57 results on '"Ahlers, Olaf"'
Search Results
52. The cellular and molecular basis of hyperthermia
- Author
-
Hildebrandt, Bert, Wust, Peter, Ahlers, Olaf, Dieing, Annette, Sreenivasa, Geetha, Kerner, Thoralf, Felix, Roland, and Riess, Hanno
- Subjects
- *
TREATMENT of fever , *CLINICAL trials , *RADIOTHERAPY - Abstract
In oncology, the term ‘hyperthermia’ refers to the treatment of malignant diseases by administering heat in various ways. Hyperthermia is usually applied as an adjunct to an already established treatment modality (especially radiotherapy and chemotherapy), where tumor temperatures in the range of 40–43 °C are aspired. In several clinical phase-III trials, an improvement of both local control and survival rates have been demonstrated by adding local/regional hyperthermia to radiotherapy in patients with locally advanced or recurrent superficial and pelvic tumors. In addition, interstitial hyperthermia, hyperthermic chemoperfusion, and whole-body hyperthermia (WBH) are under clinical investigation, and some positive comparative trials have already been completed. In parallel to clinical research, several aspects of heat action have been examined in numerous pre-clinical studies since the 1970s. However, an unequivocal identification of the mechanisms leading to favorable clinical results of hyperthermia have not yet been identified for various reasons. This manuscript deals with discussions concerning the direct cytotoxic effect of heat, heat-induced alterations of the tumor microenvironment, synergism of heat in conjunction with radiation and drugs, as well as, the presumed cellular effects of hyperthermia including the expression of heat-shock proteins (HSP), induction and regulation of apoptosis, signal transduction, and modulation of drug resistance by hyperthermia. [Copyright &y& Elsevier]
- Published
- 2002
- Full Text
- View/download PDF
53. The practial use of the consensus statement on practical skills in medical school--a validation study.
- Author
-
Blaum WE, Dannenberg KA, Friedrich T, Jarczewski A, Reinsch AK, and Ahlers O
- Subjects
- Clinical Clerkship, Competency-Based Education, Curriculum, Germany, Goals, Humans, Internship and Residency, Statistics as Topic, Clinical Competence standards, Consensus, Education, Medical standards
- Abstract
Objective: The importance of the acquisition of practical medical skills during medical school is increasing. With the consensus statement "Practical Skills," developed by the GMA as part of the National Competency-Based Learning Objective Catalogue for Medicine (NKLM), a reference frame was created for the procurement of such skills. This frame consists of 290 learning objectives divided by "organ system," type (core or elective learning objective), current stage of medical education and level of instruction. By comparing a large and well evaluated range of student tutorials with the consensus statement, one can analyze the practical benefit of the statement, as well as evaluate the tutorial program for completeness., Methods: In the first stage, four evaluators in two groups independently classified all consensus statement's learning objectives by each of the 48 tutorials currently offered. The inter-rater reliability among the evaluators of each group was calculated both collectively, and according to each organ system. In the second stage, disagreements in the classification were resolved through discussion and consensus decision-making. The coverage of the learning objectives by the tutorials, in the required level of instruction, was then analyzed separately by learning objective type and organ system. Reasons for any initial dissent were recorded and grouped thematically., Results: The correlation between the classifications of the two evaluators was moderately significant. The strength of this correlation, and thus the precision of individual learning goals wording, varied according to organ system. After a consensus was reached, the results show that the offered tutorials covered 66% of all learning objectives, as well as 74% of the core objectives. The degree of coverage differed according to organ system and stage of medical education., Conclusion: The consensus statement is suitable to systematically analyze and develop teaching units. The comparison with established curricula also offers possibilities for further development of the consensus statement, and therefore also of the NKLM.
- Published
- 2012
- Full Text
- View/download PDF
54. [First therapy of decompression injuries].
- Author
-
Castan J, Wirtz S, Moecke H, Schmidbauer W, Ahlers O, and Kerner T
- Subjects
- Air Pressure, Barotrauma pathology, Barotrauma physiopathology, Decompression Sickness epidemiology, Decompression Sickness history, Decompression Sickness physiopathology, Diving history, Emergency Medical Services, Germany epidemiology, History, 16th Century, History, 17th Century, History, 18th Century, History, 19th Century, History, 20th Century, Humans, Decompression Sickness therapy, Diving injuries
- Abstract
The diving accident is a rare incident for an emergency physician which requires special physical and patho-physiological knowledge. With increasing recreational activities and the fascination of diving also for older persons diving accidents are expected to occur more often. There can be several reasons for diving accidents such as the ignorance of the physics of diving, a trauma under water as well as internistical illnesses like heart attach, stroke or hypoglycaemia. The therapy of the underlying illness should not be left aside while dealing with the patient. The careful rescue and the immobilisation are most important for the initial therapy. The patient should receive oxygen, if possible via a demand valve, until a hyperbaric chamber is reached. There is no specific medical therapy for decompression illness. It is very important that a pre-information is sent to the closest hyperbaric chamber as soon as possible since often the chamber needs some time to be properly prepared for usage. In order to receive information regarding the depth where the diving incident occured, the duration of the diving trip and the decompression stops, it is important to secure the diving computer of the victim for the hyperbaric chamber. Also outside diving, decompression illness can occur, for example working in a tunnel under hyperbaric conditions. These accidents have to be treated according to the same guidelines., (Georg Thieme Verlag Stuttgart * New York.)
