His Bundle Pacing: Predicting Mortality and Major Complications in Mid-Term Follow-Up.

Introduction: His bundle pacing (HBP) is suitable for 80% of patients with any indication for permanent pacemaker implantation, with a clinical benefit compared to right ventricular pacing (RVP). Although complications and mortality related to RVP are widely reported in the literature, data on HBP are limited. This study aimed to analyze HBP complications and outcomes in the short-term (up to 30 days) and long-term (up to the following 24 months) follow-up (F/U). Materials and Methods: The study includes 373 patients aged ≥ 18, enrolled from October 2015 to May 2019 in a single-center HBP prospective registry conducted in the Department of Electrocardiology, Upper Silesian Medical Centre of the Medical University of Silesia in Katowice, Poland. Mortality and HBP complications were used as end-points: during hospitalization and up to 30 days (short-term F/U), and for each F/U point-six months, 12 months, and 24 months after the procedure (long-term F/U). Results: Successful HBP was achieved in 252 patients (68%), with an increasing success rate during consecutive years: 57% in 2015-2016 and 73% in 2017-2019. Complications were found in 8.4% of patients (21/252) in short-term F/U and 5.8% (13/224), 5.5% (11/201), and 6.9% (12/174) at six months, 12 months, and 24 months, respectively. There were no deaths during the first 30 days. However, 26 patients (10.3%) died within 24 months. A left ventricular ejection fraction (LVEF) ≤ 34% was the only independent predictor of all-cause mortality or any major complication in the 24-month F/U. Conclusions: This single-center study reported a low risk of mortality and complications associated with HBP at the short-term F/U. However, during the long-term F/U, we observed a higher but acceptable risk of major complications, with a lower LVEF being an independent predictor of the composite end-point of all-cause mortality or any major complication.

The Effects of His Bundle Pacing Compared to Classic Resynchronization Therapy in Patients with Pacing-Induced Cardiomyopathy.

Pacing-induced cardiomyopathy (PICM) is among the most common right ventricular pacing complications. Upgrading to cardiac resynchronization therapy (CRT) is the recommended treatment option. Conduction system pacing with His bundle pacing (HBP) has the potential to restore synchronous ventricular activation and can be an alternative to biventricular pacing (BVP). Patients with PICM scheduled for a system upgrade to CRT were included in the prospective cohort study. Either HBP or BVP was used for CRT. Electrocardiographic, clinical, and echocardiographic measurements were recorded at baseline and six-month follow-up. HBP was successful in 44 of 53 patients (83%). Thirty-nine patients with HBP and 22 with BVP completed a 6-month follow-up. HBP led to a higher reduction in QRS duration than BVP, 118.3 ± 14.20 ms vs. 150.5 ± 18.64 ms, p < 0.0001. The improvement in New York Heart Association (NYHA) class by one or two was more common in patients with HBP than those with BiV (p = 0.04). Left ventricular ejection fraction (LVEF) improved in BVP patients from 32.9 ± 7.93% to 43.9 ± 8.07%, p < 0.0001, and in HBP patients from 34.9 ± 6.45% to 48.6 ± 7.73%, p < 0.0001. The improvement in LVEF was more considerable in HBP patients than in BVP patients, p = 0.019. The improvement in clinical outcomes and left ventricle reverse remodeling was more significant with HBP than BVP. HBP can be a valid alternative to BVP for upgrade procedures in PICM patients.

The usefulness of His bundle pacing in a heterogeneous population of patients with impaired left ventricular systolic function.

BACKGROUND: His bundle pacing (HBP) maintains a physiological activation pattern of ventricular activation, and in patients with intraventricular conduction delay (IVCD) it can normalize wide QRS duration. METHODS: A total of 181 patients from the HBP registry were enrolled into a the study, which was conducted at the Department of Electrocardiology in Katowice, Poland. The patients had left ventricular ejection fraction (LVEF) < 50% and were implanted between November 2015 and April 2019. The HBP indications were as follows: 1) bradycardia and atrioventricular conduction disturbances with expected high pacing burden, 2) IVCD, LVEF ≤ 35%, with an indication for resynchronization therapy, 3) the need to upgrade to resynchronization therapy due to pacing-induced cardiomyopathy. Pacing parameters and echocardiographic and clinical data were assessed for up to 2 years of follow-up (FU). RESULTS: His bundle pacing was successful in 154 (85.1%) patients. Eighty-two patients completed a 6-month FU. The mean age was 70.6 ± 9.23 years, and 79% were males. At 6 months FU LVEF improved from 35.3 ± 8.22% to 43.1 ± 10.14% (p < 0.0001), and indexed left ventricular end-systolic volume (LVESVi) decreased from 63.1 ± 25.21 mL/m² to 51.9 ± 22.79 mL/m² (p < 0.0001). In 53.1%, the LVESVi reduction was greater than 15%. The improvement in LVEF and LVESVi was also observed after 24 months of FU. CONCLUSIONS: His bundle pacing in permanently paced patients when LVEF is reduced below 50% is associated with improvement in LVEF and reverse left ventricle remodeling.

