Ablative five-fraction stereotactic body radiation therapy for inoperable pancreatic cancer using online MR-guided adaptation

Purpose: Patients with inoperable pancreatic adenocarcinoma have limited options, with traditional chemoradiation providing modest clinical benefit and an otherwise poor prognosis. Stereotactic body radiation therapy for pancreatic cancer is limited by proximity to organs-at-risk (OAR). However, stereotactic magnetic resonance-guided adaptive radiation therapy (SMART) has shown promise in delivering ablative doses safely. We sought to demonstrate the benefits of SMART using a 5-fraction approach with daily on-table adaptation. Methods and Materials: Patients with locally advanced, nonmetastatic pancreatic adenocarcinoma were treated with 50 Gy in 5 fractions (biologically effective dose Results: Forty-four patients were treated with SMART at our institution from 2014 to 2019. Median follow-up from date of diagnosis was 16 months (range, 6.7-51.6). Late toxicity was limited to 2 (4.6%) grade 3 (gastrointestinal ulcers) and 3 (6.8%) grade 2 toxicities (duodenal perforation, antral ulcer, and gastric bleed). Tumor abutted OARs in 35 patients (79.5%) and tumor invaded OARs in 5 patients (11.1%). Reoptimization was performed for 93% of all fractions. Median overall survival was 15.7 months (95% confidence interval, 10.2-21.2), while 1-year and 2-year overall survival rates were 68.2% and 37.9%, respectively. One-year local control was 84.3%. Conclusions: This is the first reported experience using 50 Gy in 5 fractions for inoperable pancreatic cancer. SMART allows this ablative dose with promising outcomes while minimizing toxicity. Additional prospective trials evaluating efficacy and safety are warranted

Characterization of subsurface media from locations up- and down-gradient of a uranium-contaminated aquifer.

The processing of sediment to accurately characterize the spatially-resolved depth profiles of geophysical and geochemical properties along with signatures of microbial density and activity remains a challenge especially in complex contaminated areas. This study processed cores from two sediment boreholes from background and contaminated core sediments and surrounding groundwater. Fresh core sediments were compared by depth to capture the changes in sediment structure, sediment minerals, biomass, and pore water geochemistry in terms of major and trace elements including pollutants, cations, anions, and organic acids. Soil porewater samples were matched to groundwater level, flow rate, and preferential flows and compared to homogenized groundwater-only samples from neighboring monitoring wells. Groundwater analysis of nearby wells only revealed high sulfate and nitrate concentrations while the same analysis using sediment pore water samples with depth was able to suggest areas high in sulfate- and nitrate-reducing bacteria based on their decreased concentration and production of reduced by-products that could not be seen in the groundwater samples. Positive correlations among porewater content, total organic carbon, trace metals and clay minerals revealed a more complicated relationship among contaminant, sediment texture, groundwater table, and biomass. The fluctuating capillary interface had high concentrations of Fe and Mn-oxides combined with trace elements including U, Th, Sr, Ba, Cu, and Co. This suggests the mobility of potentially hazardous elements, sediment structure, and biogeochemical factors are all linked together to impact microbial communities, emphasizing that solid interfaces play an important role in determining the abundance of bacteria in the sediments

Association of Preoperative Risk Factors With Malignancy in Pancreatic Mucinous Cystic Neoplasms: A Multicenter Study

Pancreatic mucinous cystic neoplasms (MCNs) harbor malignant potential, and current guidelines recommend resection. However, data are limited on preoperative risk factors for malignancy (adenocarcinoma or high-grade dysplasia) occurring in the setting of an MCN

The diagnosis of pancreatic mucinous cystic neoplasm and associated adenocarcinoma in males: An eight‐institution study of 349 patients over 15 years

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137278/1/jso24582_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137278/2/jso24582.pd

H2A.Z Acidic Patch Couples Chromatin Dynamics to Regulation of Gene Expression Programs during ESC Differentiation

