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31.
32.
Ian Gravenor Trudy L. Norton Pamela Ritchie Emma Flint John D. Norton 《Developmental and comparative immunology》1995,19(6):507-523
Recently generated anti-Xenopus T cell monoclonal antibodies (mAbs) to the 120 kDA XTLA-1 determinant and against the putative CD5 and CD8 homologues, together with anti-IgM and anti-MHC class II mAbs, are used in dual colour flow cytometric experiments to characterize cell surface antigenic expression on lymphocytes in thymus and spleen of Xenopus laevis during larval and early adult life and also in metamorphosis-inhibited animals. Histological confirmation of T cell emergence early in larval ontogeny is supplied by cryostat sections stained for CD8. Five-day thymectomy i.e. prior to T-lineage cell differentiation in the thymus, abolishes T cell marker expression in the spleen for up to 1 year. Moreover, late larval (20 days) or early adult (3 months) thymectomy (i.e. removal after peripheralization of T cells has occurred) also leads to severe depletion of mAb-defined T cells in the spleen. 相似文献
33.
Effects of age and age-related hearing loss on the neural representation of speech cues. 总被引:6,自引:0,他引:6
OBJECTIVE: To examine the effects of aging and age-related hearing loss on the perception and neural representation of a time-varying speech cue. METHODS: P1, N1 and P2 cortical responses were recorded from younger and older normal-hearing adults, as well as older adults with age-related hearing loss. Synthetic speech tokens representing 10 ms increments along a /ba/-/pa/ voice-onset-time (VOT) continuum were used to evoke the responses. Each participant's ability to discriminate the speech tokens was also assessed. RESULTS: Compared with younger participants, older adults with and without hearing loss had more difficulty discriminating 10 ms VOT contrasts. In addition, both older groups elicited abnormal neural response patterns. There were no significant age-related findings for P1 latency; however, N1 latencies were prolonged for both older groups in response to stimuli with increased VOT durations. Also, P2 latencies were delayed for both older groups. The presence of age-related hearing loss resulted in a significant increase in N1 amplitude in response to voiceless stimuli. CONCLUSIONS: Aging and age-related hearing loss alter temporal response properties in the central auditory system. Because both older groups had difficulty discriminating these same speech stimuli, we conclude that some of the perceptual difficulties described by older adults might be due to age-related changes regulating excitatory and inhibitory processes. SIGNIFICANCE: Some of the speech understanding difficulties expressed by elderly adults may be related to impaired temporal precision in the aging auditory system. This might explain why older adults frequently complain that wearing a hearing aid makes speech louder, but does not necessarily improve their ability to understand speech. 相似文献
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36.
Ph.D. M.D.Pamela Ely M.D.Jordan Dunitz Pharm.D.John Rogosheske M.D.Daniel Weisdorf 《The American journal of medicine》1991,90(6):707-710
PURPOSE: Because the secretory diarrhea of acute graft-versus-host disease (GvHD) of the gut induces serious metabolic and nutritional disturbances, this study was initiated to assess the use of a somatostatin analogue, octreotide acetate, as adjunctive therapy for severe GvHD of the gut with massive diarrhea. PATIENTS AND METHODS: In a pilot study, six patients with biopsy-confirmed acute gut GvHD after allogeneic bone marrow transplantation received octreotide 50 to 250 micrograms three times a day subcutaneously. RESULTS: Three of the six treated patients had a prompt and dramatic reduction in stool volume within 1 to 3 days of initiation of octreotide therapy. CONCLUSIONS: Somatostatin and its analogues have been used successfully in diarrheal states by antagonism of neuropeptide overproduction, although other potential therapeutic mechanisms include inhibition of fluid secretion, enhanced salt absorption, and inhibition of gut motility. Somatostatin and its analogues may be promising adjunctive agents in the treatment of gastrointestinal GvHD, although assessment in a controlled trial will be required to confirm their therapeutic efficacy. 相似文献
37.