[Kinesiophobia in patients with cardiovascular disease].

OBJECTIVE: Introduction: Kinesiophobia - a fear of physical activity - is a common and worsening rehabilitation outcomes phenomenon in patients with cardiovascular diseases. The aim: To assess the level of kinesiophobia in relation to heart's function evaluated using echocardiography and clinical parameters in patients with cardiovascular disease. PATIENTS AND METHODS: Material and methods:101 patients (28 women) aged 61,9±13,56 years and hospitalized for implantation or replacement of a pacemaker or cardioverter-defibrillator were included in the study. Their heart's function and morphology were evaluated echocardiographically. Level of kinesiophobia was evaluated with the Polish version of Tampa Scale of Kinesiophobia Heart (TSK-Heart) questionnaire. RESULTS: Results: The TSK score in these patients was 41,6±5,39. It's value was increasing with age (p=0,0264), was higher in women than in men (43,5±5,36 vs. 40,8±5,27, p=0,0287) and in patients with coronary artery disease (42,3±6,28 vs. 40,9±4,62, p=0,031). In patients with heart failure, it was decreasing with an increase of body mass index (p=0,0185). Severe mitral insufficiency resulted in higher index value in comparison with moderate or mild one (42,7±4,05 vs. 40,9 ± 5,58, p=0,0369). The TSK index increases with a decrease in tricuspid annular plane systolic excursion (p=0,0033). Patients in NYHA IV class exhibited higher TSK value than those in lower classes (p<0,001). An inverse dependency of TSK index value and hemoglobin level were established (p=0,0041). CONCLUSION: Conclusions: In patients with cardiovascular diseases, kinesiophobia has multicausal nature and is higher in NYHA IV patients. The independent predictors of kinesiophobia are right ventricular dysfunction and anemia.

Patient-Derived Tumor Xenografts Are Susceptible to Formation of Human Lymphocytic Tumors.

Patient-derived xenograft (PDX) tumor models have emerged as a new approach to evaluate the effects of cancer drugs on patients' personalized tumor grafts enabling to select the best treatment for the cancer patient and providing a new tool for oncology drug developers. Here, we report that human tumors engrafted in immunodeficient mice are susceptible to formation of B-and T-cell PDX tumors. We xenografted human primary and metastatic tumor samples into immunodeficient mice and found that a fraction of PDX tumors generated from patients' samples of breast, colon, pancreatic, bladder and renal cancer were histologically similar to lymphocytic neoplasms. Moreover, we found that the first passage of breast and pancreatic cancer PDX tumors after initial transplantation of the tumor pieces from the same human tumor graft could grow as a lymphocytic tumor in one mouse and as an adenocarcinoma in another mouse. Whereas subcutaneous PDX tumors resembling human adenocarcinoma histology were slow growing and non-metastatic, we found that subcutaneous PDX lymphocytic tumors were fast growing and formed large metastatic lesions in mouse lymph nodes, liver, lungs, and spleen. PDX lymphocytic tumors were comprised of B-cells which were Epstein-Barr virus positive and expressed CD45 and CD20. Because B-cells are typically present in malignant solid tumors, formation of B-cell tumor may evolve in a wide range of PDX tumor models. Although PDX tumor models show great promise in the development of personalized therapy for cancer patients, our results suggest that confidence in any given PDX tumor model requires careful screening of lymphocytic markers.

A randomized phase II presurgical trial of transdermal 4-hydroxytamoxifen gel versus oral tamoxifen in women with ductal carcinoma in situ of the breast.

