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103.
Maria A. Giovino Robert J. Hawley Matt W. Dickerson Roseann Glaser Deborah H. Meshulam Robert Ardtsini Margaret D. Rosa Rod L. Monroy 《Xenotransplantation》1997,4(2):112-119
Abstract: Establishment of mixed bone marrow chimerism in pig-to-primate transplantation, as a means of inducing specific immune tolerance, will require that both immune and nonimmune barriers be overcome. As a preliminary step in evaluating nonimmune barriers in this system, we have developed an in vitro model of engraftment in which long-term culture of porcine bone marrow-derived hematopoietic cells is supported on preformed primate bone marrow stromal layers. In the absence of cytokine supplementation, primate stromal cells were unable to support long-term porcine hematopoiesis in these cultures. Supplementation with porcine Steel Factor was required for long-term maintenance of hematopoietic progenitor cell content and total hematopoietic activity. Addition of porcine IL-3, in combination with porcine Steel Factor, increased long-term progenitor cell content and hematopoietic activity on primate stroma to levels comparable to that obtained in cultures on porcine stroma. The combination of porcine GM-CSF and Steel Factor increased progenitor cell content and hematopoietic activity early in the cultures, but had little effect in long-term cultures. The Steel Factor and IL-3 combination was species-specific in its action in these cultures, as the corresponding human cytokines were unable to effectively support long-term porcine hematopoiesis. Likewise, the combination of porcine cytokines had only minimal effects on long-term bone marrow culture of primate CD34+ cells I on primate stroma. 相似文献
104.
Koichi Masuda Robert L Sah Michael J Hejna Eugene J-M A Thonar 《Journal of orthopaedic research》2003,21(1):139-148
Most attempts to tissue-engineer cartilage have involved seeding of cultured cells into a biological or synthetic scaffold. We have developed a novel two-step culture approach that makes possible the in vitro formation of cartilaginous-like tissue by mature adult bovine chondrocytes without the aid of a synthetic matrix. The first step consists of culturing chondrocytes under conditions that maintain their rounded shape and their molecular phenotype as assessed by type II collagen and aggrecan production. This step was accomplished by culturing the isolated chondrocytes in alginate beads until the cells have reestablished a proteoglycan-rich cell-associated matrix (CM). The second step consists of culturing the cells with their CM, after recovery from the beads, on a tissue culture insert with a porous membrane. In this study, young adult bovine articular chondrocytes were cultured in alginate beads in the presence of 10% or 20% fetal bovine serum (FBS). After 7 days of culture, the alginate beads were dissolved by incubating the beads for 20 min in sodium citrate buffer, a calcium chelator. Following a brief centrifugation, the cells with their CM were recovered, resuspended in medium containing 10% or 20% FBS and seeded onto a tissue culture insert. After 1 week of culture on the insert, the individual cells with their CM progressively became incorporated into a mass of cartilaginous tissue. Culture with 20% FBS resulted in the best formation of tissues. These tissues, easily recovered from the insert, were then subjected to biochemical and histological analyses. The biochemical results showed that the chondrocytes remain phenotypically stable in the tissues. The de novo tissue has a relatively high ratio of PG/collagen. Histological examination of the tissue revealed it contained a cartilage-like matrix strongly stained with toluidine blue. This scaffold-free system appears ideal to study, in vitro, the development of transplantable cartilaginous tissue. 相似文献
105.
B. A. Johnson Donald R. Jasinski Gantt P. Galloway Henry Kranzler Robert Weinreib Raymond F. Anton Barbara J. Mason Michael J. Bohn Helen M. Pettinati Richard Rawson Christopher Clyde 《Psychopharmacology》1996,128(2):206-215
Four hundred and twenty-three alcohol dependent subjects were enrolled into a 12-week randomized, double-blind, placebo-controlled
study to determine the safety and efficacy of the 5-HT2 receptor antagonist, ritanserin (2.5 mg/day or 5 mg/day), in reducing alcohol intake and craving. All subjects received 1
week of single-blind placebo prior to randomization into the 11-week double-blind phase. Additionally, all subjects received
weekly individual sessions of manual-guided cognitive-behavioral therapy. Comparing the single-blind period with endpoint,
there was approximately a 23% reduction in drinks/day; 34% fall in the total number of drinking days/week; 22% decrease in
drinks/drinking day; and a 37% diminution in alcohol craving for all treatment groups. All treatment groups experienced a
beneficial clinical outcome as assessed by the Clinical Global Impression Scale. There was, however, no significant difference
between treatment groups on any of these measures of alcohol drinking, craving, or clinical outcome. Subjects were of relatively
high social functioning at baseline, and this did not change significantly during treatment. Treatment groups did not differ
significantly on either medication compliance or reported adverse events. Ritanserin treatment was associated with a dose-related
prolongation of subjects’ QTc interval recording on the electrocardiogram. These results suggest that alcohol dependent subjects
can show marked clinical improvement within a structured alcohol treatment program. These findings do not support an important
role for ritanserin in the treatment of alcohol dependence.
