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101.
Platelet adherence at high wall shear rates requires plasma von Willebrand factor (vWF). Clinically, the ristocetin cofactor (RCof) activity is the only widely available assay for vWF function. When purified vWF is treated with neuraminidase to yield asialo-vWF (AS- vWF), its RCof activity is increased by 20% to 40%. AS-vWF binds to normal human platelets independently of ristocetin and induces platelet aggregation in the presence of fibrinogen. To determine whether AS-vWF also shows an enhanced capacity to support platelet adherence to subendothelium, we used the Baumgartner technique. Intact vWF, AS-vWF, or AS-vWF treated with beta-galactosidase (asialo, agalacto-vWF; AS,AG- vWF) was added to normal citrated whole blood before perfusion over human umbilical artery segments (wall shear rate, 2,600 sec-1). Four micrograms per milliliter AS-vWF caused a 69% reduction in total platelet adherence compared with citrated whole blood (P less than .001), and 4 micrograms/mL AS,AG-vWF led to a 48% reduction (P less than .005). With 4 micrograms/mL intact vWF, the platelet adherence values were not significantly different from the controls. No significant differences in subendothelial platelet thrombi or postperfusion platelet counts were evident among any of the groups. In reconstituted afibrinogenemic perfusates, 4 micrograms/mL AS-vWF caused a 42% reduction in platelet adherence (P less than .05). Thus, AS-vWF is a potent inhibitor of platelet adherence, despite its enhanced RCof specific activity. Abnormalities in vWF carbohydrate may play a role in impaired primary hemostasis in some patients with von Willebrand's disease. 相似文献
102.
Nitric oxide (NO) is a paramagnetic gas that has been implicated in a wide range of biologic functions. The common pathway to evoke the functional response frequently involves the formation of an iron- nitrosyl complex in a target (heme) protein. In this study, we report on the interactions between NO and cobalt-containing vitamin B12 derivatives. Absorption spectroscopy showed that of the four Co(III) derivatives (cyanocobalamin [CN-Cbl], aquocobalamin [H2O-Cbl], adenosylcobalamin [Ado-Cbl], and methylcobalamin [MeCbl]), only the H2O- Cbl combined with NO. In addition, electron paramagnetic resonance spectroscopy of H2O-Cbl preparations showed the presence of a small amount of Cob-(II)alamin that was capable of combining with NO. The Co(III)-NO complex was very stable, but could transfer its NO moiety to hemoglobin (Hb). The transfer was accompanied by a reduction of the Co(III) to Co(II), indicating that NO+ (nitrosonium) was the leaving group. In accordance with this, the NO did not combine with the Hb Fe(II)-heme, but most likely with the Hb cysteine-thiolate. Similarly, the Co(III)-NO complex was capable of transferring its NO to glutathione. Ado-Cbl and Me-Cbl were susceptible to photolysis, but CN- Cbl and H2O-Cbl were not. The homolytic cleavage of the Co(III)-Ado or Co(III)-Me bond resulted in the reduction of the metal. When photolysis was performed in the presence of NO, formation of NO-Co(II) was observed. Co(II)-nitrosyl oxidized slowly to form Co(III)-nitrosyl. The capability of aquocobalamin to combine with NO had functional consequences. We found that nitrosylcobalamin had diminished ability to serve as a cofactor for the enzyme methionine synthase, and that aquocobalamin could quench NO-mediated inhibition of cell proliferation. Our in vitro studies therefore suggest that interactions between NO and cobalamins may have important consequences in vivo. 相似文献
103.
Lymphokine-induced phagocytosis in angiocentric immunoproliferative lesions (AIL) and malignant lymphoma arising in AIL 总被引:1,自引:1,他引:1
A factor that augmented the phagocytosis of IgG-coated ox red blood cells by the human monocyte/macrophage line U937 was identified in cell culture supernatants from two of two patients with angiocentric peripheral T cell lymphomas, three of three patients with angiocentric immunoproliferative lesions that were not frankly malignant, and one of two patients with T lymphoblastic malignancies. The factor was not present in supernatants derived from 14 nonangiocentric peripheral T cell lymphomas of other histologic types nor in ten cases of B cell lymphoma and two cases of Hodgkin's disease. A similar factor was present in the supernatants of concanavalin A (Con A)-stimulated normal peripheral blood mononuclear cells and in the supernatants of IL-2- dependent T cell lines derived from normal peripheral blood. The factor had an apparent mol wt of greater than 50,000 daltons, was heat labile (100 degrees C for two minutes), and stable at pH 2.0. Its stimulation of phagocytosis was independent of any increase in number of Fc receptors. Thus, this factor is probably not gamma-interferon. This factor may play a pathogenetic role in the hemophagocytic syndromes associated with certain T cell malignancies and immunodeficient states. 相似文献
104.
105.