The histone H2A variant H2A.Z is essential for embryonic development and for proper control of developmental gene expression programs in embryonic stem cells (ESCs). Divergent regions of amino acid sequence of H2A.Z likely determine its functional specialization compared to core histone H2A. For example, H2A.Z contains three divergent residues in the essential C-terminal acidic patch that reside on the surface of the histone octamer as an uninterrupted acidic patch domain; however, we know little about how these residues contribute to chromatin structure and function. Here, we show that the divergent amino acids Gly92, Asp97, and Ser98 in the H2A.Z C-terminal acidic patch (H2A.Z[superscript AP3]) are critical for lineage commitment during ESC differentiation. H2A.Z is enriched at most H3K4me3 promoters in ESCs including poised, bivalent promoters that harbor both activating and repressive marks, H3K4me3 and H3K27me3 respectively. We found that while H2A.Z[superscript AP3] interacted with its deposition complex and displayed a highly similar distribution pattern compared to wild-type H2A.Z, its enrichment levels were reduced at target promoters. Further analysis revealed that H2A.Z[superscript AP3] was less tightly associated with chromatin, suggesting that the mutant is more dynamic. Notably, bivalent genes in H2A.Z[superscript AP3] ESCs displayed significant changes in expression compared to active genes. Moreover, bivalent genes in H2A.Z[superscript AP3] ESCs gained H3.3, a variant associated with higher nucleosome turnover, compared to wild-type H2A.Z. We next performed single cell imaging to measure H2A.Z dynamics. We found that H2A.Z[superscript AP3] displayed higher mobility in chromatin compared to wild-type H2A.Z by fluorescent recovery after photobleaching (FRAP). Moreover, ESCs treated with the transcriptional inhibitor flavopiridol resulted in a decrease in the H2A.Z[superscript AP3] mobile fraction and an increase in its occupancy at target genes indicating that the mutant can be properly incorporated into chromatin. Collectively, our work suggests that the divergent residues in the H2A.Z acidic patch comprise a unique domain that couples control of chromatin dynamics to the regulation of developmental gene expression patterns during lineage commitment.Massachusetts Life Sciences Center (David H. Koch Institute for Integrative Cancer Research at MIT Core Grant P30-CA14051)National Science Foundation (U.S.). Emergent Behaviors of Integrated Cellular Systems (Grant CBET-0939511)MIT Faculty Start-up FundMassachusetts Institute of Technology. Computational and Systems Biology Initiative (Merck & Co. Postdoctoral Fellowship

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Constitutive Secretion in Tetrahymena thermophila ▿ † ‡

The growth, survival, and life cycle progression of the freshwater ciliated protozoan Tetrahymena thermophila are responsive to protein signals thought to be released by constitutive secretion. In addition to providing insights about ciliate communication, studies of constitutive secretion are of interest for evaluating the utility of T. thermophila as a platform for the expression of secreted protein therapeutics. For these reasons, we undertook an unbiased investigation of T. thermophila secreted proteins using wild-type and secretion mutant strains. Extensive tandem mass spectrometry analyses of secretome samples were performed. We identified a total of 207 secretome proteins, most of which were not detected in a set of abundant whole-cell protein identifications. Numerous proteases and other hydrolases were secreted from cells grown in rich medium but not cells transferred to a nutrient starvation condition. On the other hand, we detected the starvation-enhanced secretion of a small number of cytosolic proteins, suggestive of an exosome-like pathway in T. thermophila. Subsets of proteins from the T. thermophila regulated secretion pathway were detected with differential representation across strains and culture conditions. Finally, many secretome proteins had a predicted N-terminal signal sequence but no other annotated characteristic or functional classification. Our work provides the first comprehensive analysis of secreted proteins in T. thermophila and establishes the groundwork for future studies of constitutive protein secretion biology and biotechnology in ciliates

Medical students are accurate in interpreting the presence of pathologic interstitial edema on focused lung ultrasound compared to expert reviewers.

