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41.
M Centola K Lin C Sutton JR Berenson LA Kunkel L Rosen BH Hahn RR Robinson 《Canadian Metallurgical Quarterly》1996,20(5-6):465-469
We have assessed the specificity of antibodies from the leukemic B cells of five patients with both chronic lymphocytic leukemia and autoimmune hemolytic anemia (CLL-AHA). Leukemic cells from one patient displayed surface immunoglobulin with heavy and light chain isotypes identical to that of the patient's anti-red blood cell (RBC) antibodies, and the leukemic cells secreted antibodies in vitro with anti-RBC activity. However, in the remaining patients, the leukemic cells displayed surface immunoglobulin with light chain isotypes different from that of the patient's anti-RBC antibodies and secreted antibodies in vitro with no detectable anti-RBC activity. Thus, there are two distinct classes of CLL-AHA patients, differentiated by the presence or absence of an anti-RBC antibody-producing leukemic B cell clone. The apparent heterogeneity in the source of pathogenic anti-RBC antibodies may impact the treatment response of the two classes of CLL-AHA patients. 相似文献
42.
NM el-Sayed PJ Gomatos GR Rodier TF Wierzba A Darwish S Khashaba RR Arthur 《Canadian Metallurgical Quarterly》1996,55(2):179-184
Blood samples from 740 Egyptian Nationals working in the tourism industry at two sites in the South Sinai governorate were screened for markers of infection with hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and Treponema pallidum. Study subjects included 467 individuals from a rural seashore tourist village and 273 persons at two hotels in a well-established resort town. Subjects' ages ranged from 15 to 70 years; 99.3% were male. The prevalence of serologic markers for currently asymptomatic or past HBV infection alone was 20.7% (n = 153), of markers for past or chronic HCV infection alone was 7.4% (n = 55), and of markers for both HBV and HCV was 6.9% (n = 51). Of the 204 individuals positive for anti-HBV core antibody, 12 (5.9%) were also positive for hepatitis B surface antigen. Two individuals (0.3%) had a serologic market suggestive of an active syphilitic infection. No subject was found to be HIV-seropositive. History of prior injections and number of injections were associated with infection with HCV. Primary residence in the Nile delta and valley areas where schistosomiasis is highly endemic, was also a statistically significant risk factor for HCV, but not HBV infection. 相似文献
43.
RR Bosch AM Patel SE Van Emst-de Vries RL Smeets JJ De Pont PH Willems 《Canadian Metallurgical Quarterly》1998,346(2-3):345-351
We investigated the effects of nitric oxide (NO) donors, S-nitroso-N-acetylpenicillamine and sodium nitroprusside on basal and K+-evoked release of [3H]noradrenaline from superfused synaptosomes from the rat cerebral cortex. Both substances produced concentration-dependent increases in the release of the labeled transmitter under basal and depolarized conditions. The effects of the donors on basal release were Ca2+-independent but were not inhibited by the carrier-uptake blocker, desipramine; the effects were abolished by hemoglobin (an NO scavenger). Thirty-five minutes after stimulation with sodium nitroprusside, the synaptosomes were still responsive to KCl stimulation, indicating that the donor's effects were not caused by damage to the synaptosome membrane. The cGMP analogue, 8-bromo-cGMP, had no effect on basal release, and the enhanced release produced by sodium nitroprusside was not inhibited by the specific inhibitor of soluble guanylate cyclase, 1H-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one, indicating that NO's effects on basal release of the neurotransmitter are guanylate cyclase-independent. Both of the NO donors had more marked effects on release of [3H]noradrenaline during K+-stimulated depolarization. The NO-mediated increase in this case was partially antagonized by 10 microM LH-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one, and 8-Br-cGMP was also capable of producing concentration-dependent increases in the K+-stimulated release of the transmitter. These findings indicate that the effects of the NO donors on [3H]noradrenaline release during depolarization are partially mediated by the activation of guanylate cyclase. 相似文献
44.
