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551.
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Surgery is the recommended and most effective means of preventing the recurrence of primary spontaneous pneumothorax (PSP). However, the conventional belief amongst most clinicians is that surgery should not be routinely offered to patients with an uncomplicated first episode of PSP. The view that surgery should be reserved for recurrent episodes of ipsilateral PSP is based on an apprehension regarding traumatic thoracic surgery combined with a perception that recurrences after a single episode of PSP are unlikely. Modern advances in minimally invasive thoracic surgery have now dramatically reduced the morbidity of PSP surgery. Such surgery is now safe, effective and causes minimal indisposition for patients. On the other hand, modern clinical data suggests that recurrence rate of PSP is perhaps much higher than previously assumed, with more than half of patients experiencing a second episode within several years of the first. With such new appreciations of the current situation, it is appropriate to now consider offering surgery to patients even after the first episode of PSP. 相似文献
553.
CW Bassim JT Wright JP Guadagnini R Muralidharan J Sloan DL Domingo CP Venditti TC Hart 《Oral diseases》2009,15(3):196-205
Introduction and objective: To characterize enamel defects in patients with methylmalonic acidemia (MMA) and cobalamin (cbl) metabolic disorders and to examine salivary methylmalonate levels in MMA.
Subjects and methods: Teeth from patients ( n = 32) were evaluated for enamel defects and compared with age- and gender-matched controls ( n = 55). Complementation class ( mut , cblA , cblB and cblC ) and serum methylmalonate levels were examined. Primary teeth from two patients were examined by light and scanning electron microscopy and salivary methylmalonate levels from two patients were analyzed.
Results: Enamel defects were significantly more prevalent per tooth in the affected group than the control group, across complementation types ( P < 0.0001). The mut MMA subgroup had a significantly higher prevalence per individual of severe enamel defects than controls ( P = 0.021), and those with enamel defects exhibited higher serum methylmalonate levels than those without ( P = 0.017). Salivary methylmalonate levels were extremely elevated and were significantly higher than controls ( P = 0.002). Primary teeth were free of enamel defects except for two cblC patients who exhibited severe enamel hypoplasia. One primary tooth from a cblC patient manifested markedly altered crystal microstructure.
Conclusion: Enamel anomalies represent a phenotypic manifestation of MMA and cbl metabolic disorders. These findings suggest an association between enamel developmental pathology and disordered metabolism. 相似文献
Subjects and methods: Teeth from patients ( n = 32) were evaluated for enamel defects and compared with age- and gender-matched controls ( n = 55). Complementation class ( mut , cblA , cblB and cblC ) and serum methylmalonate levels were examined. Primary teeth from two patients were examined by light and scanning electron microscopy and salivary methylmalonate levels from two patients were analyzed.
Results: Enamel defects were significantly more prevalent per tooth in the affected group than the control group, across complementation types ( P < 0.0001). The mut MMA subgroup had a significantly higher prevalence per individual of severe enamel defects than controls ( P = 0.021), and those with enamel defects exhibited higher serum methylmalonate levels than those without ( P = 0.017). Salivary methylmalonate levels were extremely elevated and were significantly higher than controls ( P = 0.002). Primary teeth were free of enamel defects except for two cblC patients who exhibited severe enamel hypoplasia. One primary tooth from a cblC patient manifested markedly altered crystal microstructure.
Conclusion: Enamel anomalies represent a phenotypic manifestation of MMA and cbl metabolic disorders. These findings suggest an association between enamel developmental pathology and disordered metabolism. 相似文献
554.
555.