R. C. Fader Pamela J. Hals F. C. W. Koo 《Burns : journal of the International Society for Burn Injuries》1987,13(6):462-468
Culture filtrates of Staphylococcus aureus strains isolated from burn patients were examined for cytotoxic activities. A large molecular weight cytotoxin (MW=253000 daltons) that exhibited cytotoxicity for human foreskin cells and haemolytic activity against human and rabbit erythrocytes was identified. The cytotoxic activity could be completely neutralized by antiserum formed against the cytotoxin. Further characterization of the molecule by isoelectric focusing revealed that the cytotoxin was composed of at least two toxic factors of smaller molecular weight. Both factors exhibited cytotoxicity to tissue-culture cells. however, one factor lysed rabbit but not human erythrocytes whereas the other factor had the opposite haemolytic pattern. The cytotoxicity of each factor was neutralized by the antiserum formed against the cytotoxin. A cytotoxic factor that exhibited haemolytic activity for rabbit erythrocytes, and that was neutralized by the cytotoxin antiserum, was identified in burn wound extracts of mice infected with Staph. aureus. On the basis of molecular weight and isoelectric focusing data, we conclude that the large molecular weight cytotoxin was composed of an aggregation of alpha-haemolysin and another presently unidentified toxic molecule, possibly delta-toxin. Alpha-haemolysin appears to be produced in vivo during experimental staphylococcal burn wound infection. 相似文献
38.
Brendan M McGuire Herbert L Bonkovsky Robert L Carithers Raymond T Chung Leonard I Goldstein John R Lake Anna S Lok Carol J Potter Elizabeth Rand Michael D Voigt Pamela R Davis Joseph R Bloomer 《Liver transplantation》2005,11(12):1590-1596
In erythropoietic protoporphyria (EPP), there is excessive production of protoporphyrin, primarily in the bone marrow, resulting in increased biliary excretion of this heme precursor. Some patients will develop progressive liver disease that may ultimately require liver transplantation. However, excessive production of protoporphyrin by the bone marrow continues after transplantation, which may cause recurrent disease in the allograft. This study was performed to define post-transplant survival, the risk of recurrent disease, and specific management issues in patients transplanted for EPP liver disease. The patients studied consisted of twelve males and eight females, with an average age of 31 (range, 13-56) years at the time of transplantation. The estimated maximum MELD score prior to transplant was 21 (range, 15-29). Unique complications in the perioperative period were light induced tissue damage in four patients and neuropathy in six, requiring prolonged mechanical ventilation in four. Patient and graft survival rates were 85% at 1 year, 69% at 5 years, and 47% at 10 years. Recurrent EPP liver disease occurred in 11 of 17 patients (65%) who survived more than 2 months. Three patients were retransplanted at 1.8, 12.6, and 14.5 years after the initial transplant for recurrent EPP liver disease. In conclusion, the 5-year patient survival rate in patients transplanted for EPP liver disease is good, but the recurrence of EPP liver disease appears to diminish long term graft and patient survival. 相似文献
39.
Pamela Husmann Christoph Bourauel Michael Wessinger Andreas J?ger 《Journal of orofacial orthopedics》2002,22(5):199-211
Background: The vast range of orthodontic wires made of different alloys makes it increasingly difficult for orthodontists to judge them. Coated orthodontic wires form a group of innovative guiding archwires. Material and Methods: In the present in vitro study the frictional behavior of eight coated wires of different dimensions was investigated in archwire-guided canine retraction in the upper jaw. For this purpose five superelastic nickel titanium alloy wires (Titanol/reg; Low Force River Finish Gold and Gold 2: Forestadent®, Pforzheim Germany; Titanol® Superelastic tooth Sentalloy Ionguard: GAC, Central Islip, NY, USA; NITI Imagination: GAC, Central Islip, NY, USA), two #-titanium wires (TMA® Low Friction Ionguard: Ormco, Glendora, CA, USA; TMA® Low Friction Ionguard Purple: Ormco, Glendora, CA, USA) and one steel wire (Stainless steel Imagination: GAC, Central Islip, NY, USA) were