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971.
JR Gomez MJ Garcia J Serrano J Sanchez M Falcon JA Castillejo JA Navarro C Martin A Torres 《Canadian Metallurgical Quarterly》1997,82(5):588-591
BACKGROUND AND OBJECTIVE: Allogeneic bone marrow transplantation (BMT) is the most common treatment for young patients with severe aplastic anemia (SAA). Late graft failure represents one of the possible unfavorable outcomes in this setting. Mixed chimerism might represent a risk factor for late graft failure. We examined this relationship by studying chimerism in long-term survivor SAA patients after allogeneic BMT. METHODS: We analyzed long-term hematopoietic chimerism in 15 patients who received BMTs for SAA: 9 with an irradiation-based conditioning regimen and 6 with ATG. We used a PCR method targeting VNTR loci. Sensitivity of the technique ranged between 0.5 and 1.5%. RESULTS: All patients conditioned with radiation-based schemes showed complete donor chimerism. Conversely, out of six patients who received cyclophosphamide and ATG as a conditioning regimen, only one of them had late graft failure (day +168). In this patient, durable mixed chimera status was first detected two months after BMT. INTERPRETATION AND CONCLUSIONS: Our results suggest that in long-term survivors of SAA after BMT there is almost always complete donor chimerism in both irradiated and ATG-conditioned recipients. Mixed chimerism might predict graft failure in these patients. 相似文献
972.
973.
We have previously described a delta-opioid receptor-expressing cultured cell line that proliferates in a defined medium and responds to chronic morphine treatment with an inhibition of its rate of proliferation. To help provide an explanation for this behavior, we have used computer simulation of cell cycle kinetics to analyze the observed rates of proliferation of these cells in the presence and absence of morphine, and after withdrawal of morphine treatment. We questioned whether the difference in cell kinetics observed for the cell populations under the different treatments could be due to changes in the length of the cell cycle, withdrawal of cells from the cycle into a quiescent state, or differences in cell renewal. This was investigated by comparing observed cell numbers as a function of time with the results of different computer simulations using different values for these parameters. We found that we can provide a satisfactory explanation of the experimental observations on the basis of changes in a small set of parameters: Untreated cells experience a slowdown of cell proliferation at about the culture density where multiple cell-cell contacts are made and, beginning then, a large fraction are shunted from G1 into a quiescent state. Chronic morphine treatment inhibits proliferation by slowing passage through G1, but the cells remain as sensitive to cell-cell contacts as the untreated cells. After drug withdrawal following a 6 day treatment with morphine, the cells exhibit a large temporary increase in their rate of proliferation compared with control or chronically treated cells but about 48 hours after withdrawal, when cell-cell contacts just begin to be made, the cells return to almost their pre-treatment total cell cycle time and, as before, a large fraction are shunted into a quiescent state. Taken in conjunction with previously published results, the present ones indicate a possible interaction between morphine-induced and insulin-induced nuclear signaling pathways to the nucleus. 相似文献
974.
B Donahue CB Scott JS Nelson M Rotman KJ Murray DF Nelson FL Banker JD Earle JA Fischbach SO Asbell LE Gaspar AM Markoe W Curran 《Canadian Metallurgical Quarterly》1997,38(5):911-914
PURPOSE: Seven percent of patients with high grade gliomas enrolled in RTOG 83-02 had mixed astrocytoma/oligodenroglial elements on central pathology review. It has often been assumed that the most aggressive histologic component of a tumor determines biologic behavior; however in this trial, the survival of patients who had mixed glioblastomas/oligodenrogliomas was significantly longer than that of patients with pure glioblastomas (GBM). We therefore evaluated the effect of an oligodendroglial component on the survival of patients who had anaplastic astrocytomas (AAF) treated in the same trial. METHODS AND MATERIALS: One hundred nine patients who had AAF and 24 patients with mixed AAF/oligodendrogliomas (AAF/OL) were enrolled in a Phase I/II trial of randomized dose-escalation hyperfractioned radiotherapy plus BCNU. AAF/OL patients were older and more likely to have had more aggressive surgery than AAF patients. Other pretreatment characteristics were balanced between groups, as was assigned treatment. RESULTS: The median survival time for AAF was 3.0 years versus 7.3 years for AAF/OL (p = 0.019). In a multivariate analysis, adjusting for extent of surgical resection and age, an oligodendroglial component was an independent prognostic factor for survival. CONCLUSION: The results support the concept that AAFs with an oligodendroglial component have a better prognosis than pure AAF tumors, similar to the effect seen among patients with glioblastoma multiforme tumors. This better survival outcome should be taken into consideration in the design and stratification of future trials. Additionally, in contrast to patients with GBMs, patients who have AAF/OL have the potential for prolonged survival; therefore, late sequelae of treatment (both radiation and chemotherapy) must be weighed more heavily in the benefits to risks analysis. 相似文献
975.