- Published
- 2010
- Full Text
- View/download PDF
55. Combined vs. Isoflurane/Fentanyl anesthesia for major abdominal surgery: Effects on hormones and hemodynamics.
- Author
-
Goldmann A, Hoehne C, Fritz GA, Unger J, Ahlers O, Nachtigall I, and Boemke W
- Subjects
- Adult, Aged, Angiotensin II blood, Blood Glucose drug effects, Blood Pressure drug effects, Drug Therapy, Combination, Endothelin-1 blood, Epinephrine blood, Female, Heart Rate drug effects, Humans, Hydrocortisone blood, Male, Middle Aged, Osmolar Concentration, Plasma chemistry, Prospective Studies, Sodium blood, Vasoconstrictor Agents metabolism, Abdomen surgery, Anesthesia, Epidural, Anesthesia, General, Fentanyl pharmacology, Hemodynamics drug effects, Isoflurane pharmacology, Plasma drug effects
- Abstract
Background: Combination of epidural and general anesthesia (combined anesthesia) avoids the intraoperative use of intravenous analgesics and may reduce the surgical stress response during major abdominal surgery. This study examines the differences in intraoperative hemodynamic stability, cortisol levels and activity of cardiovascular hormones between combined anesthesia and isoflurane/fentanyl anesthesia., Material/methods: Sixty ASA I-II patients were prospectively randomized to receive either combined anesthesia, i.e, isoflurane anesthesia combined with thoracic epidural analgesia (bolus of 12 ml 0.2% ropivacaine containing 1 microg/ml sufentanil 30 min before incision, followed by continuous infusion at 6 ml/h) or isoflurane/fentanyl anesthesia (IV fentanyl as required) for major abdominal surgery. Depth of anesthesia was monitored using Bispectral Index. Administration of fluids and of vasopressors was directed by a standardized protocol. Blood samples for angiotensin II, vasopressin, catecholamines, and cortisol were drawn before anesthesia, after induction (but before using the epidural catheter), and 40 min after skin incision., Results: After induction of anesthesia, mean arterial pressure decreased by 12-20 mmHg in both groups and angiotensin-II concentrations increased. Vasopressin increased predominantly after opening the abdomen in both groups. Under combined anesthesia, intraoperative epinephrine and cortisol concentrations were considerably lower. Intraoperative crystalloid fluid substitution, blood loss and urine output did not differ between groups. There were more hypotensive periods and the demand for colloids and low-dose continuous norepinephrine was greater under combined anesthesia., Conclusions: Combined anesthesia reduces the intraoperative stress response, but moderate hemodynamic instability is relatively common and has to be compensated for by adequate volume replacement and vasopressor support.
- Published
- 2008
56. Intraoperative fresh-frozen plasma versus human albumin in craniofacial surgery--a pilot study comparing coagulation profiles in infants younger than 12 months.
- Author
-
Hildebrandt B, Machotta A, Riess H, Kerner S, Ahlers O, Haberl H, Dörken B, and Kerner T
- Subjects
- Biomarkers blood, Craniofacial Abnormalities surgery, Erythrocyte Transfusion, Female, Fibrinolysis drug effects, Humans, Infant, Male, Partial Thromboplastin Time, Pilot Projects, Specialties, Surgical methods, Albumins administration & dosage, Blood Coagulation drug effects, Craniosynostoses surgery, Intraoperative Care methods, Plasma Exchange
- Abstract
The transfusion of fresh-frozen plasma (FFP) is suggested to minimize dilution coagulopathy when applied instead of colloids during paediatric craniofacial surgery (pCFS). We prospectively compared plasmatic haemostaseologic function between volume replacement with FFPs versus human albumin (HA) in a pilot study. Thirty infants with primary craniosynostosis were scheduled for pCFS. In 15 of those, FFPs were available from the identical donor as for packed red blood cells (pRBC), and were thus employed for intraoperative volume replacement. The remaining 15 infants were infused with HA-5% instead. Haemoglobin(Hb)-values, global coagulation parameters (activated partial thromboplastin time-aPTT; prothrombin time-PT), selected clotting factors (F) (VIII, XI, XIII), antithrombin-AT, fibrinolytic factors (fibrinogen; plasminogen; alpha2-antiplasmin-alpha2A), and activation parameters (thrombin-antithrombin-complex-TAT; plasmin-antiplasmin-complex-PAP; D-dimers) were assessed and compared between both groups after induction of anaesthesia, before transfusion of pRBC, and at the end of surgery. Patients and treatment characteristics were balanced between both groups. Prolongation of aPTT and decreases of PT, FXI, FXIII, AT3, and fibrinolytic factors were more pronounced in the HA-group. Increases in F VIII activity, activation parameters, and the course of Hb-values were similar among both groups. There was no difference regarding clinical endpoints (peri-/postoperative pRBC-transfusions, postoperative blood loss). In conclusion, the application of HA was associated with a more distinct dilution of procoagulant factors, AT3, and fibrinolytic factors than the use of FFPs. However, the course of activation markers suggested a similar extent of clotting and fibrinolytic activation with the use of both transfusion regimens, and there were no differences with regard to clinical endpoints.
- Published
- 2007
57. The effect of induced hyperthermia on the immune system.
- Author
-
Dieing A, Ahlers O, Hildebrandt B, Kerner T, Tamm I, Possinger K, and Wust P
- Subjects
- Animals, Humans, Neoplasms immunology, Neoplasms therapy, Hyperthermia, Induced methods, Immune System physiology
- Abstract
Therapeutical hyperthermia has been considered for cancer therapy since William Coley observed tumour remission after induction of fever by bacterial toxins at the end of the 19th century. Because fever is associated with a variety of immunological reactions, it has been suspected, that therapeutical hyperthermia might also activate the immune system in a reproducible manner and thereby positively influence the course of the disease. During the last decade, new insight has been gained regarding the immunological changes taking place during therapeutic hyperthermia. In this chapter, we review the most relevant data known about the effect of hyperthermia on the immune system with special focus on alterations induced by therapeutical whole-body hyperthermia (WBH) in cancer patients.
- Published
- 2007
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.