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排序方式: 共有229条查询结果,搜索用时 17 毫秒
51.
Epstein DM; Stephenson LW; Gefter WB; van der Voorde F; Aronchik JM; Miller WT 《Radiology》1986,161(2):423-427
Practicing thoracic surgeons were randomly surveyed to evaluate how computed tomography (CT) has influenced the preoperative evaluation of bronchogenic carcinoma. Thirty-six percent of the 529 respondents routinely requested CT and 62% did so selectively. Approximately 40% indicated that CT provided useful information in most cases. Nearly all surgeons (98.7%) do not rely on the identification of enlarged lymph nodes with CT to spare the patient surgical staging; however, 77.5% are influenced by CT results in their staging procedures. Fifty-seven percent reported that a negative CT study eliminates surgical staging entirely unless the patient has a "coin lesion," in which case 75% are willing to proceed directly to thoracotomy. For surgeons who use CT selectively, an abnormal mediastinal contour on the radiograph was the most frequent radiologic abnormality to prompt CT (85%). Thirty-seven percent are influenced by tumor histology in their decision to request CT. There was little difference in the pattern of CT use between university and community hospital surgeons. 相似文献
52.
Papillary carcinoma of the male breast is very rare. In this case report, we describe the cytologic, histologic, immunohistochemical, and radiological findings of a papillary carcinoma of male breast. A 67-yr-old man, who had a previous history of prostatic adenocarcinoma, presented with a retroareolar painless mass. There was no known history of breast cancer in his family. A fine-needle aspiration biopsy (FNAB) was performed. Cytological examination revealed a cellular aspirate with three-dimensional papillary clusters. A diagnosis of papillary lesion favoring papillary carcinoma was rendered. Immunohistochemical staining of the cell-block of the FNAB revealed the presence of mammaglobin, and the absence of prostatic specific antigen. The patient underwent lumpectomy, which showed a moderately differentiated infiltrating papillary carcinoma with adjacent areas of ductal carcinoma in situ. FNAB is a useful technique in identifying male breast carcinoma. In conjunction with ancillary studies, this procedure can effectively differentiate between a primary versus metastatic lesion. 相似文献
53.
Checchi F Cox J Balkan S Tamrat A Priotto G Alberti KP Guthmann JP 《Emerging infectious diseases》2006,12(10):1477-1485
Quantitative data on the onset and evolution of malaria epidemics are scarce. We review case studies from recent African Plasmodium falciparum epidemics (Kisii and Gucha Districts, Kenya, 1999; Kayanza Province, Burundi, 2000-2001; Aweil East, southern Sudan, 2003; Gutten and Damot Gale, Ethiopia, 2003-2004). We highlight possible epidemic risk factors and review delays in epidemic detection and response (up to 20 weeks), essentially due to poor case reporting and analysis or low use of public facilities. Epidemics lasted 15-36 weeks, and patients' age profiles suggested departures from classical notions of epidemic malaria everywhere but Burundi. Although emergency interventions were mounted to expand inpatient and outpatient treatment access, we believe their effects were lessened because of delays, insufficient evaluation of disease burden, lack of evidence on how to increase treatment coverage in emergencies, and use of ineffective drugs. 相似文献
54.
Genotypes of glutathione transferase M1 and P1 and their significance for lung DNA adduct levels and cancer risk 总被引:21,自引:16,他引:21
Ryberg D; Skaug V; Hewer A; Phillips DH; Harries LW; Wolf CR; Ogreid D; Ulvik A; Vu P; Haugen A 《Carcinogenesis》1997,18(7):1285-1289
The A-G polymorphism at codon 104 in the glutathione S-transferase P1
(GSTP1) gene was examined in 138 male lung cancer patients and 297 healthy
controls. The patients had significantly higher frequency of the GG
genotype (15.9%) and a lower frequency of AA (38.4%) than the controls
(9.1% and 51.5%, respectively). The level of hydrophobic DNA- adducts were
determined in lung tissue from 70 current smokers. Patients with the GG
genotype had a significantly higher adduct level than patients with AA
(15.5 +/- 10.2 vs 7.9 +/- 5.1 per 10(8) nucleotides, P = 0.006). We also
analyzed the deletion polymorphism in the GSTM1 gene in 135 male patients
and 342 controls. The patients were stratified according to histology,
smoking dose, age, adduct level and mutational types found in the tumors
(Ki-ras and p53 genes). The results consistently indicated that the GSTM1
null genotype was associated with a slightly increased lung cancer risk.
When the combined GST M1 and P1 genotypes were examined, patients with the
combination null and AG or GG had significantly higher adduct levels than
all other genotype combinations (P = 0.011). The distribution of combined
genotypes was also significantly different in cases and controls, mainly
due to increased frequency of the combination GSTM1 null and GSTP1 AG or GG
among patients.
相似文献
55.
56.
