Über die Bedingungen des Eintrittes der Totenstarre beim gereizten Muskel

Zusammenfassung Es wird gezeigt, daß das Nichteintreten der Totenstarre in einer Gasatmosphäre bei bis zur Erschöpfung gereizten Froschmuskeln in hohem Maße abhängig ist von genügender Sauerstoffzufuhr zu allen Teilen.Beim dünnen M. sartorius genügt der Sauerstoff der Luft. Beim M. gastrocnemius ist es auch durch Sauerstoffüberdruck nicht möglich, den Eintritt der Starre nach Reizung zu verhindern. Erst durch gleichzeitiges Eintauchenlassen in Flüssigkeit wird dieser Zweck erfüllt.Bei Aufbewahrung inFlüssigkeit genügt für den M. sartorius im allgemeinen die Unterbringung in selbst O₂-armer (ausgekochter) Ringerlösung zur Verhütung von Starre nach erschöpfender Reizung. Nachträgliches Durchleiten von Wasserstoff oder Stickstoff ruft Contractur hervor. Bei M. gastrocnemius genügt einfaches Unterbringen in Lösung nicht, erst bei Sauerstoffdurchleitung oder bei gleichzeitigem Sauerstoffüberdruck läßt sich Starre vermeiden.Durchleiten eines indifferenten Gasesvor Beginn der Reizung führt zu einer sehr raschen Erschöpfbarkeit des Muskels ohne Starre.Auch beimWarmblütermuskel gelingt es in vielen Fällen trotz erschöpfender Reizung den Starreeintritt zu verhindern, jedoch nur bei dünnen, ungeschädigten Muskeln, unter Sauerstoffüberdruck und in einem flüssigen Medium.Die Untersuchungen bestätigen durchaus die Auffassung, daß die Totenstarre eine Folge der Anhäufung von Milchsäure ist. Die Wegschaffung der letzteren durch Diffusion und Oxydation verhindert den Starreeintritt.Zum Schlusse möchte ich Herrrn ProfessorWinterstein auch an dieser Stelle meinen herzlichsten Dank aussprechen für die dauernde Unterstützung und Förderung bei vorliegender Arbeit.     

Fractures of the clivus: classification and clinical features

Fractures of the clival complex were diagnosed in a series of 17 patients admitted to the Maryland Institute for Emergency Medical Services System and the University of Maryland Medical System over a 30-month period. These fractures were divided pathologically into three types based upon their appearance on computed tomography: longitudinal, transverse, and oblique. The mechanisms of injury were similar in all groups, and the Glasgow Coma Scale scores at admission were comparable, regardless of fracture type, in survivors and nonsurvivors. Longitudinal fractures were associated with severe injury to the central nervous system and with brain stem infarction, and 4 of 6 (67%) of these patients died. Transverse fractures of the clival complex were found in 6 patients, 3 of whom (50%) died. All of these patients had fractures of the petrous ridge; 2 of the 3 survivors had multiple cranial nerve deficits, and one patient developed a carotid-cavernous fistula. Of the 5 patients with oblique clival fractures, 2 survived (40%), both of whom had multiple cranial nerve palsies; in addition, one of these patients developed a carotid-cavernous fistula. Using the present generation of computed tomographic scanners, fractures of the clival complex can be reliably diagnosed; they are probably more common than previously believed and can be separated into three groups based on the characteristics on computed tomographic scans and clinical findings.     