PURPOSE: Local transdermal therapy to the breast may achieve effective target-organ drug delivery, while diminishing systemic effects. We conducted a randomized, double-blind, placebo-controlled phase II trial comparing transdermal 4-hydroxytamoxifen gel (4-OHT) to oral tamoxifen (oral-T) in women with ductal carcinoma in situ (DCIS). METHODS: Twenty-seven pre- and postmenopausal women were randomized to 4-OHT (4 mg/day) or oral-T (20 mg/day) for 6 to 10 weeks before surgery. Plasma, nipple aspirate fluid, and breast adipose tissue concentrations of tamoxifen and its major metabolites were determined by liquid chromatography/tandem mass spectrometry. The primary endpoint was Ki67 labeling in DCIS lesions, measured by immunohistochemistry. In plasma, insulin-like growth factor-1 (IGFI), sex hormone-binding globulin (SHBG), and coagulation protein concentrations were determined. RESULTS: Posttherapy Ki67 decreased by 3.4% in the 4-OHT and 5.1% in the oral-T group (P ≤ 0.03 in both, between-group P = 0. 99). Mean plasma 4-OHT was 0.2 and 1.1 ng/mL in 4-OHT and oral groups, respectively (P = 0.0003), whereas mean breast adipose tissue concentrations of 4-OHT were 5.8 ng/g in the 4-OHT group and 5.4 ng/g in the oral group (P = 0.88). There were significant increases in plasma SHBG, factor VIII, and von Willebrand factor and a significant decrease in plasma IGFI with oral-T, but not with 4-OHT. The incidence of hot flashes was similar in both groups. CONCLUSIONS: The antiproliferative effect of 4-OHT gel applied to breast skin was similar to that of oral-T, but effects on endocrine and coagulation parameters were reduced. These findings support the further evaluation of local transdermal therapy for DCIS and breast cancer prevention.

Improving diversity in cancer research trials: the story of the Cancer Disparities Research Network.

The participation of racial and ethnic minorities and underserved populations in clinical trials is a critical link between scientific innovation and improvements in health care delivery and health outcomes. However, these population groups continue to be underrepresented in research. We describe the development of the Cancer Disparities Research Network (CDRN) to improve minority and underserved populations' participation in biobanking research. Between February and October 2011, we conducted a regional assessment to identify challenges and opportunities for cancer trials and biobanking research across the CDRN. Representatives from ten CDRN biorepository facilities completed an online survey assessing their facilities' minority biospecimen collection, biobanking practices, and education/outreach initiatives. Representatives of eight facilities also participated in stakeholder interviews. The majority (70%) of facilities reported that specimens were available for research, although only one tenth of these specimens were from non-White patients. Most facilities collected a patient's age, gender, race, medical history, and ethnicity with samples; however, less than half also collected family health history, education level, household income, or primary language spoken. In addition, few institutions collected Asian or Hispanic subgroup information. Only a few reported biospecimen collection outreach programs specifically targeting minority and underserved populations. Biospecimen directors and administrators indicated that funding, biospecimen sharing procedures, and standardization barriers limited their facilities from collaborating in biospecimen collection programs, despite their great interest. These findings suggest that the CDRN can provide opportunities for collaboration, resource sharing, and fostering of research ideas to address cancer disparities in biospecimen research.

Novel Phenotypic Fluorescent Three-Dimensional Co-Culture Platforms for Recapitulating Tumor in vivo Progression and for Personalized Therapy.

Because three-dimensional (3D) in vitro models are more accurate than 2D cell culture models and faster and cheaper than animal models, they have become a prospective trend in the biomedical and pharmaceutical fields, especially for personalized and targeted therapies. Because appropriate 3D models can be customized to mimic the in vivo microenvironment wherein various cell populations grow within an intricate but well organized extracellular matrix (ECM), they can accurately recapitulate physiological and pathophysiological progressions. The majority of cancers are carcinomas, which originate from epithelial cells, and dynamically interact with non-malignant cells including stromal cells (fibroblasts), vascular cells (endothelial cells and pericytes), immune cells (macrophages and mast cells), and the ECM. Employing a tumor monoclonal colony, tumor xenograft or patient cancer biopsy into an in vivo-like microenvironment, the native signaling pathways, cell-cell and cell-matrix interactions, and cell phenotypes are preserved and our fluorescent phenotypic 3D co-culture platforms can then accurately recapitulate the tumor in vivo scenario including tumor induced angiogenesis, tumor growth, and metastasis. In this paper, we describe a robust and standardized method to co-culture a tumor colony or biopsy with different cell populations, e.g., endothelial cells, immune cells, pericytes, etc. The procedures for recovering cells from the co-culture for molecular analyses, imaging, and analyzing are also described. We selected ECM solubilized extract derived from Engelbreth-Holm-Swam sarcoma cells. Because the 3D co-culture platforms can provide drug chemosensitivity data within 9 days that is equivalent to the results generated from mouse tumor xenograft models in 50 days, the 3D co-culture platforms are more accurate, efficient, and cost-effective and may replace animal models in the near future to predict drug efficacy, personalize therapies, prevent drug resistance, and improve the quality of life.

