University of Münster

About: University of Münster is a education organization based out in Münster, Germany. It is known for research contribution in the topics: Population & Catalysis. The organization has 35609 authors who have published 69059 publications receiving 2278534 citations. The organization is also known as: University of Munster & University of Muenster.

Accuracy of pedicle screw placement in lumbar vertebrae.

Abstract: Study design: The location of pedicle screws (n = 42) in four human specimens of the lumbar spine and in 30 patients (n = 131 screws) after lumbar spinal fusion was assessed using computed tomography. Objectives: To determine the accuracy of pedicle screw placement in lumbar vertebrae and the reproducibility and repeatability of the computed tomography examination. Summary of background data: Failures in the placement of transpedicular screws for lumbar fusion are reported. The evaluation of such screws using computed tomography examination has not been investigated. Methods: After surgery, the specimens were dissected in transversal slices to observe macroscopically the location of the pedicle screw and to correlate these observations with the computed tomography images. All patients were examined by one observer. To determine the reproducibility and repeatability of the computed tomography examination, two observers studied computed tomography images of 12 patients (n = 58 screws) twice within 3 months. Results: In the specimens, 10 screws were observed to penetrate the medial wall of the pedicle. This correlated fully with the images. In the patients' group, 40% of all screws penetrated the cortex of the vertebra. Of all screws, 29% penetrated the medial wall of the pedicle. From the computed tomography images, it appeared that a deviation of more than 6 mm medially was a high risk for nerve root damage. Three months after his first examination, Observer 1 documented a different position in three of 58 screws (kappa = 0.90). Observer 2 found a different position in eight screws (kappa = 0.65). The comparison between the reviews of the two observers showed a different opinion for the first evaluation, four disagreements (2-4 mm) and 17 disagreements (0-2 mm; kappa = 0.34), and for the second evaluation, four disagreements (2-4 mm) and 12 disagreements (0-2 mm; kappa = 0.43). Conclusions: Correct placement of transpedicular screws for spinal fusion seems to be more difficult than it looks. The computed tomography scanning is useful for differential diagnosis of postoperative radicular syndromes after lumbar transpedicular fixation.

The IASP classification of chronic pain for ICD-11: chronic neuropathic pain.

Abstract: The upcoming 11th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD) of the World Health Organization (WHO) offers a unique opportunity to improve the representation of painful disorders. For this purpose, the International Association for the Study of Pain (IASP) has convened an interdisciplinary task force of pain specialists. Here, we present the case for a reclassification of nervous system lesions or diseases associated with persistent or recurrent pain for ≥3 months. The new classification lists the most common conditions of peripheral neuropathic pain: trigeminal neuralgia, peripheral nerve injury, painful polyneuropathy, postherpetic neuralgia, and painful radiculopathy. Conditions of central neuropathic pain include pain caused by spinal cord or brain injury, poststroke pain, and pain associated with multiple sclerosis. Diseases not explicitly mentioned in the classification are captured in residual categories of ICD-11. Conditions of chronic neuropathic pain are either insufficiently defined or missing in the current version of the ICD, despite their prevalence and clinical importance. We provide the short definitions of diagnostic entities for which we submitted more detailed content models to the WHO. Definitions and content models were established in collaboration with the Classification Committee of the IASP's Neuropathic Pain Special Interest Group (NeuPSIG). Up to 10% of the general population experience neuropathic pain. The majority of these patients do not receive satisfactory relief with existing treatments. A precise classification of chronic neuropathic pain in ICD-11 is necessary to document this public health need and the therapeutic challenges related to chronic neuropathic pain.

Use of L-asparaginase in childhood ALL.

Abstract: Owing to the high efficacy of L-asparaginase in the treatment of acute lymphatic leukaemia the enzyme was introduced into the chemotherapy schedules for remission induction of this disease shortly after results of large-scale clinical trials had become available. Since asparaginase monotherapy was associated with a high response rate but short remission duration, the enzyme is currently employed within the framework of combination chemotherapy schedules which achieve treatment response in about 90% and long-term remissions in the majority of patients. Recently initiated clinical trials have still confirmed the eminent value of asparaginase in the combination chemotherapy of acute lymphatic leukaemia and of some subtypes of non-Hodgkin lymphoma, and its important role as an essential component of multimodal treatment protocols. Despite the unique mechanism of action of this cytotoxic substance which shows relative selectivity with regard to the metabolism of malignant cells, some patients experience toxic effects during asparaginase therapy. Immunological reactions toward the foreign protein include enzyme inactivation without any clinical manifestations as well as anaphylactic shock. Severe functional disorders of organ systems result from the impaired homeostasis of the amino acids asparagine and glutamine. The changes affecting the proteins of the coagulation system have considerable clinical impact as they may induce bleeding as well as thromboembolic events and may be associated with life-threatening complications when the central nervous system is involved. Risk factors predisposing to thromboembolic complications are hereditary resistance against activated protein C and any other hereditary thrombophilia. Other organ systems potentially affected by relevant functional disorders are the central nervous system, the liver, and the pancreas, with patients who have a history of pancreatic disorders carrying an especially high risk of developing pancreatitis. Studies on the mechanisms of action and the occurrence of resistance phenomena have shown that a treatment response may only be expected if the malignant cells are unable to increase their asparagine synthetase activity to an extent providing enough asparagine to the cell; one may thus conclude that the enzyme-induced asparagine depletion of the serum constitutes the decisive cytotoxic mechanism. Independent of the asparagine depletion related cytotoxicity however, there are other mechanisms of clinical relevance like induction of apoptosis. Besides this, further influences on signal transduction cannot be excluded. Only few publications have dealt with the question of minimum trough activities to be ensured before each subsequent asparaginase dose in order to maintain uninterrupted asparagine depletion under treatment, and answers to this problem are not definitive. Clinical studies using enzymes from E. coli strains indicate that a trough activity of 100 U/l will suffice for complete asparagine depletion of the fluid body compartments with the preparations studied. These findings have been transferred to enzymes from other E. coli strains as well as those isolated from Erwinia chrysanthemi and to the PEG-conjugated E. coli asparaginases. It might be desirable to countercheck the results for confirmation or correction. The dosage and administration schedule of the various enzyme preparations required for complete asparagine depletion over a period of time have been insufficiently defined. While pharmacokinetic studies showed clinically relevant differences in biological activity and activity half-lives for enzymes from different biological sources, the findings of recently published clinical trials indicate that the therapeutic efficacy is affected when different asparaginase preparations are given by identical therapy schedules. (ABSTRACT TRUNCATED)