Isolierung von freien Nucleotiden aus verschiedenen Geweben

Zusammenfassung In Erweiterung früherer Mitteilungen wird über den Gehalt des Flexner-Jobling-Carcinoms der Ratte an freien Nucleosidmono- und-polyphosphorsäureestern berichtet.Die vorliegenden Untersuchungen wurden zum Teil dankenswerter-weise durch denAnna-Fuller-Fund und dieDeutsche Forschungsgemeinschaft unterstützt.In der Arbeit werden folgenden Abkürzungen verwendet Ad Adenosin - AMP Adenosin-5-monophosphat - ADP Adenosin-5-diphosphat - ATP Adenosin-5-triphosphat - GMP Guanosin-5-monophosphat - GDP Guanosin-5-diphosphat - GTP Guanosin-5-triphosphat - CMP Cytidin-5-monophosphat - CDP Cytidin-5-diphosphat - CTP Cytidin-5-triphosphat - UMP Uridin-5-monophosphat - UDP Uridin-5-diphosphat - UTP Uridin-5-triphosphat - UDPA Uridin-5-diphosphat-N-acetylglucosamin - UDPG Uridin-5-diphosphat-glucose - UDPGa Uridin-5-diphosphat-galaktose - UDPGl Uridin-5-diphosphat-glucuronsäure - IMP Inosin-5-monophosphat - DPN Diphosphopyridinnucleotid - HS Harnsäure - RNS Ribonucleinsäure - DNS Desoxyribonucleinsäure - TPN Triphosphopyridinnucleotid Mit 19 TextabbildungenDer überwiegende Teil der dieser Arbeit zugrunde liegenden Versuche wurde 1952/53 im McArdle Memorial Laboratory, University of Wisconsin durchgeführt.     

Aggressive chemotherapy for diffuse histiocytic lymphoma in the elderly: increased complications with advancing age

Twenty patients greater than or equal to 70 years of age were included in a study of the treatment of diffuse histiocytic lymphoma utilizing cyclophosphamide, adriamycin, vincristine, and prednisone. These patients ranged in age from 70 to 94 years (median 75 years). There were also 55 younger patients (age range 33 to 69 years) in the treatment trial. There were no dose adjustments for age. The complete remission rate in the elderly patients (45 per cent) was not different from that in the younger patients (53 per cent). The overall survival in the elderly patients (median 13 months) was somewhat shorter than that in the younger patients (medians 22 months for patients 56-69 years of age and 41 months for patients 33-55 years of age), but not significantly different. Death during the first two treatment cycles from causes other than lymphoma occurred in 25 per cent of the patients greater than or equal to 70 years of age versus 2 per cent of younger patients (P less than 0.01). In addition, three other patients aged 79, 65, and 59 years died in the fourth or fifth cycles of treatment from causes other than lymphoma. Thus, 30 per cent of patients greater than or equal to 70 years of age died during therapy from causes other than lymphoma, versus 5 per cent of younger patients (P less than 0.01). Whether this altered ability to tolerate therapy in the older patients reflected decreased marrow function, altered drug metabolism, other effects of aging, or a combination of these factors is not clear. It might be appropriate to alter drug doses when treating elderly patients, and particular attention to supportive measures seems appropriate.     

Tracheal Stenosis after Tracheostomy

INTRODUCTIONTracheal stenosis is a late and usually non-life threatening complication of surgical and percutaneous tracheostomies (PDT) as well as delayed endotracheal extubation.METHODSWe undertook a retrospective review of all patients who underwent a surgical tracheostomy over a 10 year period. Patients were included in the study if they had CT or MRI imaging of the tracheostomy site both pre-operatively and six or more weeks post operatively. Patients whose imaging was not available were excluded (n = 3) as were those patients who still had a tracheostomy in situ (n = 8). In total 91 patients were included in the study. In the same period 1170 surgical tracheostomies were performed by the maxillofacial surgeons. The images were analysed by a radiologist and the degree of stenosis reported.RESULTSAll 91 patients underwent a tracheostomy with a window. 83 patients did not demonstrate any stenosis. Looking at the remaining 8 patients with stenosis: 6 patients had stenosis of less than 25%, 1 patient had stenosis between 25-50% and 1 patient had stenosis greater than 50%. Both patients with stenosis greater than 25% had more than one surgical tracheostomy.CONCULSIONWe have shown that the risk of stenosis is 8.8%, lower than often quoted in literature, and when it occurs it is likely to be symptomatic only in severe stenosis. Our main risk of stenosis was repeat surgical tracheostomies which also seems to be linked to a greater degree of stenosis.     

Host adaptation and immune modulation are mediated by homologous recombination in Helicobacter pylori

Rearrangement of genomic DNA via homologous recombination provides an alternative mechanism of gene regulation that is essential for successful colonization of the gastric mucosa by Helicobacter pylori. Inoculation of outbred mice with the H. pylori SS1 wild-type strain elicited a T helper (Th) 2 response and established a persistent infection. In contrast, inoculation with an isogenic H. pylori strain defective for homologous recombination elicited a Th1-mediated immune response and clearance of infection within 70 days. We, therefore, demonstrate that recombination is critical for mediating persistence of a microbial pathogen through the induction of ineffective immune responses.