Received: 30 April 1996/Final version: 3 July 1996 相似文献
106.
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108.
Herbert Radner Yosuf El-Shabrawi Robert H. Eibl Oliver Brüstle Lukas Kenner Paul Kleihues Otmar D. Wiestler 《Acta neuropathologica》1993,86(5):456-465
Introduction into fetal rat brain cells of a replication-defective retroviral vector harboring v-Ha-ras and v-gag-myc rapidly causes the induction of highly malignant undifferentiated neuroectodermal tumors following transplantation into the brains of syngeneic hosts [Wiestler, et al. (1992) Cancer Res. 52: 3760–3767]. In the present study, we have investigated the modulating effect of the developmental stage of neural target cells and of the dose of the retroviral vector used in the grafting experiments. Exposure of fetal cells from embryonic day (E)12 or E14 produced a 100% incidence of malignant neuroectodermal tumors which led to the death of recipient animals after a median latency period of 32 days. A 100-fold reduction of the virus dose from 2.062×106 to 2.062×104 focus-forming units/ml resulted in a lower tumor incidence of 25%. Of six neural grafts exposed to v-Ha-ras and v-myc at E16, only one showed evidence of tumorigenesis (low-grade astrocytoma and hemangioma). All other transplants were morphologically normal for observation periods of 26 weeks, indicating a marked loss of transforming activity of ras and myc in more advanced stages of brain development. In retrovirus-exposed donor cells which caused the development of neural tumors in recipient rats, malignant transformation was also evident during culture in vitro, usually after 9–12 days. Oncogene complementation was also studied in the newborn rat brain. After microinjection of the retroviral vector into the brain at postnatal day (P)0, P1 and P3, 5 out of 20 animals (25%) developed a total of seven brain tumors. Histopathologically, three of these neoplasms were malignant neuroectodermal tumors which, in contrast to those induced in fetal brain transplants showed evidence of focal glial and/or neuronal differentiation. In addition, we observed one oligodendroglioma, two hemangiomas and a malignant hemangioendothelioma. These data indicate that neural precursor cells and endothelia of the rat brain represent the major target cells for the complementary action of ras and myc and that the use of target cells from later developmental stages (E16 and postnatal) leads to the induction of both primitive and more differentiated neoplasms.These studies were supported by the Fonds zur Förderung der wissenschaftlichen Forschung in Österreich (Erwin Schrödinger fellowship, JO501-MED), by the Swiss National Science Foundation and by the Cancer League of the Kanton of Zürich 相似文献
109.
Venance Varille Jacques Paulus Dominique Robert 《Nutrition Clinique et Métabolisme》1998,12(4):289-295
Patients with neuromuscular diseases have protein malnutrition related to the muscle mass decrease. When associated with a decrease in food intake below requirements, patients become cachectic. Respiratory complications are then frequent and severe. In case of respiratory distress, the acute stress might aggravate the protein loss which will be particularly difficult to restore if the muscular activity is reduced. Although there are no curative therapies for neuromuscular diseases but all symptomatic treatments are useful in maintaining function and quality of life; therefore the prevention of malnutrition is essential. Nutritional care is difficult because of the lack of norms for body composition and protein and energy requirements. The nutritional support must take into account the swallowing difficulties, the digestive and polyvisceral involvement and the natural history of the disease. The nutritional support is usually enteral. Feeding through a gastrostomy tube, feasable at home, has improved the quality of life of the patient. Parenteral nutrition is prescribed for limited periods for surgery or acute respiratory failure. 相似文献
110.
Robert Hammaker Ed.D. 《Administration and policy in mental health》1996,23(3):261-269
Conclusions There is extensive evidence that perspectives on mental health consumer needs vary widely between consumers and other stakeholders-administrators, practitioners, and family members. Traditional methods of determining mental health consumer needs, based on professional input only, have inhibited program development. While progress has been achieved when shared goals have been identified, it has also been inhibited by a lack of known areas of consensus between stakeholder groups.Surveys provide a cost-effective step toward documenting shared views from stakeholders who have the greatest stake in influencing the size and direction of the mental health service system. Identifying shared views is necessary to coordinate stakeholder efforts. The most encouraging result of the surveys is that there are many areas of consensus and thus the potential exists for the stakeholders to coordinate their efforts toward shared goals to better meet important consumer needs by prioritizing services, improving practitioner training, and coordinating advocacy. 相似文献