Park LS; Waldron PE; Friend D; Sassenfeld HM; Price V; Anderson D; Cosman D; Andrews RG; Bernstein ID; Urdal DL 《Blood》1989,74(1):56-65
Recombinant human granulocyte-macrophage (GM) colony-stimulating factor (GM-CSF), G-CSF, and interleukin-3 (IL-3) labeled with 125I were used to study the characteristics and distribution of receptors for these factors on in vitro cell lines and on cells from patients with acute nonlymphocytic leukemia (ANL) and acute lymphocytic leukemia (ALL). Receptors for GM-CSF and G-CSF were restricted to a subset of myelomonocytic cell lines whereas IL-3 receptors were also found on pre- B- or early B-cell lines. Receptors for all three CSFs were broadly distributed on ANL cells, with considerable variability in levels of expression. Measurement of the colony-forming ability of ANL cells in response to the CSFs showed that there was no direct correlation between the ability of the cells to respond to a growth factor and the absolute number of receptors expressed for that growth factor. Binding of radiolabeled IL-3 and GM-CSF to ANL cells produced complex biphasic curves. Further analysis showed that both IL-3 and GM-CSF were able to partially compete for specific binding of the heterologous radiolabeled ligand to cells from several ANL patients, suggesting that heterogeneity may exist in human CSF receptors. These results provide new insights into the complex role that CSFs may play in ANL. 相似文献
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557.
A constitutively activated chimeric cytokine receptor confers factor- independent growth in hematopoietic cell lines 总被引:3,自引:1,他引:2
The high-affinity receptor for granulocyte-macrophage colony- stimulating factor (GMR) comprises at least 2 distinct subunits, alpha and beta common (beta c), whereas the normal erythropoietin receptor (nEpoR) comprises only one known subunit. An arginine to cysteine (R129C) mutation of the extracytoplasmic domain of the murine EpoR leads to Epo-independent growth in transduced cells (cEpoR). To investigate the proliferative functions of the cytoplasmic regions of each GMR subunit separately and the potential of the R129C EpoR mutation to induce factor-independent growth through heterologous receptor regions, we constructed four hybrid receptors: the extracellular region of either murine nEpoR or cEpoR linked to the transmembrane and cytoplasmic regions of either the human GMR alpha or beta c subunit (nE alpha, nE beta, cE alpha, and cE beta). We then expressed them in an interleukin-3-dependent murine cell line, Ba/F3. Expression of nE beta led to Epo-dependent growth, whereas expression of cE beta conferred factor-independent growth. Surprisingly, expression of cE alpha also resulted in factor-independent cell growth, whereas nE alpha did not respond to Epo. Furthermore, the functional hybrid receptors showed Epo-dependent (nE beta) or constitutive (cE alpha and cE beta) tyrosine phosphorylation of the cytoplasmic kinases JAK1 and JAK2. We reasoned that the proliferative signal of cE alpha was transduced either through the alpha tail itself or through an accessory protein such as the endogenous murine beta common subunit (mu beta c). To distinguish these possibilities, the chimeric receptor cE alpha was expressed in the interleukin-2-dependent murine cell line, CTLL-2, that does not express mu beta c. cE alpha did not induce cell growth in CTLL-2; however, when mu beta c was coexpressed with cE alpha in CTLL-2, factor-independent growth was reconstituted. In conclusion, the cytoplasmic domain of the GMR alpha subunit requires a beta chain for transduction of a proliferative signal. Furthermore, the R129C EpoR mutation can constitutively activate heterologous receptors to mediate factor-independent proliferation. 相似文献
558.
Transvenous inferior vena caval filters were placed in 32 patients (21 bird's nest [BN] and 11 Kimray-Greenfield [K-G] filters). Positive contrast cavography was performed before and immediately after filter placement as well as during long-term follow-up studies. In 23 patients, computed tomographic (CT) scanning was also performed; in 10 patients, real-time ultrasound (US) study was used as an adjunct. CT scans of the BN filter showed one case of hemorrhage and one case of air embolism, both of which were not recognized at cavography. CT scanning of the K-G filter demonstrated two cases of deep penetration of the prongs and one large retroperitoneal hematoma. Real-time US scanning played a major role in checking the final position of the filter and in determining its stability during repositioning of the upper prongs of one BN filter. Noninvasive examinations, including CT and US scanning, are valuable adjuncts in immediate and long-term follow-up study of patients with inferior vena caval filters. 相似文献
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560.