Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

We review HB stars in a broad astrophysical context, including both variable and non-variable stars. A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics. We show that the Oosterhoff dichotomy and the distribution of globular clusters (GCs) in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the second-parameter problem is presented. A technique is proposed to estimate the HB types of extragalactic GCs on the basis of integrated far-UV photometry. The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyrae, is also revisited, giving a distance modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are studied. Finally, the conductive opacities used in evolutionary calculations of low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and Space Scienc

Diagnosis and treatment of pancreatic duct disruption or disconnection: an international expert survey and case vignette study

Background: Pancreatic duct disruption or disconnection is a potentially severe complication of necrotizing pancreatitis. With no existing treatment guidelines, it is unclear whether there is any consensus among experts in clinical practice. We evaluated current expert opinion regarding the diagnosis and treatment of pancreatic duct disruption and disconnection in an international case vignette study. Methods: An online case vignette survey was sent to 110 international expert pancreatologists. Expert selection was based on publications in the last 5 years and/or participation in development of IAP/APA and ESGE guidelines on acute pancreatitis. Consensus was defined as agreement by at least 75% of the experts. Results: The response rate was 51% (n = 56). Forty-four experts (79%) obtained a MRI/MRCP and 52 experts (93%) measured amylase levels in percutaneous drain fluid to evaluate pancreatic duct integrity. The majority of experts favored endoscopic transluminal drainage for infected (peri)pancreatic necrosis and pancreatic duct disruption (84%, n = 45) or disconnection (88%, n = 43). Consensus was lacking regarding the treatment of patients with persistent percutaneous drain production, and with persistent sterile necrosis. Conclusion: This international survey of experts demonstrates that there are many areas for which no consensus existed, providing clear focus for future investigation

Potential target antigens for immunotherapy in human pancreatic cancer.

BACKGROUND: To be effective and selective, immunotherapy ideally targets specifically tumor cells and spares normal tissues. Identification of tumor specific antigens is a prerequisite to establish an effective immunotherapy. Still very little is known about the expression of tumor-related antigens in pancreatic neoplasms. Cancer Testis antigens (CT) are antigens shared by a variety of malignant tumors, but not by normal tissues with the exception of germ cells in testis. Restricted expression in neoplastic tissues and inherent immunogenic features make CT antigens ideal for use in immunotherapy. We analyzed the expression of a selected panel of nine CT antigens that have been proven to elicit an efficient immunogenic response in other malignancies. In addition we analyzed the expression of HERV-K-MEL, an immunogenic antigen of viral origin. METHODS: Pancreatic adenocarcinoma tumor samples (n=130) were obtained intraoperatively, control tissues (n=23) were collected from cadaveric donor and from patients with chronic pancreatitis. Tumor-associated antigen expression of MAGE-A1, MAGE-A3, MAGE-A4, MAGE-A10, LAGE-1, NY-ESO-1, SCP-1, SSX-2, SSX-4 and HERV-K-MEL was assessed by PCR. Sequencing of PCR products were performed to assess the expression of SSX-4 in neoplastic and normal pancreatic tissues. RESULTS: Three of 10 tested antigens were expressed in over 10% of malignant pancreatic tissue samples. SSX-4 was found positive in 30% of cases, SCP-1 in 19% and HERV-K-MEL in 23% of cases. No expression of CT antigens was found in non-malignant pancreatic tissue with the exception of SSX-4 and and SSX-2. CONCLUSIONS: Fifty two percentage of the analyzed tissues expressed at least one CT antigen. The concomitant expression of SSX-4 in both malignant and non-malignant pancreatic tissue is a new finding which may raise concerns for immunotherapy. However, HERV-K-MEL is expressed with a relatively high prevalence and may be a candidate for specific immunotherapy in a large subgroup of pancreatic cancer patients. This study advocates the analysis of patients with regard to their immunogenic profile before the onset of antigen-specific immunotherapy

RESULTS OF EUROPEAN POOLED ANALYSIS OF IORT CONTAINING MULTIMODALITY TREATMENT FOR LOCALLY ADVANCED RECTAL CANCER: ADJUVANT CHEMOTHERAPY PREVENTS LOCAL RECURRENCE RATHER THAN DISTANT METASTASES

Surgical oncolog

Results of European pooled analysis of IORT-containing multimodality treatment for locally advanced rectal cancer: adjuvant chemotherapy prevents local recurrence rather than distant metastases

Background: The purpose of this study is to analyze the pooled results of multimodality treatment of locally advanced rectal cancer (LARC) in four major treatment centers with particular expertise in intraoperative radiotherapy (IORT). Patients and methods: A total of 605 patients with LARC who underwent multimodality treatment up to 2005 were studied. The basic treatment principle was preoperative (chemo) radiotherapy, intended radical surgery, IORT and elective adjuvant chemotherapy (aCT). In uni- and multivariate analyses, risk factors for local recurrence (LR), distant metastases (DM) and overall survival (OS) were studied. Results: Chemoradiotherapy lead to more downstaging and complete remissions than radiotherapy alone (P < 0.001). In all, 42% of the patients received aCT, independent of tumor-node-metastasis stage or radicality of the resection. LR rate, DM rate and OS were 12.0%, 29.2% and 67.1%, respectively. Risk factors associated with LR were no downstaging, lymph node (LN) positivity, margin involvement and no postoperative chemotherapy. Male gender, preoperatively staged T4 disease, no downstaging, LN positivity and margin involvement were associated with a higher risk for DM. A risk model was created to determine a prognostic index for individual patients with LARC. Conclusions: Overall oncological results after multimodality treatment of LARC are promising. Adding aCT to the treatment can possibly improve LR rates.Surgical oncolog

Definition and grading of anastomotic leakage following anterior resection of the rectum: A proposal by the International Study Group of Rectal Cancer

Background. Anastomotic leakage represents a major complication after anterior resection of the rectum. The incidence of anastomotic leakage varies considerably among clinical studies in part owing to the lack of a standardized definition of this complication. The aim of the present article was to propose a definition and severity grading of anastomotic leakage after anterior rectal resection. Methods. After a literature review a consensus definition, and severity grading of anastomotic leakage was developed within the International Study Group of Rectal Cancer Results. Anastomotic leakage should, be defined as a defect of the intestinal wall at the anastomotic site (including suture and staple lines of neorectal reservoirs) leading to a communication between the intra- and extraluminal compartments. Severity of anastomotic leakage should be graded according to the impact on clinical management. Grade A anastomotic leakage results in no change in patients' management, whereas grade B leakage requires active therapeutic intervention but is manageable without re-laparotomy. Grade C anastomotic leakage requires re-laparotomy. Conclusion. The proposed definition and clinical grading is applicable easily in the setting of clinical studies. It should be applied in future reports to facilitate valid comparison, of the results of different studies. (Surgery 2010;147:339-51.)Surgical oncolog