Malignant thymomas are among the least common mediastinal tumors in the pediatric age group. Thymomas are considered malignant on the basis of macroscopic and microscopic invasiveness. As only 20 well-documented cases involving children have been reported in the literature, the pattern of responsiveness to therapy and the value of prognostic signs is obscure. Two cases of malignant pediatric thymomas are reported with pathognomonic histoimmunological features of aggressive thymoma. One was cured, with a follow-up of 70 months, and one died while on therapy. Analysis of the histological features and the immunoperoxidase staining displays the complexity of pediatric thymomas and the inability to prognosticate the outcome, respectively. 相似文献
Microvascular complications, including retinopathy and nephropathy are seen with type 1 diabetes. It is unknown whether functional
changes in aqueous humor flow or intraocular pressure (IOP) develop in parallel with these complications. This study was designed
to test the hypothesis that clinical markers of microvascular complications coexist with the alteration in aqueous humor flow
and IOP. 相似文献
CD14, a lipopolysaccharide (LPS) receptor, is present on the surface membrane of phagocytic leukocytes; it is also present in a soluble form in serum. Recently published results confer to this molecule novel functions that are linked to T-cell activation and to apoptosis. We report here that we have defined and characterized a novel lymphocyte population in human peripheral blood, a population that expresses an intracellular antigen detectable with MO2, a monoclonal antibody directed against the human CD14 molecule. This population is composed primarily of CD8-positive T-cells. We found surprisingly that this novel MO2-positive population of lymphocytes was greatly enhanced in asymptomatic, untreated HIV-positive individuals. 相似文献
Serum from young normal BALB/c mice was found to contain IgM antibodies able tomediate complement-dependent lysis of certain syngeneic or allogeneic tumor target cells. The titer of such naturally occurring antitumor antibodies (NATA) was found to increase with aging.A longitudinal serological study comparing the cytotoxicity potential of NATA fromnormal and from urethan-treated BALB/c mice was performed. It was found that urethan-treated mice that did not develop primary lung-adenomas within the duration of the experi-ment had significantly lower NATA titers, against one out of 4 target cells assayed, than urethan-treated animals that developed lung adenomas. This difference was evident in two independent experiments. The results suggested that the lower NATA activity of the urethan-treated mice that did not develop tumors existed even before exposure to the carcinogenic insult. This raises the possibility that certain populations could be segregated according to their natural antibody profile into those individuals which will develop primary tumors within a certain period if exposed to a subthreshold amount of carcinogen, and those which will not. 相似文献
The parameters that characterize the intricate water diffusion in tumors may serve to reveal their distinct pathology. Specifically, the application of diffusion magnetic resonance imaging (MRI) can aid in characterizing breast cancer, as well as monitoring response to therapy. We present here a non-invasive, quantitative MRI investigation, at high spatial resolution, of water diffusion in hormonal dependent MCF7 breast tumors implanted orthotopically in immunodeficient mice. Distinctive MRI protocols were designed in this study, utilizing a broad range of diffusion times and diffusion gradient strengths. Application of these protocols allowed water diffusion in the tissue extracellular and intracellular compartments to be distinguished, and the effect of restricted diffusion and water exchange on the water diffusion in these compartments to be evaluated. Pixel-by-pixel analysis yielded parametric maps of the estimated volume fraction and apparent diffusion coefficient of each compartment. The diffusion of the water in the extracellular microenvironment was approximately two fold slower than that of free water, and in the intracellular compartment was about one order of magnitude slower than that of free water and demonstrated restriction of water diffusion at long diffusion times. Mapping of the water fraction in each compartment was further employed to monitor changes during tumor progression and to assess tumor response to hormonal manipulation with a new antiestrogenic drug, tamoxifen methiodide (TMI). It was found that, in parallel to the growth arrest by this drug, the volume fraction of the slowly diffusing water increased, suggesting a TMI-induced cell swelling. This study can serve as a basis for extending diffusion breast MRI in the clinical setting. 相似文献
This qualitative study is intended to elucidate Lakota elders’ views on traditional tobacco and commercial/addictive tobacco use, capturing the oral history that depict the cultural protocol regarding traditional tobacco, called Cansasa. Commercial tobacco use has significantly impacted the Northern Plains Indians. National surveillance systems report that tobacco use is more prevalent among American Indian/Alaska Natives than any other population, and is notably higher than the national average. Lung cancer among Native Americans is highest in the Northern Plains and Alaska, where smoking prevalence is also the highest, and smoking is responsible for nearly 90 % of all lung cancer cases. Yet, the use of traditional tobacco is largely ignored by surveillance and seems to have a distinct, positive role. Using a community-based participatory research approach, semi-structured interviews, and qualitative analysis tools, the research team, including 2 Lakota tribe elders, Lakota speaking tribal college students, and university faculty, sought to discern tribal elders’ distinctions between traditional and the addictive commercial tobacco. The team interviewed thirty Lakota elders, transcribed the interviews and field notes, and analyzed them using immersion/crystallization organizing framework. The research design engaged the Lakota tribal community in all stages, from planning to publication. Analysis revealed a clear distinction between traditional and commercial tobacco: tribal elders conveyed strong positive messages connected to traditional tobacco use (i.e., spirituality, respect, health and wellness, humility, and thoughtfulness) versus strong negative messages linked to addictive tobacco (i.e., crime, loss of control and self-esteem, lack of respect to self and others, sickness and death). These messages, along with stories in the Lakota language that were told and recorded during the interviews, can guide new ways to address addictive tobacco prevention in this community, to enhance cultural pride, and to serve as a cross-generation bridge regarding tobacco use. 相似文献
Purpose: Problem-based learning (PBL) is an educational method that fosters self-directed study in small groups. The purpose of this study was to describe the Tel Aviv University’s occupational therapy (OT) program and the challenges implementing such program. In addition, the study compared the PBL grades obtained by students who are native Hebrew speakers with those students who are native Arabic speakers; and, assessed the correlation between the grades in the PBL course and the grades in the clinical fieldwork studies.
Method: 166-second year OT undergraduate students participated. All completed three PBL courses and seven weeks of clinical fieldwork studies. Data collection included students’ grades in PBL course (based on PBL evaluation forms) and in clinical fieldwork studies (based on preceptor’s evaluation and a written assignment).
Results: Pearson correlations revealed significant correlations between PBL grades and clinical fieldwork studies grades. T-test analysis between students who are native Hebrew speakers and those who are native Arabic speakers revealed significant differences in PBL grades.
Conclusions: Findings imply partial congruence between students’ grades in the PBL course and their achievements in the fieldwork studies. Findings might suggest that adjustments should be made in order to assist students from minorities (challenged by language requirements) in gaining higher grades in the PBL program.
Implications for Rehabilitation
Problem-Based Learning (PBL) is an educational method, which fosters independent, self-directed study in small groups.
PBL studies have the potential to prepare students for their clinical experience during studies.
The PBL program should be adjusted for students from minorities (challenged by language requirements and different cultural backgrounds) in order to assist them in gaining more benefits from the program.