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71.
Ultrastructural analysis of murine megakaryocyte maturation in vitro: comparison of big-cell and heterogeneous megakaryocyte colonies 总被引:1,自引:0,他引:1
Two morphologically distinct types of murine megakaryocyte (MK) colonies are present after three to seven days in soft agar culture: (a) "big-cell" colonies composed of ten to 30 large, mature-appearing megakaryocytes and (b) "heterogeneous" colonies consisting of approximately 100 or more cells at various stages of differentiation. Cytochemical and immunocytochemical techniques were used to study MK maturation in colonies as well as normal mouse bone marrow. Acetylcholinesterase (AChE), a specific marker for murine platelets and MK, was found in the perinuclear cisterna, endoplasmic reticulum, and occasionally, Golgi cisternae of MK in three-day big-cell colonies and immature bone marrow MK. MK in seven-day big-cell colonies and mature bone marrow MK showed additional reaction sites in the demarcation membrane system and occasional granules. In seven-day heterogeneous colonies, small cells resembled immature bone marrow MK with respect to AChE localization, whereas large cells corresponded to mature bone marrow MK. With immunogold procedures at the ultrastructural level, polyclonal antibodies against human platelet membrane glycoprotein IIIa and antimouse platelet antiserum labeled bone marrow MK and all MK from colonies grown in soft agar cultures for three to seven days. Granulocytes and macrophages in both bone marrow and soft agar cultures were negative for AChE and these immunocytochemical markers. These data indicate that the pattern of expression of AChE during maturation of MK is similar in vivo and in vitro and demonstrate, when using this marker at the fine-structural level, that a greater range of MK maturational stages is present in heterogeneous colonies than is observed in MK in big-cell colonies. Furthermore, we have confirmed that small cells in heterogeneous colonies are MK and that these colonies are composed solely of MK and their precursors. 相似文献
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73.
Human herpesvirus 6: infection and disease following autologous and allogeneic bone marrow transplantation 总被引:3,自引:0,他引:3
Kadakia MP; Rybka WB; Stewart JA; Patton JL; Stamey FR; Elsawy M; Pellett PE; Armstrong JA 《Blood》1996,87(12):5341-5354
Human herpesvirus 6 activity (HHV-6) was studied in 15 allogeneic and 11 autologous marrow transplantation patients. After transplantation, HHV-6 was isolated from the peripheral blood mononuclear cells of 12 of 26 patients (6 allogeneic and 6 autologous). All isolates were variant B. Eleven of 26 and 12 of 19 patients showed salivary shedding of HHV-6 DNA before and after transplantation, respectively. The antibody titer increased in 7 of 26 patients. Thus, 23 of 26 patients showed evidence of active HHV-6 infection either by virus isolation, salivary shedding, or increases in antibody titers. The fraction of saliva specimens positive in 19 patients was negatively associated with their antibody titers (P= .005). The proportion of cultures positive increased after transplantation (P = .007). Sinusitis was associated with HHV-6 isolation in autologous recipients (P= .002). In allogeneic patients, active human cytomegalovirus infection was associated with HHV-6 isolation (P = .04). No association was observed between HHV-6 infection and GVHD, pneumonia, delay in engraftment, or marrow suppression. Of the 120 clinical events analyzed in 26 patients, HHV-6 was defined as a probable cause of 16 events in 9 patients based on the propinquity of HHV-6 activity and the clinical event plus the absence of other identified causes of the event. 相似文献
74.
Human granulocytes generated in continuous bone marrow culture are physiologically normal 总被引:1,自引:0,他引:1
A long-term bone marrow culture system has been derived for maintenance and proliferation of human hemopoietic stem cells and granulocytes in vitro for up to 20 wk. The granulocytes generated in these cultures at 8 wk were comparable to fresh human peripheral blood granulocytes in physiologic properties, including phagocytosis, degranulation, respiratory burst, and bacterial killing: individual granulocytes generated up to 20 wk in several cultures demonstrated normal superoxide-generating capacity by NBT dye reduction slide test. Thus, human granulocytes generated in continuous marrow culture retain many biologic functions associated with bacterocidal capacity in vivo and indicate that this system should be of value in studies of disorders of granulocyte differentiation. 相似文献
75.
Illness Perceptions Explain the Variance in Functional Disability,but Not Habitual Physical Activity,in Patients With Chronic Low Back Pain: A Cross‐Sectional Study
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76.
Oral Diseases (2010) 16 , 729–739 The colonization of oral surfaces by micro‐organisms occurs in a characteristic sequence of stages, each of which is potentially amenable to external intervention. The process begins with the adhesion of bacteria to host receptors on epithelial cells or in the salivary pellicle covering tooth surfaces. Interbacterial cell–cell binding interactions facilitate the attachment of new species and increase the diversity of the adherent microbial population. Microbial growth in oral biofilms is influenced by the exchange of chemical signals, metabolites and toxic products between neighbouring cells. Bacterial cells on tooth surfaces (dental plaque) produce extracellular polymers such as complex carbohydrates and nucleic acids. These large molecules form a protective matrix that contributes to the development of dental caries and, possibly, to periodontitis. The identification of key microbial factors underlying each step in the formation of oral biofilms will provide new opportunities for preventative or therapeutic measures aimed at controlling oral infectious diseases. 相似文献
77.
78.
BM Dent A Al Samaraee PE Coyne C Nice M Katory 《Annals of the Royal College of Surgeons of England》2010,92(7):e10-e11
Pregnancy is a recognised risk factor for the development of inguinal hernias due to an increase in intra-abdominal pressure. Whilst often managed conservatively until after the pregnancy, if the hernia presents acutely as a painful or tender groin lump, urgent or emergency repair may be required. Many clinicians rely heavily on clinical examination alone in order to diagnose the presence of such a hernia. In pregnancy, however, in order to prevent unnecessary surgery, the use of ultrasound has a more important role to play in reaching this diagnosis. We report a cautionary case that highlights the need for ultrasound evaluation of all painful groin lumps in pregnant women prior to considering surgery. 相似文献
79.
80.
Berna DL Broekhuizen Alfred PE Sachs Arno W Hoes Karel GM Moons Jan WK van den Berg Willem H Dalinghaus Ernst Lammers Theo JM Verheij 《The British journal of general practice》2010,60(576):489-494