BACKGROUND: Over the past two decades, studies have demonstrated that lung ultrasound is useful in diagnosing alveolar interstitial syndrome, which is seen in patients with decompensated congestive heart failure (CHF). METHODS: We studied medical students performing lung ultrasound on patients admitted to the hospital with a presumed diagnosis of decompensated CHF in a prospective convenience observation study. Two ultrasound fellowship-trained emergency medicine attendings independently reviewed the lung ultrasounds at a later date, blinded to the students\u27 interpretation and other clinical information, to confirm ultrasound findings and assess for inter-rater reliability of the lung ultrasound using intraclass correlation coefficients (ICCs). RESULTS: Thirty-six patients were enrolled in the study resulting in 653 unique lung zones scanned. The zones were imaged and classified as being normal (B-lines \u3c 3) or pathologic (B-lines ≥ 3). The novice scanners\u27 interpretation was compared to expert reviews using ICCs. The ICC was 0.88, with a 95% confidence interval of 0.87 to 0.90, for all lung zones scanned. CONCLUSION: There was almost perfect agreement between novice practitioners and experts when determining the presence of pathologic B-lines in individual patients

Neuroendocrine liver metastasis: The chance to be cured after liver surgery

Background and Objective: Neuroendocrine liver metastasis tumors (NELM) are a heterogeneous group of neoplasms with varied histologic features and a wide range of clinical behaviors. We aimed to identify the fraction of patients cured after liver surgery for NELM. Methods: Cure fraction models were used to analyze 376 patients who underwent hepatectomy with curative intent for NELM. Results: The median and 5-year disease-free survival (DFS) were 4.5 years and 46%, respectively. The probability of being cured from NELM by liver surgery was 44%; the time to cure was 5.1 years. In a multivariable cure model, type of neuroendocrine tumor (NET), grade of tumor differentiation, and rate of liver involvement resulted as independent predictors of cure. The cure fraction for patients with well differentiated NELM from gastrointestinal NET or a functional pancreatic NET, and with <50% of liver-involvement was 95%. Patients who had moderately/poorly differentiated NELM from a non-functional pancreatic NET, and with <50% of liver-involvement was 43%. In the presence of all the three unfavorable prognostic factors (nonfunctional PNET, liver involvement >50%, moderately/poorly differentiation), the cure fraction was 8%. Conclusions: Statistical cure after surgery for NELM is possible, and allow for a more accurate prediction of long-term outcome among patients with NELM undergoing liver resection

A multi-center study of 349 pancreatic mucinous cystic neoplasms: Preoperative risk factors for adenocarcinoma

231 Background: Pancreatic mucinous cystic neoplasms (MCN) are defined by presence of ovarian stroma per WHO 2000 classification. Given their malignant potential, current guidelines recommend resection. However, there are limited data on preoperative risk factors for adenocarcinoma (AC) and high grade dysplasia (HGD) occurring in an MCN. Methods: MCN resections from 2000-2014 at the 8 institutions of the Central Pancreas Consortium were included. Patients with and without AC/HGD were compared. Primary aims were to determine preoperative risk factors for AC/HGD in an MCN and to assess outcomes of MCN-associated AC. Results: Of 1667 resections for pancreatic cystic lesions, 349 pts (21%) had an MCN with 52 (15%) having MCN-associated AC/HGD. Male gender (29 vs 8%; p<0.001), head/neck location (39 vs 13%; p<0.001), increased MCN size (7.2 vs 4.6 cm; p=0.004), radiographic presence of a solid component/mural nodule (54 vs 20%; p<0.001), and duct dilation (43 vs 12%; p<0.001) were associated with AC/HGD compared to benign MCN. All persisted as independent predictors of MCN-associated AC/HGD (Table). AC/HGD was not associated with presence of radiographic septations or preoperative cyst fluid analysis (CEA, amylase, or mucin). Median CA19-9 for patients with AC/HGD was 210 vs 15 U/ml for those without (p=0.001). In the 44 pts with AC, 41 (93%) had lymph nodes harvested with nodal metastases in only 14 (34%). Median FU for pts with AC was 27 mos. AC recurred in 12 pts (27%) with a 3-yr RFS of 59%. OS for pts with MCN-associated AC was 64% at 3 yrs. Conclusions: Adenocarcinoma or high grade dysplasia is present in 15% of resected pancreatic mucinous cystic neoplasms. Pre-operative factors associated with AC/HGD in an MCN include male gender, head/neck location, larger MCN, solid component/mural nodule, and duct dilation on imaging. MCN-associated AC appears to have decreased LN involvement and increased RFS and OS compared to typical pancreatic ductal adenocarcinoma. [Table: see text