Central pathology review for phase III clinical trials: the enabling effect of virtual microscopy.

CONTEXT: Central pathology review (CPR) was initially designed as a quality control measure. The potential of CPR in clinical trials was recognized as early as in the 1960s and quickly became embedded as an integral part of many clinical trials since. OBJECTIVE: To review the current experience with CPR in clinical trials, to summarize current developments in virtual microscopy, and to discuss the potential advantages and disadvantages of this technology in the context of CPR. DATA SOURCES: A PubMed (US National Library of Medicine) search for published studies was conducted, and the relevant articles were reviewed, accompanied by the authors' experience at their practicing institution. CONCLUSIONS: The review of the available literature strongly suggests the growing importance of CPR both in the clinical trial setting as well as in second opinion cases. However, the currently applied approach significantly impedes efficient transfer of slides and patient data. Recent advances in imaging, digital microscopy, and Internet technologies suggest that the CPR process may be dramatically streamlined in the foreseeable future to allow for better diagnosis and quality assurance than ever before. In particular, whole slide imaging may play an important role in this process and result in a substantial reduction of the overall turnaround time required for slide review at the central location. Above all, this new approach may benefit the large clinical trials organized by oncology cooperative groups, since most of those trials involve complicated logistics owing to enrollment of large number of patients at several remotely located participating institutions.

Identification and characterization of nucleolin as a COUP-TFII coactivator of retinoic acid receptor ß transcription in breast cancer cells.

INTRODUCTION: The orphan nuclear receptor COUP-TFII plays an undefined role in breast cancer. Previously we reported lower COUP-TFII expression in tamoxifen/endocrine-resistant versus sensitive breast cancer cell lines. The identification of COUP-TFII-interacting proteins will help to elucidate its mechanism of action as a transcriptional regulator in breast cancer. RESULTS: FLAG-affinity purification and multidimensional protein identification technology (MudPIT) identified nucleolin among the proteins interacting with COUP-TFII in MCF-7 tamoxifen-sensitive breast cancer cells. Interaction of COUP-TFII and nucleolin was confirmed by coimmunoprecipitation of endogenous proteins in MCF-7 and T47D breast cancer cells. In vitro studies revealed that COUP-TFII interacts with the C-terminal arginine-glycine repeat (RGG) domain of nucleolin. Functional interaction between COUP-TFII and nucleolin was indicated by studies showing that siRNA knockdown of nucleolin and an oligonucleotide aptamer that targets nucleolin, AS1411, inhibited endogenous COUP-TFII-stimulated RARB2 expression in MCF-7 and T47D cells. Chromatin immunoprecipitation revealed COUP-TFII occupancy of the RARB2 promoter was increased by all-trans retinoic acid (atRA). RARß2 regulated gene RRIG1 was increased by atRA and COUP-TFII transfection and inhibited by siCOUP-TFII. Immunohistochemical staining of breast tumor microarrays showed nuclear COUP-TFII and nucleolin staining was correlated in invasive ductal carcinomas. COUP-TFII staining correlated with ERα, SRC-1, AIB1, Pea3, MMP2, and phospho-Src and was reduced with increased tumor grade. CONCLUSIONS: Our data indicate that nucleolin plays a coregulatory role in transcriptional regulation of the tumor suppressor RARB2 by COUP-TFII.

Estradiol modulates post-ischemic cerebral vascular remodeling and improves long-term functional outcome in a rat model of stroke.