JA Garrity 《Canadian Metallurgical Quarterly》1997,104(6):903-904
Chronic pancreas transplant rejection with enteric exocrine drainage can lead to significant long-term complications. We report a case of a 47-year-old male insulin-dependent diabetic who survived the complications of peripancreatic abscess, enterocutaneous fistula, and arterioenteric fistula related to pancreas transplantation. To avoid these long-term complications, we now recommend elective removal of nonfunctioning, enterically drained pancreas allografts. 相似文献
976.
JA Molina F de Bustos FJ Jiménez-Jiménez J Benito-León M Ortí-Pareja T Gasalla A Tallón-Barranco JA Navarro J Arenas R Enríquez-de-Salamanca 《Canadian Metallurgical Quarterly》1997,104(11-12):1287-1293
We compared CSF and serum levels, and the CSF/serum ratio of alpha-tocopherol (vitamin E), measured by HPLC, in 34 patients with Parkinson's disease (PD) and 47 controls. CSF and serum vitamin E levels were correlate. The mean CSF and serum vitamin E levels, and the CSF/serum ratio of PD patients did not differ significantly between the groups. There was no influence of antiparkinsonian therapy on CSF vitamin E levels. CSF vitamin E levels did not correlate with age, age at onset, duration of the disease, scores of the Unified Parkinson Disease Rating Scale of the Hoehn and Yahr staging in the PD group. These results suggest that CSF vitamin E concentrations are unrelated with the risk for PD. 相似文献
977.
Endocytosis and recycling of G protein-coupled receptors 总被引:1,自引:0,他引:1
Agonist stimulation of G protein-coupled receptors causes a dramatic reorganization of their intracellular distribution. Activation of receptors triggers receptor endocytosis and, since receptors recycle back to the surface continuously, a new steady state is reached where a significant proportion of receptors is located internally. Although this movement of receptors is remarkable, its role has been enigmatic. Recent developments have provided insight into the compartments through which the receptors move, the nature of the signals that trigger receptor translocation, and the significance of receptor cycling for cell function. In this article, Jennifer Koenig and Michael Edwardson review recent progress in this field and place receptor cycling into a mathematical framework that reveals the extent and rate of intracellular receptor movement. 相似文献
978.
JA Knight 《Canadian Metallurgical Quarterly》1997,27(1):11-25
Starting at infancy and continuing throughout adult life, huddling is a major component of the behavioral repertoire of Norway rats (Rattus norvegicus). Huddling behavior maintains the cohesion of litters throughout early life, and in adulthood, it remains a consistent feature of social behavior of R. norvegicus. During infancy, rats have severely limited sensorimotor capabilities, and yet they are capable of aggregating and display a form of group regulatory behavior that conserves metabolic effort and augments body temperature regulation. The functions of huddling are generally understood as group adaptations, which are beyond the capabilities of the individual infant rat. We show, however, that huddling as aggregative or cohesive behavior can emerge as a self-organizing process from autonomous individuals following simple sensorimotor rules. In our model, two sets of sensorimotor parameters characterize the topotaxic responses and the dynamics of contact in 7-day-old rats. The first set of parameters are conditional probabilities of activity and inactivity given prior activity or inactivity and the second set are preferences for objects in the infant rat's environment. We found that the behavior of the model and of actual rat pups compare very favorably, demonstrating that the aggregative feature of huddling can emerge from the local sensorimotor interactions of individuals, and that complex group regulatory behaviors in infant rats may also emerge from self-organizing processes. We discuss the model and the underlying approach as a paradigm for investigating the dynamics of social interactions, group behavior, and developmental change. 相似文献
979.
The implantable cardioverter-defibrillator (ICD) is an implantable electronic device that has been proven to be safe and effective in treating various malignant tachyarrhythmias in susceptible individuals. As the use of ICDs becomes more widespread, more individuals with the implanted devices will be encountered at autopsy. Manipulation of an activated ICD can result in electrical shock. To avoid injury, pathologists must be properly prepared to deal with bodies containing activated ICDs. These devices can also provide valuable information that may be helpful in determining the cause and mechanism of death. Herein, we present information regarding the appropriate guidelines and safeguards for pathologists confronted with an activated ICD. 相似文献
980.
We describe a case of an abdominal pregnancy which presented in the first trimester with rapid accumulation of blood stained ascites. The ascites resolved completely following surgical removal of a gestational sac from the peritoneal cavity. The pathophysiology of ascites in this case may be similar to that in cases of ascites in other non-malignant gynaecological conditions. 相似文献