Treatment selection for carcinoma of the base of the tongue

Between 1974 and 1984, 173 patients were treated for squamous cell carcinoma of the tongue base. Fifty-four patients had T1 or T2 primaries, while 115 patients had T3 or T4 tumors (4 were not staged). Lymph node metastasis was present in 120 patients. Early primary tumors treated with surgery or radiotherapy had a control rate of 83% (5 of 6 tumors) and 89% (40 of 45 tumors), respectively. For advanced primary tumors, definitive radiotherapy produced a local control rate of 55% (42 of 76 tumors), compared with 79% (23 of 29 tumors) for surgery and postoperative radiotherapy. If primary control was obtained, the regional failure rate was less than 10%. Tumor growth patterns were predictive of the response to radiotherapy. The primary control rate at 2 years for 21 patients with exophytic tumors was 84% as opposed to 58% for 62 patients with ulcerative-infiltrative tumors (p = 0.04). Radiotherapy is effective for early stage or exophytic tumors, whereas for advanced or deeply invasive tumors combined therapy enhances local control.     

Expression and distribution of vascular endothelial growth factor protein in human brain tumors

Marked neovascularization is a hallmark of many neoplasms in the nervous system. Recent reports indicate that the endothelial mitogen vascular endothelial growth factor (VEGF) may play a critical role in the regulation of vascular endothelial proliferation in malignant gliomas. Using novel monoclonal antibodies to the VEGF polypeptide we have determined the expression and cellular distribution of VEGF protein in a representative series of 171 human central nervous system (CNS) tumors by immunohistochemistry and immunoblotting. In agreement with previous in situ hybridization data, 19 out of 20 glioblastomas (95%) showed immunoreactivity for VEGF, whereas both the percentage of immunoreactive tumors and the extent of immunoreactivity for VEGF were significantly lower in astrocytomas. Of the pilocytic astrocytomas (WHO grade I) 44% were immunoreactive for VEGF, but we observed several cases with pronounced vascular proliferates in the absence of VEGF. In ependymomas, meningiomas, hemangioblastomas, and primitive neuroectodermal tumors, there was no correlation between VEGF expression, vascular endothelial proliferation and the grade of malignancy. Oligodendrogliomas and the oligodendroglial component of mixed gliomas lacked immunoreactive VEGF, indicating that endothelial growth factors other than VEGF may regulate tumor angiogenesis in these neoplasms. Western blot analysis showed a predominant VEGF protein species of 23 kDa and confirmed the immunohistochemical data in all cases. Our findings demonstrate that VEGF is expressed in a wide spectrum of brain tumors in which it may induce neovascularization. However, other angiogenic factors also appear to contribute to the vascularization of CNS neoplasms. Received: 18 April 1996 / Revised, accepted: 20 August 1996     

Platelet Aggregation Inhibiting and Anticoagulant Effects of Oligoamines,XXX: Absorption,Organ Distribution,and Excretion of the Oligoamine (+)-(S,S)-1,4-Bis-[4-(3-iodo-4-methoxyphenyl)-butylamino]-butane-2,3-diol and its Metabolites

The pharmacokinetic behaviour of the 131-iodine-labelled title compound 3 * and its metabolites in mice was investigated. A two phase, 1st order elimination profile was observed. The second phase is very slow leaving about 35% of radioactivity in the mice even 100h after i.v. injection, because of high affinity to liver and spleen, caused by strong binding of oligoamines to phospholipids of liver and blood cell membranes. The blood-brain-barrier is not passed. No deep compartments were observed. The doses necessary for antithrombotic effects in vivo were calculated from the blood levels to be 20.5–39.7 μmol/kg for a time interval of 1–6 h after administration.     

In vivo carbon monoxide exposure and hypoxic hypoxia stimulate immediate early gene expression

 This study aimed to examine the influence of acute tissue hypoxygenation on the expression of immediate early genes in different rat tissues. To this end male Sprague-Dawley rats were exposed to 0.1% carbon monoxide for 0.5, 1 and 6 h or to 9% oxygen for 6 h and mRNA levels for c-jun, c-fos, c-myc and EGR-1 were assayed by RNase protection in hearts, kidneys, livers and lungs. We found that hypoxia increased c-jun mRNA levels between twofold (lung) and eightfold (liver) in all organs examined; c-fos mRNA increased between threefold (lung) and 20-fold (heart); c-myc mRNA increased between twofold (lung) and sixfold (heart); and EGR-1 mRNA increased between twofold (lung) and sixfold (heart). Our findings suggest that acute tissue hypoxygenation is a general stimulus of the expression of immediate early genes in vivo. With regard to the sensitivity to hypoxia, organ differences appear to exist in that the lung is rather insensitive, whilst the heart is rather sensitive. Received: 25 February 1997 / Received after revision: 17 June 1997 / Accepted: 19 June 1997     