We previously observed that 17ß-estradiol (E2) augments ischemic borderzone vascular density 10 days after focal cerebral ischemia-reperfusion in rats. We now evaluated the effect of E2 on vascular remodeling, lesional characteristics, and motor recovery up to 30 days after injury. Peri-lesional vascular density in tissue sections from rats treated with 0.72 mg E2 pellets was higher compared to 0.18 mg E2 pellets or placebo (P) pellets: vascular density index, 1.9 ± 0.2 (0.72 mg E2) vs. 1.4 ± 0.2 (0.18 mg E2) vs. 1.5 ± 0.4 (P), p=0.01. This was consistent with perfusion magnetic resonance imaging (MRI) measurements of lesional relative cerebral blood flow (rCBF): 1.89 ± 0.32 (0.72 mg E2) vs. 1.32 ± 0.19 (P), p=0.04. Post-ischemic angiogenesis occurred in P-treated as well as E2-treated rats. There was no treatment-related effect on lesional size, but lesional tissue was better preserved in E2-treated rats: cystic component as a % of total lesion, 30 ± 12 (0.72 mg E2) vs. 29 ± 17 (0.18 mg E2) vs. 61 ± 29 (P), p=0.008. Three weeks after right middle cerebral artery territory injury, rats treated with 0.72 mg E2 pellets used the left forelimb more than P-treated or 0.18 mg E2-treated rats: limb use asymmetry score, 0.09 ± 0.43 (0.72 mg E2) vs. 0.54 ± 0.12 (0.18 mg E2) vs. 0.54 ± 0.40 (P), p=0.05. We conclude that treatment with 0.72 mg E2 pellets beginning one week prior to ischemia/reperfusion and continuing through the one-month recovery period results in augmentation of lesional vascularity and perfusion, as well as improved motor recovery.

The utility of fine needle aspiration for diagnosis of extrapulmonary coccidioidomycosis: a case report and discussion.

Coccidioidomycosis typically presents as pneumonia, but rarely manifests as extrapulmonary disease. We describe a case of coccidioidal infection that presented as a neck mass and was diagnosed by fine needle aspiration (FNA). Initial clinical suspicion was for mycobacterial infection. Several modalities are available for the detection of Coccidioides species, but culture has been the mainstay of diagnosis. FNA provides a relatively noninvasive and effective modality for tissue-based diagnosis based on characteristic histological findings. It allows the additional advantage of early on-site identification, allowing for triage of the specimen, notification of laboratory staff and prompt initiation of treatment. The case herein described is intended to demonstrate an atypical presentation of extrapulmonary coccidioidomycosis and highlight the utility of FNA for diagnosis of such lesions. Clinicians should be aware of the unique advantages of FNA for evaluation of lesions of infectious etiology.

Fine-needle aspiration of renal cell carcinoma: is accurate Fuhrman grading possible on cytologic material?

The Fuhrman grading system of renal cell carcinoma (RCC) consists of four grades based on nuclear size/contour and nucleolar conspicuousness. Fuhrman grading of histpathologic material is an independent prognostic parameter for RCC. Although widely used in surgical pathology, Fuhrman grading is not routinely performed on cytologic material. Thirty-three cases of renal fine needle aspirations (FNAs) with histologically proven RCC were retrieved from the cytopathology archives at Johns Hopkins Hospital. Fuhrman grade was determined independently and blindly by three faculty cytopathologists and compared with the Fuhrman grade of the subsequent surgical pathology specimen. The 33 resection specimens had the following Fuhrman grades: 0/33, grade I; 24/33 (73%), grade II; 9/33 (27%), grade III; and 0/33, grade IV. After Fuhrman grading was applied to the FNA material, diagnostic sensitivity was 83% for grade II versus 44% for grade III. The specificity and accuracy were 50 and 75%, respectively, for grade II versus 100% and 84% for grade III. Diagnostic sensitivity for grade II tumors ranged from 38 to 83%, grade III 44-62%. Diagnostic specificity for grade II tumors ranged from 50 to 78%, grade III 80-100%. Accuracy ranged from 48 to 75% for grade II and 75-87% for grade III. Using a two-tier grading model, accuracy improved to 84.2%. In our experience, Fuhrman grading of FNA specimens yielded variable results. There was only moderate agreement between cytopathologists, with an overall tendency to undergrade the tumor when compared with the resection specimen. Averaging the participants' grading and using a two-tier instead of four-tier system improved overall performance.

Phase I trial of oxaliplatin, infusional 5-fluorouracil, and leucovorin (FOLFOX4) with erlotinib and bevacizumab in colorectal cancer.