The localization of cathepsin K protein in mouse osteoclasts was examined by immunolight and immunoelectron microscopy using the avidin-biotin-peroxidase complex method with anti-cathepsin K (mouse) antibody. With light microscopy, a strong immunoreaction for cathepsin K was found extracellularly along the bone and cartilage resorption lacunae and detected intracellularly in vesicles, granules, and vacuoles throughout the cytoplasm of multinuclear osteoclasts and chondroclasts attached to the surface of the bone or cartilage. Mononuclear cells, probably preosteoclasts, some distance from the bone also contained a few cathepsin K-positive vesicles and granules. Cathepsin K was sometimes found in the cisternal spaces of the rough endoplasmic reticulum and vesicles of the Golgi apparatus with electron microscopy of the basolateral region of the osteoclasts. Cathepsin K-positive vesicles and granules as lysosomal compartments were present in various stages of fusion with vacuoles as endosomal compartments that contained fragmented cathepsin K-negative fibril-like structures. Some of the vacuoles (endolysosomes), which seemed to be formed by this process of fusion, contained cathepsin K-positive vesicles and fibril-like structures that did not show the regular cross striation of type I collagen fibrils. In the apical region of the osteoclasts, cathepsin K-positive vesicles and pits had already fused with or were in the process of fusing with the ampullar extracellular spaces. There were large deposits of cathepsin K on fragmented fibril-like structures without regular cross striation in the extracellular spaces, as well as on and between the cytoplasmic processes of the ruffled border. There were also extensive deposits of cathepsin K on the type I collagen fibrils with cross striation in the bone resorption lacunae. Osteoblasts and osteocytes were negative for cathepsin K. In the immunocytochemical controls, no immunoreaction was found in the osteoclasts or preosteoclasts, or on the collagen fibrils in the resorption lacunae. The results indicate that cathepsin K is produced in mature osteoclasts attached to the bone and secreted into the bone resorption lacunae. The findings suggest that cathepsin K participates in the extracellular degradation of collagen fibrils in the resorption lacunae and in the subsequent degradation of the fragmented fibrils in the endolysosomes. It is also suggested that cathepsin K degrades the organic cartilage matrix. 相似文献
45.
AE Medvedev T Flo RR Ingalls DT Golenbock G Teti SN Vogel T Espevik 《Canadian Metallurgical Quarterly》1998,160(9):4535-4542
This study was undertaken to evaluate the role of CD14 and complement receptors type 3 (CR3) and 4 (CR4) in mediating TNF release and NF-kappaB activation induced by LPS and cell wall preparations from group B streptococci type III (GBS). LPS and GBS caused TNF secretion from human monocytes in a CD14-dependent manner, and soluble CD14, LPS binding protein, or their combination potentiated both LPS- and GBS-induced activities. Blocking of either CD14 or CD18, the common beta-subunit of CR3 and CR4, decreased GBS-induced TNF release, while LPS-mediated TNF production was inhibited by anti-CD14 mAb only. Chinese hamster ovary cell transfectants (CHO) that express human CD14 (CHO/CD14) responded to both LPS and GBS with NF-kappaB translocation, which was inhibited by anti-CD14 mAb and enhanced by LPS binding protein. While LPS showed fast kinetics of NF-kappaB activation in CHO/CD14 cells, a slower NF-kappaB response was induced by GBS. LPS also activated NF-kappaB in CHO cells transfected with either human CR3 or CR4 cDNA, although responses were delayed and weaker than those of CHO/CD14 cells. In contrast to LPS, GBS failed to induce NF-kappaB in CHO/CR3 or CHO/CR4 cells. Both C3H/OuJ (Lps[n]) and C3H/HeJ (Lps[d]) mouse peritoneal macrophages responded to GBS with TNF production and NF-kappaB translocation, whereas LPS was active only in C3H/OuJ macrophages. Thus, LPS and GBS differentially involve CD14 and CR3 or CR4 for signaling NF-kappaB activation in CHO cells and TNF release in human monocytes, and engage a different set of receptors and/or intracellular signaling pathways in mouse macrophages. 相似文献
46.
