke and death rates were 98% and 2.5%, respectively. An increase in the technical success rate was noted in the latter 3 groups compared with group I (P < .05). Total procedural time and contrast volume were significantly higher in group I compared with the latter 3 groups (P < .05). The intraoperative anticoagulation regimen was changed from intravenous heparin combination to bivalirudin after the first 54 patients, which resulted in decreased bleeding complications in groups III and IV (P = 0.03) compared with the first group. The 30-day stroke and death rate in groups I and II were 8% and 2%, respectively, and was decreased significantly in groups III and IV (0% and 0%, respectively, P < .05). A Cox regression model identified procedural volume (P = .03) as a predictor of decreased complication rate. CONCLUSIONS: CAS with neuroprotection can provide excellent treatment outcomes. Our experience demonstrates a procedure-associated learning curve as evidenced by decreased procedure-related complications, fluoroscopic time, and contrast volume occurring with increased physician experience. Procedural success was also enhanced partly by endovascular device refinement and an improved anticoagulation regimen. Successful CAS outcomes can be achieved once physicians overcome the initial procedure-related learning curve.

What is the learning curve for carotid artery stenting with neuroprotection? Analysis of 200 consecutive cases at an academic institution.

Carotid artery stenting (CAS) has emerged as an acceptable treatment alternative in high-risk patients with carotid stenosis. This study assessed the effect of the learning curve on treatment complications and clinical outcome of CAS. Clinical variables and treatment outcomes of 200 consecutive CAS procedures in 182 patients (mean age, 72 years) with carotid stenosis of 70% or greater during a 40-month period were analyzed. Technical success, periprocedural complications, and treatment outcomes were compared in four sequential groups (group I, II, III, and IV) of 50 consecutive interventions. Treatment indications and relevant risk factors were similar among the four groups. The overall technical success was 98%, and the combined 30-day stroke and death rates was 2.5%. An increase in the technical success rate was noted in the latter three groups compared with group I (P < .05). Total procedural time and contrast volume were significantly higher in group I compared with the latter three groups (P < .05). The intraoperative anticoagulation regimen was changed from an intravenous heparin combination to bivalirudin after the first 54 cases, resulting in reduced bleeding complications in groups III and IV (P = .03) compared with group I. The 30-day stroke and death rate in groups I and II was 8% and 2%, which was reduced significantly to 0% in groups III and IV (P < .05). A Cox regression model identified procedural volume (P = .03) as a predictor of a reduced complication rate. Carotid artery stenting with neuroprotection can provide excellent treatment outcome. Our experience demonstrates a procedural-associated learning curve, as evidenced by the reduced procedural-related complications, fluoroscopic time, and contrast volume that occurred with an increase in physician experience. The procedural success is also enhanced partly by endovascular device refinement and improved anticoagulation regimen. Successful outcome of CAS can be achieved once physicians overcome the initial procedural-related learning curve.

Herpesvirus-based infectious titering of recombinant adeno-associated viral vectors.

Studies in animals and human clinical trials demonstrate the safety and persistence of recombinant adeno-associated viral (rAAV) serotype 2 vectors in a variety of tissues. rAAV vectors of other serotypes are also being developed for efficient gene transfer. To date, the literature describing these vectors has relied on physical or transducing titers to determine dose, but few, if any, infectious titers have been presented. This is due in large part to the lack of reagents and methods that would facilitate the infectious titering of vectors other than serotype 2. Here, we describe reagents and methods for infectious titering of AAV2 ITR-containing vectors pseudotyped with other AAV capsid serotypes and demonstrate their utility by titering pseudotyped rAAV1 or rAAV5 vectors. Cell lines are screened for optimal transduction using a vector of a particular serotype that expresses a marker transgene. Once a cell line and vector serotype are matched, a recombinant herpes simplex virus vector expressing AAV2 rep and cap genes provides helper functions that amplify the rAAV vector genome. The vector genomes are then detected and a titer is calculated. These methods generate reliable infectious titers for AAV vectors of different serotypes, thus enhancing product characterization and reducing risk in future clinical applications.

Gene therapy for sarcoma utilizing adenoviral transfer of the beta-glucuronidase and bax genes and an anthracyline prodrug.

BACKGROUND: When acted on by beta-glucuronidase (BG), HMR1826 is metabolized to doxorubicin. Use of this prodrug with adenoviral transfer of beta-glucuronidase (AdBG) is limited by the drug's inability to enter cells and intracellular retention of BG after transduction. We evaluated a system combining AdBG, transfer of the proapoptotic gene bax (AdBax) at a low multiplicity of infection, and HMR1826 administration. MATERIALS AND METHODS: Fibrosarcoma cells were treated with AdBG alone, AdBG plus HMR1826, AdBG followed by beta-galactosidase (AdLacZ) plus HMR1826, and AdBG followed by AdBax with no prodrug. In the experimental group, cells were transfected with AdBG, followed by AdBax plus HMR1826. Viability was measured 24 h after transfection and prodrug administration. Western blots for BG were performed on cell lysates and supernatants. RESULTS: Minimal cellular killing was noted in the AdBG alone, AdBG plus HMR 1826, or AdBG:AdLacZ plus HMR 1826 groups, and Western blot did not demonstrate BG in the supernatant even though all AdBG-transfected cell lysates were positive. Cell killing was noted in the AdBG:AdBax group, but less than in the AdBG:AdBax plus HMR 1826 group (without prodrug versus with prodrug: 1:1 to 55.5% versus 75.9%, 5:1 to 10.0% versus 75.9%, 10:1 7.6% versus 49.0%, 20:1 4.6% versus 24.9%, P = 0.037). Western blot demonstrated BG in the supernatant of the AdBG:AdBax groups. CONCLUSIONS: We have devised a novel enzyme prodrug method of killing tumor cells and engendering a bystander effect. AdBax leads to BG release from dying cells after AdBG transduction and conversion of HMR1826 to an active anthracycline.