RATIONALE: This phase I study was conducted to determine the maximum tolerated dose (MTD) of erlotinib, an oral epidermal growth factor receptor tyrosine kinase inhibitor, with 5-fluorouracil/leucovorin/oxaliplatin (FOLFOX4) in patients with advanced colorectal cancer (CRC). Bevacizumab was later included as standard of care at the MTD. PATIENTS AND METHODS: Patients received FOLFOX4 with escalating doses of erlotinib: dose level (DL) 1, 50 mg; DL 2, 100 mg; and DL 3, 150 mg once daily continuously. Bevacizumab 5 mg/kg days 1 and 15 was added at the MTD upon Food and Drug Administration approval. Correlative studies included pharmacokinetics, pharmacodynamics was assessed in paired skin biopsies, and fluorodeoxyglucose positron emission tomography scans. RESULTS: Fifteen patients received 60 cycles (120 FOLFOX treatments). Two dose-limiting toxicities (DLTs) were seen at DL 3: intolerable grade 2 rash (Common Terminology Criteria for Adverse Events version 2) lasting > 1 week, and grade 4 neutropenia. Dose level 2 was expanded to 6 more patients, this time adding bevacizumab, and 1 DLT of grade 3 mucositis occurred. As expected, the primary toxicities were cytopenias, diarrhea, rash, and fatigue. There were 2 occurrences of pneumatosis. One patient experienced an unrelated grade 4 myocardial infarction before starting chemotherapy. No pharmacokinetic drug interactions were observed. The Response Evaluation Criteria in Solid Tumors response rate was 11 of 14 (78%), median progression-free survival was 9.5 months, and median overall survival was 30 months. Three patients are currently alive > 3 years, with 1 having no evidence of disease. CONCLUSION: The MTD of erlotinib with FOLFOX4 with or without bevacizumab is 100 mg daily. The regimen appeared to increase toxicity but showed activity in patients with CRC.

Localization of angiopoietin-1 and Tie2 immunoreactivity in rodent ependyma and adjacent blood vessels suggests functional relationships.

Angiopoietin-1 (Angpt1; previously Ang-1) participates in vascular maintenance and remodeling. In the current study, we investigated the distribution of Angpt1 protein in rat brain. We detected Angpt1 immunoreactivity (IR) in cerebral blood vessels, cuboidal ependyma, and tanycytes, which are specialized hypothalamic bipolar ependymal cells. We also evaluated patterns of IR of endothelium-specific receptor tyrosine kinase 2 (Tie2, the receptor for Angpt1). Tie2 IR was present in Angpt1-immunoreactive cuboidal ependyma in a membranous pattern, suggesting an autocrine or paracrine role for Angpt1-Tie2. Tie2 IR was also associated with peri-ependymal blood vessels, some of which were contacted by tips of Angpt1-immunoreactive tanycyte processes, implying a potential functional ligand-receptor interaction mediating communication between the cerebrospinal fluid and vascular compartments. Because we previously found that cerebral Angpt1 expression was modulated by 17beta-estradiol (E2), and because some tanycyte functions are modulated by E2, we tested the hypothesis that E2 affects ependymal and tanycyte Angpt1 expression in vivo. No gross E2 effect on the ependymal pattern of Angpt1 IR or cerebral Angpt1 protein content was observed.

Estradiol augments peri-infarct cerebral vascular density in experimental stroke.

Peri-infarct increase of vascular density has been observed in animals and in humans with ischemic stroke. Increased peri-infarct vascular density correlates with improved functional outcome after stroke. We hypothesized that pre-treatment with estradiol will increase post-ischemic peri-infarct capillary density in a rat model of transient ischemic stroke. Estradiol, compared to placebo, augmented post-ischemic peri-infarct vascular density by 22% 10 days after stroke. Recovery of forelimb function was not improved with estradiol treatment on day three and nine post-stroke. Loss of estradiol may limit repair in the peri-infarct region by limiting angiogenesis, but functional significance in stroke recovery requires further investigation.

Characterization of musculoskeletal lesions on 3-T proton MR spectroscopy.