47.
E Sforza L Laks RR Grunstein J Krieger CE Sullivan 《Canadian Metallurgical Quarterly》1998,11(2):440-446
Recent results in animals have suggested that repetition of hypoxaemic stimuli may result in a progressive increase in pulmonary arterial pressure (Ppa). The purpose of the present study was to investigate the effects of recurrent obstructive apnoeas on Ppa. We have, therefore, examined the nocturnal trend of Ppa in seven obstructive sleep apnoea syndrome (OSAS) patients and in five snorers. Mean Ppa was measured before, at the start, at the end and after the selected apnoeas. The analysis was performed for each 1 h period for at least 7 h throughout the night on at least 10 randomly selected apnoeas per hour. In snorers, 100 randomly chosen values were measured during every hour of the night. In the morning after the nocturnal study, the Ppa responses to acute hypoxia and hypercapnia were measured. No Ppa changes throughout the 7 h were found during sleep in snorers [Ppa slope:-0.002+/-0.10 mmHg x h(-1)]. In OSAS patients a small but significant increase in Ppa throughout the night was noted, affecting the values before [Ppa slope: 0.7+/-0.16 mmHg x h(-1)], at the start of apnoea [Ppa slope: 0.530.1 mmHg x h(-1)] as well as at the end [Ppa slope: 0.44+/-0.08 mmHg x h(-1)] and in the postapnoeic period [Ppa slope: 0.55+/-0.1 mmHg x h(-1)]. When we limited the analysis to nonrapid eye movement (NREM) sleep, a trend in progressive Ppa was also present, irrespective of changes in apnoea duration and apnoea desaturation. The Ppa rise during the night was not affected by diurnal Ppa pulmonary vascular response to hypoxia and hypercapnia or indices of sleep apnoea severity. We conclude that in obstructive sleep apnoea, pulmonary artery pressure progressively increases during the night, reflecting the cumulative effects of apnoeas and nocturnal hypoxaemia. 相似文献
48.
PA White CI Brookes HB Ravn EE Stenb?g TD Christensen RR Chaturvedi K Sorensen VE Hjortdal AN Redington 《Canadian Metallurgical Quarterly》1998,38(3):668-675
OBJECTIVE: An important component of the ventricular volume measured using the conductance catheter technique is due to parallel conductance (Vc), which results from the extension of the electric field beyond the ventricular blood pool. Parallel conductance volume is normally estimated using the saline dilution method (Vc(saline dilution)), in which the conductivity of blood in the ventricle is transiently increased by injection of hypertonic saline. A simpler alternative has been reported by Gawne et al. [12]. Vc(dual frequency) is estimated from the difference in total conductance measured at two exciting frequencies and the method is based on the assumption that parallel conductance is mainly capacitive and hence is negligible at low frequency. The objective of this study was to determine whether the dual frequency technique could be used to substitute the saline dilution method to estimate Vc in different sized hearts. METHODS: The accuracy and linearity of a custom-built conductance catheter (CC) system was initially assessed in vitro. Subsequently, a CC and micromanometer were inserted into the left ventricle of seven 5 kg pigs (group 1) and six 50 kg pigs (group 2). Cardiac output was determined using thermodilution (group 1) and an ultrasonic flow probe (group 2) from which the slope coefficient (alpha) was determined. Steady state measurements and Vc estimated using saline dilution were performed at frequencies in the range of 5-40 kHz. All measurements were made at end-expiration. Finally, Vc was estimated from the change in end-systolic conductance between 5 kHz and 40 kHz using the dual frequency technique of Gawne et al. [12]. RESULTS: There was no change in measured volume of a simple insulated cylindrical model when the stimulating frequency was varied from 5-40 kHz. Vc(saline dilution) varied significantly with frequency in group 1 (8.63 +/- 2.74 ml at 5 kHz; 11.51 +/- 2.65 