U PODDAR Y CHAWLA RK DHIMAN K VAIPHEI RK VASISHTA JB DILAWARI 《Journal of gastroenterology and hepatology》1998,13(1):109-111
Ascites may be associated with fulminant hepatic failure (FHF), but spontaneous bacterial peritonitis (SBP) is an extremely rare complication. We report on two patients with FHF who developed SBP. One patient died and the other recovered. 相似文献
106.
107.
In vitro and in vivo selectin-blocking activities of sulfated lipids and sulfated sialyl compounds 总被引:2,自引:0,他引:2
Mulligan MS; Warner RL; Lowe JB; Smith PL; Suzuki Y; Miyasaka M; Yamaguchi S; Ohta Y; Tsukada Y; Kiso M; Hasegawa A; Ward PA 《International immunology》1998,10(5):569-575
There is accumulating evidence that sulfated lipids, sulfated
oligosaccharides and other sulfated compounds are reactive with selectins
in a manner that interferes with selectin interactions with their natural
ligands. In the report we describe the ability of sulfated lipids
(sulfatides and gangliosides) and multimeric forms of sulfated sialic acid
to block binding of P- and E-selectin-Ig to neutrophils. The in vivo
ability of these compounds to block lung injury in rats following i.v.
infusion of purified cobra venom factor (CVF), which induces injury that is
L- and P-selectin dependent, was also determined as well as effects on
recruitment of neutrophils, as measured by lung myeloperoxidase. There was
a significant correlation between the ability of sulfated lipids and sialyl
compounds to interfere in vitro with P-selectin-Ig binding to neutrophils
and to protect against P-selectin-dependent acute lung injury induced by
CVF. The biological effects of these sulfated compounds were also
associated with diminished accumulation of neutrophils. The protective
effects of these compounds may be linked to their ability to interfere with
P- selectin binding to counter-receptors on neutrophils.
相似文献
108.
Surgical division of craniopagi 总被引:7,自引:0,他引:7
The world's surgical experience on the division of craniopagi is reviewed, and a new case is reported. The problems, including ethical considerations, that must be addressed in selecting patients for operation and in preparing for the procedure are discussed in detail. Hemodynamic stability and the problem of intraoperative gravitational distortion of the brain are addressed. The importance of careful planning is stressed. Survival of the 31 craniopagi after operation is discussed in relation to types of junction. 相似文献
109.
Richard Lawrence Levy Gary F Rogers John B Mulliken Mark R Proctor Linda R Dagi 《Journal of AAPOS》2007,11(4):367-372
PURPOSE: Unilateral coronal synostosis alters orbital development and can be associated with strabismus, oblique muscle dysfunction, astigmatism, and amblyopia. While the ocular effects are most dramatic on the side of the fusion, the shape of the contralateral orbit is also abnormal and the effect of these changes on bilateral visual development has not been fully described. The purpose of this study was to analyze the incidence and laterality of astigmatism in children with unilateral coronal synostosis. METHODS: We retrospectively reviewed the charts of 39 consecutive patients with unilateral coronal synostosis. Recorded data included the following: patient demographics, visual acuity, cycloplegic refraction, ocular motility, procedures for craniofacial and strabismus correction, and presence and treatment of amblyopia at each visit. RESULTS: Twenty-one of 39 patients (54%) had 1.00 D or more astigmatism in at least one eye at their last recorded refraction. Sixteen of the 21 (76%) had aniso-astigmatism of 1.00 D or more. Of the 16, 14 (88%) had the greater degree of astigmatism in the contralateral eye. Fifteen of the 39 studied (38%) had amblyopia and, in 12 of these 15 patients (80%), the amblyopic eye was contralateral to the synostosis. Nineteen of 39 patients (49%) had greater ipsilateral fundus excyclotorsion, whereas only 1 of 39 (3%) had greater contralateral excyclotorsion. CONCLUSIONS: Patients with unilateral coronal synostosis are at risk for developing a greater degree of astigmatism in the eye contralateral to the synostosis. Ocular disturbances in the contralateral eye, especially anisometropic amblyopia, must be considered when treating patients with this type of craniosynostosis. 相似文献
110.
Correction of the bilateral cleft lip nasal deformity: evolution of a surgical concept. 总被引:1,自引:0,他引:1
J B Mulliken 《The Cleft palate-craniofacial journal》1992,29(6):540-545
The origin of the nasal deformity of a bilateral complete cleft lip is both primary (deformation/malformation) and secondary (postoperative distortion). This is an interim report of a personal evolution from staged correction of the bilateral cleft nasal deformity to synchronous repair of the nose and the lip and premaxillary-maxillary clefts. The anatomic concept is that, because of the malpositioned alar cartilages, the columella only appears to be short in an infant with bilateral cleft lip. The technical stratagems to model the nose are: (1) alignment of the premaxilla and (2) anatomic placement of the alar cartilages with sculpturing of the overlying soft tissue. 相似文献