OBJECTIVE: The purpose of our study was to determine the feasibility and value of proton MR spectroscopy at 3 T for characterizing musculoskeletal tumors. SUBJECTS AND METHODS: At 3 T, 18 patients with musculoskeletal lesions (four histologically proven to be malignant, 14 proven benign histologically or at clinical follow-up) underwent 23 MR spectroscopy studies, 20 with a single-voxel technique and three with a multivoxel technique. Seventeen patients were imaged with a surface coil and six with a body coil. Choline signal (3.2 ppm) was measured in each voxel and expressed relative to background noise as signal-to-noise ratio (SNR). Choline SNRs of malignant tumors and benign lesions were compared. RESULTS: Diagnostic spectra were obtained in 20 of 23 lesions. For malignant lesions (osteosarcoma with two MR spectroscopy sites, metastasis, grade 1 sarcoma), choline SNRs were 5.2 and 4.2 (performed with body coil) and 4.8 and 18.7 (performed with surface coil), respectively. For benign lesions (neurofibroma, two stress reactions, bone cyst, hemangioma, lipoma, Baker cyst), choline SNR was 6.3 (with surface coil), 5.5 (with surface coil), and not detected for five cases. Seven postoperative patients with myocutaneous flaps showed either the typical spectrum of muscle or negligible choline. Only a water peak existed in a bone cyst and a significant lipid peak in a lipoma. Choline SNRs were different for malignant and benign lesions (11.7 vs 2.3, p = 0.04, as performed with a surface coil). CONCLUSION: At 3 T, both single-voxel and multivoxel MR spectroscopy are feasible. Proton MR spectroscopy is a potential noninvasive tool for characterizing lesion composition and malignant activity.

An in vivo platform for translational drug development in pancreatic cancer.

Effective development of targeted anticancer agents includes the definition of the optimal biological dose and biomarkers of drug activity. Currently available preclinical models are not optimal to this end. We aimed at generating a model for translational drug development using pancreatic cancer as a prototype. Resected pancreatic cancers from 14 patients were xenografted and expanded in successive groups of nude mice to develop cohorts of tumor-bearing mice suitable for drug therapy in simulated early clinical trials. The xenografted tumors maintain their fundamental genotypic features despite serial passages and recapitulate the genetic heterogeneity of pancreatic cancer. The in vivo platform is useful for integrating drug screening with biomarker discovery. Passages of tumors in successive cohorts of mice do not change their susceptibility to anticancer agents and represent a perpetual live bank, facilitating the application of new technologies that will result in the creation of an integrated stable database of tumor-drug response data and biomarkers.

Immunohistochemical and genetic evaluation of deoxycytidine kinase in pancreatic cancer: relationship to molecular mechanisms of gemcitabine resistance and survival.

Gemcitabine is considered the standard first-line therapy for patients with advanced pancreatic cancer. More recent strategies have focused on improving the efficacy of gemcitabine by either improving the method of delivery or by combining gemcitabine with other non-cross-resistant chemotherapy agents or with small-molecule drugs. However, the clinical benefits, response rates, and duration of responses have been modest. Deoxycytidine kinase (dCK) is the rate-limiting enzyme involved in the metabolism of gemcitabine. The expression of dCK has been postulated to be correlative of gemcitabine resistance. We determined the relationship of dCK immunohistochemical protein expression and/or genetic status of dCK in a panel of human pancreatic cancer tissues and pancreatic cancer cell lines and determined the relationship of these variables to the clinical outcome of patients treated with gemcitabine. We report that dCK protein expression is expressed in the majority of pancreatic cancers analyzed (40 of 44 cases, 91%) and showed a range of labeling intensities ranging from 1+ (labeling weaker in intensity than normal lymphocytes present in same section) to 3+ (labeling greater in intensity than normal lymphocytes present in same section). When labeling intensity was compared with survival, low dCK expression (1+ labeling) was correlated with both overall survival (P < 0.009) and progression-free survival following gemcitabine treatment (P < 0.04). Low dCK labeling intensity was also significantly correlated with patient age (70.3 +/- 8.1 versus 59.8 +/- 7.4 years; P < 0.0006), suggesting that age-related methylation of the dCK gene may account in part for the observed differences. Sequencing of the entire dCK coding sequence in 17 cell lines and 9 patients' cancer tissues with disease progression while on gemcitabine did not identify any mutations, suggesting that genetic alterations of dCK are not a common mechanism of resistance to gemcitabine for this tumor type. Moreover, dCK labeling showed similar patterns and intensities of labeling among matched pretreatment and post-treatment tissues. In summary, pretreatment levels of dCK protein are most correlated with overall survival following gemcitabine treatment and are stable even after resistance to gemcitabine is clinically documented.