Inhibition of homotypic aggregation of a human Burkitt-lymphoma cell line

The molecules involved in homotypic aggregation of the human Burkitt-lymphoma cell line Raji were investigated by inhibition of reaggregation with carbohydrates and glycoconjugates, by inhibition of glycosylation, and enzyme treatment of the cell surface. Complete inhibition of reaggregation was achieved with bovine submaxillary mucin. Asialomucin, on the other hand, was not effective in this assay. Another potent inhibitor of reaggregation was the ganglioside GMI. The common carbohydrate structure of these molecules is NeuNAc-(gal)-galNAc. Lactosamine, fucosyllactosamine, sialyllactosamine, complex mannose type, or Thomsen-Friedenreich antigen sequences are not involved in aggregation. Neuraminidase and chloroquine also abolished agglutination of cells. The finding that mucin, but not asialomucin, inhibits the reaction, demonstrates the importance of sialic acid in this process. Homotypic aggregation was shown to be resistant to trypsin. Using the glycosylation inhibitor tunicamycin we show that N-glycosidically linked carbohydrate chains are involved in aggregation. Swainsonine or castanospermine, which inhibit processing of terminal sialyllactosamines to the mannose core, did not interfere with the reaction supporting the results of the inhibition assay. The data presented suggest the involvement of 2 molecules in homotypic aggregation of human Burkitt-lymphoma cells. One component is a lectin-like molecule containing N-linked carbohydrate chains. The other component carries the neuraminidase-sensitive and trypsin-resistant determinant NeuNAc-(gal)-galNAc and, therefore, appears to be a glycolipid. This proposed lectin-carbohydrate interaction in homotypic aggregation is further supported by the frequently observed dependence of lectins on divalent cations as indicated by inhibition of aggregation with EDTA and EGTA.     

Health Care Reform and the Future of Physician Ethics

Health care reform proposals threaten to exacerbate tensions physicians already face in trying to balance traditional duties to individual patients against increasing pressure to serve broader societal and institutional goals. To cope with reform, medical ethics must clarify physicians' moral obligations, change existing ethical codes, and develop an ethics of institutions.     

Development of a new dynamic method for quantitative evaluation of in vitro hemocompatibility of biomedical materials.

In this study a new dynamic method is introduced allowing the estimation of blood cell adhesion on flat test surfaces by measuring the cell loss in the bulk phase of surface contacting test blood under defined rheological conditions. This was achieved by constructing a novel test chamber permitting the contact of small amounts of blood with a large geometrical test surface. The construction consists of a spiral-shaped flow channel of 0.3 cm width, 0.02 cm height and 78 cm length covered with the biomaterials to be tested from both sides. Laminarity of blood flow in the conduit was confirmed theoretically by the calculation of an equivalent to the Reynolds number for curved systems the so-called Dean number. Furthermore, flow laminarity was proved experimentally finding that the flow rate of blood with different hematocrit values was proportional to the hydrostatic pressure applied. The applicability of the novel 'spiral method' for the estimation of hemocompatibility was demonstrated by evaluation of platelet adhesion onto different polymers in comparison to siliconized and fibrinogen coated glass as reference surfaces. Additionally, it was possible under distinct conditions to determine the adhesion of leucocytes and the detachment of platelet aggregates. Therefore, it was concluded that the spiral method can be used for the assessment of the hemocompatibility of flat biomedical polymers. As main advantages of the new method can be considered the high time efficiency and accuracy without labelling or optical detection of adherent cells.