Perioperative risk of pancreatic head resection-nomogram-based prediction of severe postoperative complications as a decisional aid for clinical practice.

PURPOSE: To develop nomograms for pre- and early-postoperative risk assessment of patients undergoing pancreatic head resection. METHODS: Clinical data from 956 patients were collected in a prospectively maintained database. A test (n = 772) and a validation cohort (n = 184) were randomly generated. Uni- and multi-variate analysis and nomogram construction were performed to predict severe postoperative complications (Clavien-Dindo Grades III-V) in the test cohort. External validation was performed with the validation cohort. RESULTS: We identified ASA score, indication for surgery, body mass index (BMI), preoperative white blood cell (WBC) count, and preoperative alkaline phosphatase as preoperative factors associated with an increased perioperative risk for complications. Additionally to ASA score, BMI, indication for surgery, and the preoperative alkaline phosphatase, the following postoperative parameters were identified as risk factors in the early postoperative setting: the need for intraoperative blood transfusion, operation time, maximum WBC on postoperative day (POD) 1-3, and maximum serum amylase on POD 1-3. Two nomograms were developed on the basis of these risk factors and showed accurate risk estimation for severe postoperative complications (ROC-AUC-values for Grades III-V-preoperative nomogram: 0.673 (95%, CI: 0.626-0.721); postoperative nomogram: 0.734 (95%, CI: 0.691-0.778); each p ≤ 0.001). Validation yielded ROC-AUC-values for Grades III-V-preoperative nomogram of 0.676 (95%, CI: 0.586-0.766) and postoperative nomogram of 0.677 (95%, CI: 0.591-0.762); each p = 0.001. CONCLUSION: Easy-to-use nomograms for risk estimation in the pre- and early-postoperative setting were developed. Accurate risk estimation can support the decisional process, especially for IPMN-patients with an increased perioperative risk.

Clinical course and pancreas parenchyma sparing surgical treatment of severe pancreatic trauma.

INTRODUCTION: Pancreatic trauma (PT) involving the main pancreatic duct is rare, but represents a challenging clinical problem with relevant morbidity and mortality. It is generally classified according to the American Association for the Surgery of Trauma (AAST) and often presents as concomitant injury in blunt or penetrating abdominal trauma. Diagnosis may be delayed because of a lack of clinical or radiological manifestation. Treatment options for main pancreatic duct injuries comprise highly complex surgical procedures. PATIENTS AND METHODS: We retrospectively analyzed clinical data from 12 patients who underwent surgery in two tertiary centers in Germany during 2003-2016 for grade III-V PT with affection of the main pancreatic duct, according to the AAST classification. RESULTS: The median age was 23 (range: 7-44) years. In nine patients blunt abdominal trauma was the reason for PT, whereas penetrating trauma only occurred in three patients. MRI outperformed classical trauma CT imaging with regard to detection of duct involvement. Complex procedures as i.e. an emergency pancreatic head resection, distal pancreatectomy or parenchyma sparing pancreatogastrostomy were performed. Compared to elective pancreatic surgery the complication rate in the emergency setting was higher. Yet, parenchyma-sparing procedures demonstrated safety. CONCLUSIONS: Often extension of diagnostics including MRI and/or ERP at an early stage is necessary to guide clinical decision-making. If, due to main duct injuries, surgical therapy for PT is required, we suggest consideration of an organ preservative pancreatogastrostomy in grade III/IV trauma of the pancreatic body or tail.

[Computer-controlled high-precision radiation]. / Computergesteuerte Hochpräzisionsbestrahlung.

The irradiation of tumors in the brain is challenging due to the proximity of radiation sensitive critical structures and the tumors to be treated. In addition, irradiation above a certain level can cause irreversible damage to nerve tissue. The irradiation of benign and malignant brain tumors requires precise techniques to preserve critical structures while simultaneously administering a high radiation dose for maximum effectiveness. Therefore, stereotaxy, as a subspecialty of neurosurgery, has developed various irradiation techniques, e. g., intracerebral application of interstitial brachytherapy (SBT; stereotactic brachytherapy) and stereotactic radiosurgery (SRS). Due to the development of computer-controlled radiation techniques (e. g., Cyberknife) over the last 20 years, SRS has gained increasing importance.

Kinetic mechanism of Ca²âº-controlled changes of skeletal troponin I in psoas myofibrils.