ml at 40 kHz) (p = 0.01). Similar results were obtained in group 2 (69.43 +/- 27.76 ml at 5 kHz; 101.24 +/- 15.21 ml at 40 kHz) (p < 0.001). However, the data indicate that the resistive component of the parallel conductance is substantial (Vc at 0 Hz estimated as 8.01 ml in group 1 and 62.3 ml in group 2). There was an increase in alpha with frequency in both groups but this did not reach significance. The correspondence between Vc(dual frequency) and Vc(saline dilution) methods was poor (group 1 R2 = 0.69; group 2 R2 = 0.22). CONCLUSION: At a lower excitation frequency of 5 kHz a smaller percentage of the electric current extends beyond the blood pool so parallel conductance is reduced. While parallel conductance is frequency dependent, it has a substantial resistive component. The dual frequency method is based on the assumption that parallel conductance is negligible at low frequencies and this is clearly not the case. The results of this study confirm that the dual frequency technique cannot be used to substitute the saline dilution technique. 相似文献
49.
Recurrent ventricular tachycardia and ventricular fibrillation were observed immediately after RF ablation of the AV junction in a 64-year-old man. This arrhythmia was preceded by ventricular bigeminy and a long-short sequence. It was not associated with prolongation of the QT interval compared to baseline, and recurred 3 months later despite ventricular pacing at 90 beats/min. This is the first reported case of sustained ventricular arrhythmia complicating RF AV junction ablation despite rapid ventricular pacing, and recurring 3 months after discharge. It may explain the rare cases of sudden death complicating this procedure. 相似文献
50.
TH Lee RR Stromberg JW Heitman L Sawyer CV Hanson MP Busch 《Canadian Metallurgical Quarterly》1998,38(6):580-588
BACKGROUND: Although inactivation of enveloped viruses transmitted by plasma derivatives has been successful, no methods for virus inactivation or removal have been established for platelet concentrates or red cell (RBC) components. Relatively little is known regarding the extent or significance of virus interactions with the cellular constituents in these components. STUDY DESIGN AND METHODS: Units of whole blood were collected from six HIV type 1 (HIV-1)-positive, asymptomatic individuals and separated into peripheral blood mononuclear cells (PBMNCs), cell-free plasma, white cell-reduced platelet concentrate, and white cell-reduced RBCs. DNA and RNA polymerase chain reaction and virus culture methods were used to study the compartmentalization of HIV-1 immediately after component preparation and after storage. RESULTS: As expected, HIV DNA and infectious virus were detected in fresh blood and in PBMNCs, and virion-associated RNA was detected in fresh plasma from all six donors. The levels of viral nucleic acids in these preparations remained relatively stable with 4 degrees C storage, whereas infectivity of PBMNCs was rapidly lost. Washed RBCs tested negative for HIV in all assays at all time points. Platelets retained high levels of HIV RNA (but not infectivity) after extensive washing, as well as after storage at 4 and 22 degrees C. High-level platelet-associated HIV-1 was also demonstrated in samples collected during early seroconversion. Periseroconversion and postseroconversion levels of platelet-associated HIV-1 correlated with the level of plasma viremia and with the rate of progression to AIDS. Cell-free virus from donor plasma and tissue culture fluid rapidly and firmly attached to platelets from noninfected donors. Infectivity of tissue culture virus bound to platelets was demonstrated in vitro. CONCLUSION: Significant levels of HIV-1 are associated with platelets during all stages of infection. Platelet-associated HIV could either mediate virus clearance or facilitate virus dissemination and expanded tropism. Finally, virus inactivation research must address virus associations with platelets. 相似文献