selected. The coatings were made of Teflon® or polyethylene, and by ion implantation. Three uncoated archwires (Rematitan® Lite Dimple; Dentaurum, Pforzheim, German; Titanol® Low Force River Finish: Forestadent®, Pforzheim, Germany; BioForce Sentalloy: GAC, Central Islip, NY, USA) were used for comparison purposes. The force losses due to friction were measured using the Orthodontic Measurement and Simulation System (OMSS). Results: The results indicated that all coatings can reduce frictional losses compared with an uncoated reference wire by the same manufacturer. Measured frictional losses ranged from 48.3-6.1% with the Teflon® coatings reducing the frictional losses to less than 10% in some cases. Conclusion: An unequivocal correlation between the surface roughness and frictional forces of the wires could not be verified by scanning electron microscopy. Zusammenfassung Hintergrund: Die Vielzahl an orthodontischen Drähten aus diversen Legierungen macht es die Kieferorthopäden immer schwerer, sie zu beurteilen. Eine Gruppe von neu angebotenen Führungsbögen stellen die beschichteten orthodontischen Drähte dar. Material und Methode: In der vorliegenden In-vitro-Studie wurde das Reibungsverhalten von acht beschichteten Drähten unterschiedlicher Dimension bei den bogengeführten Eckzahnretraktion im Oberkiefer untersucht. Neben fünf Nickel-Titan-Drähten (Titanol® Low Force River Finish Gold und Gold 2: Fa. Forestadent®; Titanol® Superelastic zahnfarben: Fa. Forestadent®; BioForce Sentalloy Ionguard: Fa. GAC; NiTi Imagination: Fa. GAC) wurden zwei #-Titan- (TMA Low Friction Iongard: Fa. Ormco; TMA Low Friction Ionguard Purple: Fa. Ormco) und ein Stahldraht (Stainless Steel Imagination: Fa. GAC) ausgewählt. Die Beschichtungen bestanden aus Teflon®, Polyethylen oder Ionenimplantation. Als Referenz wurden drei unbeschichtete Drähte (Rematitan® Lite Dimple: Fa. Dentaurum; Titanol® Low Force River Finish: Fa. Forestadent®; BioForce Sentalloy: Fa. GAC) in die Untersuchung einbezogen. Die Reibungsverluste wurden mit dem Orthodontischen Mess- und Simulations-System (OMSS) bestimmt. Ergebnisse: Die Ergebnisse zeigten, dass alle Beschichtungen, verglichen mit einem unbeschichteten Referenzdraht desselben Herstellers, eine Reduktion der Reibungsverluste bewirken. Die gemessenen Reibungsverluste lagen zwischen 48,3% und 6,1%, wobei bei Teflon®-Beschichtungen der Reibungsverlust zum Teil auf unter 10% sank. Schlussfolgerung: Ein eindeutiger Zusammenhang zwischen der Oberflächenrauheit und den Friktionswerten der Drähte konnte anhand von rasterelektronenmikroskopischen Aufnahmen nicht bestätigt werden. 相似文献
40.
Wilson's disease in children: 37-year experience and revised King's score for liver transplantation.
Anil Dhawan Rachel M Taylor Paul Cheeseman Pamela De Silva Leah Katsiyiannakis Giorgina Mieli-Vergani 《Liver transplantation》2005,11(4):441-448
Wilson's disease (WD) is a rare liver-based disorder of copper metabolism. Prognostic criteria described by our group in 1986 to predict death without transplantation have not been universally validated. The clinical features of 88 children were reviewed, retrospectively in 74 and prospectively in 14. Data from the retrospectively recruited patients that died or survived on long-term chelation were used to evaluate the validity of our old scoring system and to devise a new prognostic index, then assessed in the 14 prospectively recruited patients. Using the old scoring system, 5 children scoring > or = 7, the cutoff value for death without transplantation, survived, whereas 4 scoring < or = 7 died (sensitivity 87% and specificity 90%). A new index based on serum bilirubin, international normalized ratio, aspartate aminotransferase (AST), and white cell count (WCC) at presentation identified a cutoff score of 11 for death and proved to be 93% sensitive and 98% specific, with a positive predictive value of 88%. When the new index was evaluated prospectively in 14 patients, it predicted the need for transplantation in only the 4 who required it, although 1 child with a score of 11 survived on medical treatment. In conclusion, the new Wilson Index is more sensitive and specific in predicting mortality without transplantation than the old scoring system, but needs to be validated in a larger number of patients. 相似文献