Conformational changes in the skeletal troponin complex (sTn) induced by rapidly increasing or decreasing the [Ca(2+)] were probed by 5-iodoacetamidofluorescein covalently bound to Cys-133 of skeletal troponin I (sTnI). Kinetics of conformational changes was determined for the isolated complex and after incorporating the complex into rabbit psoas myofibrils. Isolated and incorporated sTn exhibited biphasic Ca(2+)-activation kinetics. Whereas the fast phase (k(obs)∼1000 s(-1)) is only observed in this study, where kinetics were induced by Ca(2+), the slower phase resembles the monophasic kinetics of sTnI switching observed in another study (Brenner and Chalovich. 1999. Biophys. J. 77:2692-2708) that investigated the sTnI switching induced by releasing the feedback of force-generating cross-bridges on thin filament activation. Therefore, the slower conformational change likely reflects the sTnI switch that regulates force development. Modeling reveals that the fast conformational change can occur after the first Ca(2+) ion binds to skeletal troponin C (sTnC), whereas the slower change requires Ca(2+) binding to both regulatory sites of sTnC. Incorporating sTn into myofibrils increased the off-rate and lowered the Ca(2+) sensitivity of sTnI switching. Comparison of switch-off kinetics with myofibril force relaxation kinetics measured in a mechanical setup indicates that sTnI switching might limit the rate of fast skeletal muscle relaxation.

Wild-type p53 is not involved in reversion of the tumorigenic phenotype of breast-cancer cells after transfer of normal chromosome-17.

A number of different candidate tumor suppressor genes involved in human breast cancer are presumed to be located on chromosome 17. To verify the relevance of chromosome 17 abnormalities in breast cancer cells, a normal human chromosome 17 was transferred by microcell fusion to R30 tumor cells derived from an infiltrating ductal mammary carcinoma. The tumorigenicity of the microcell hybrids in nude mice was examined. The tumor volume obtained with different clones was reduced by up to 94% of the value corresponding to the parental tumor cells. This effect was accompanied by a reduction of anchorage-independent growth, as well as cell growth rates on plastic plates. These effects were independent of the continued presence of a transferred 17q arm and could not be attributed to the action of the normal p53 gene. The results support the assumption that in addition to p53 a further tumor suppressor gene is located on 17p which is involved in breast cancer.

HeLa D98/aH-2 studied by chromosome painting and conventional cytogenetical techniques.

Metaphase chromosomes of HeLa D98/AH-2 cells were studied by GTG-banding, NOR-silver staining and in situ hybridization using libraries specific for each human chromosome as probes (chromosome painting). The structure and composition of all marker chromosomes could be determined, allowing a critical assessment of earlier studies. The revised HeLa D98/AH-2 karyotype should provide a reference standard in certain cancer cytogenetic studies.

Neutrophil elastase and acute pulmonary damage in neonates with severe respiratory distress syndrome.

This study evaluated possible acute effects of neutrophil elastase on neonatal pulmonary morbidity. The activity of free elastase and alpha 1-proteinase inhibitor as well as concentrations of elastase-alpha 1-proteinase inhibitor in tracheal aspirate fluid of neonates with severe respiratory distress syndrome (fraction of inspired oxygen > 0.6, mechanical ventilation) were analyzed between 6 and 36 hours after surfactant replacement therapy. One hundred forty neonates were included in this prospective study. Characteristics, disease severity, and ventilatory requirements were nearly identical in both groups. All patients were treated with natural porcine surfactant (Curosurf) at an age of 2 to 15 hours. In 42 neonates (30%) considerable activities of free elastase were detected (805 micrograms/L; 100 to 1850 [median, 25th to 75th percentile]); in 98 neonates (70%) who had protective levels of alpha 1-proteinase inhibitor, no elastase activity was detected. The average concentrations of elastase-alpha 1-proteinase inhibitor were significantly increased in patients with free elastase activity when compared with those of the nonelastase group. In logistic regression analyses, 28-day outcome data showed a pronounced increase in risk of pulmonary interstitial emphysema for patients with free elastase activity in tracheal aspirate fluid. The incidence of other pulmonary and nonpulmonary complications was very similar in both groups. It is concluded that elastolytic damage and barotrauma may both contribute to acute pulmonary injury in the early stages of respiratory distress syndrome.

A computer-based frozen blood inventory and information system.

A computer-based, time-sharing data processing system was developed to assist in maintaining information regarding units of red blood cells frozen for eventual transfusion. An automated system has been programmed to compile and retrieve data concerning stored units, prepare shipping documents as required, and maintain transfusion records in a retrievable manner for thawed or shipped units. Requests for frozen red blood cells are processed through this system. Units are selected by the computer to meet requirements specified by the operator of a keyboard terminal. These requirements include method of cryopreservation, specific antigenic characteristics required, and the number of units requested. The computer prints out on the keyboard terminal the units meeting the requirements and the keyboard operator then indicates to the computer the name of the requesting facility, if these units are to be shipped. This input initiates a programmed routine that generates a shipping invoice and a new file for these units in a permanent transfusion record which can by acessed by either donor number or the frozen blood cell code.