Evidence for a multipotential stem cell disease in some childhood Philadelphia chromosome-positive acute lymphoblastic leukemia 总被引:2,自引:0,他引:2
Children with Philadelphia chromosome (Ph+) acute lymphoblastic leukemia (ALL) have a poorer prognosis than do most pediatric patients with ALL. Because of this poor prognosis and the presence of the Ph chromosome, we have asked whether or not Ph + ALL involves a multipotential stem cell. We cultured hematopoietic progenitors from two children with Ph+ ALL and examined individual BFU-E and CFU-GM colonies for the Ph chromosome. We studied cells from two patients after 18 to 34 months of first complete clinical remission; direct cytogenetic analyses showed 26% and 13% Ph+ metaphases in these patients' marrow cells. BFU-E colonies were obtained from light density marrow cells cultured in methylcellulose supplemented with erythropoietin and CFU-GM colonies from agar or methylcellulose cultures stimulated with leukocyte feeder layers. Fifty-seven G-banded metaphases were recovered from 33 colonies. Ten metaphases from seven colonies were Ph+. Ph+ metaphases were found in three of 12 and three of five BFU-E colonies from the two patients. One of 16 CFU-GM colonies from one patient had the Ph+ chromosome; analyzable metaphases were not obtained from CFU-GM of the other patient. No colonies contained both Ph+ and Ph- cells. These results indicate that Ph+ ALL with persistence of Ph+ cells in remission involves a multipotential stem cell for erythroid and granulocyte/macrophage as well as lymphoid lineages. Multipotential stem cell involvement in the pathogenesis of some childhood Ph+ ALL suggests similarities to Ph+ chronic myelocytic leukemia and may contribute to the poor prognosis of these patients. 相似文献
57.
Scandella D; Gilbert GE; Shima M; Nakai H; Eagleson C; Felch M; Prescott R; Rajalakshmi KJ; Hoyer LW; Saenko E 《Blood》1995,86(5):1811-1819
The finding that human factor VIII (fVIII) inhibitor antibodies with C2 domain epitopes interfere with the binding of fVIII to phosphatidylserine (PS) suggested that this is the mechanism by which they inactivate fVIII. We constructed a recombinant C2 domain polypeptide and demonstrated that it bound to all six human inhibitors with fVIII light chain specificity. Thus, some antibodies within the polyclonal anti-light chain population require only amino acids within C2 for binding. Recombinant C2 also partially or completely neutralized the inhibitor titer of these plasmas, demonstrating that anti-C2 antibodies inhibit fVIII activity. Immunoblotting of a series of C2 deletion polypeptides, expressed in Escherichia coli, with inhibitor plasmas showed that the epitopes for human inhibitors consist of a common core of amino acid residues 2248 through 2312 with differing extensions for individual inhibitors. The epitope of inhibitory monoclonal antibody (MoAb) ESH8 was localized to residues 2248 through 2285. Three human antibodies and anti-C2 MoAb NMC-VIII/5 bound to a synthetic peptide consisting of amino acids 2303 through 2332, a PS- binding site, but MoAb ESH8 did not. These antibodies also inhibited the binding of fVIII to synthetic phospholipid membranes of PS and phosphatidylcholine, confirming that the blocked epitopes contribute to membrane binding as well as binding to PS. In contrast, MoAb ESH8 did not inhibit binding. As the maximal function of activated fVIII in the intrinsic factor Xase complex requires its binding to a phospholipid membrane, we propose that fVIII inhibition by anti-C2 antibodies is related to the overlap of their epitopes with the PS-binding site. MoAb ESH8 did not inhibit fVIII binding to PS-containing membranes, suggesting the existence of a second mechanism of fVIII inhibition by anti-C2 antibodies. 相似文献
58.
Effect of platelet-activating factor (PAF) on human platelets 总被引:7,自引:0,他引:7
The effect of pure synthetic PAF (1-0-alkyl-2-acetyl-sn-glycero-3- phosphorylcholine) was studied in human platelets. PAF (0.2--2.0 micrograms/ml) produced a dose-dependent aggregation in human platelet- rich plasma (PRP) or platelet suspension obtained by gel-filtration (GFP). In addition, PAF (0.8 microgram/ml) induced secretion of 14C- serotonin (45% +/- 10%; mean +/- SD, n = 9) and platelet factor 4 (PF4) (12.89 +/- 3.81 micrograms/10(9) platelets; n = 9) in PRP. Similar results were obtained in GFP. Aggregation and release of 14C-serotonin and PF4 were inhibited by the metabolic inhibitors 2-deoxyglucose (16.7 mM) and antimycin-A (8.3 micrograms/ml), by the membrane-active drugs mepacrine (10 microM) and chlorpromazine (0.025 mM), by PGI2 (5.34 nM), which elevates intracellular c-AMP, by indomethacin (10 microM) or aspirin (100 microM). The ADP scavengers, creatine phosphate and creatine phosphokinase (CP/CPK), inhibited the second wave of aggregation but not secretion. These data suggest that the major effect of PAF on human platelets is mediated through the cyclo-oxygenase pathway and not through a third pathway. 相似文献
59.
We studied the relationship of direct karyotypes, determined at diagnosis and remission, to Abelson-related tyrosine kinase activity and the cytogenetic features of erythroid and myeloid colonies derived from remission marrow of six children with acute lymphoblastic leukemia (ALL). These patients had either the characteristic Philadelphia chromosome (Ph1) [t(9;22)(q34;q11)] or cytogenetically similar variants with a 22q11 breakpoint but no detectable cytogenetic involvement of 9q34. The findings suggested two distinct subtypes of ALL: one defined by t(9;22)(q34;q11) and expression of P185BCR-ABL tyrosine kinase and one with variant karyotypes and no P185BCR-ABL expression. The former comprises cases with Ph1 + marrow cells and Ph1 + erythroid and (or) myeloid colonies in remission marrow and others in which the t(9;22) is undetectable in remission marrow cells. In the latter subgroup, the disease may reflect more extreme mosaicism with a similar stem cell that is cytogenetically undetectable. Variant karyotypes included a del(22)(q11) in one patient and a t(6;22;15;9) (q21;q11;q?22;q21) in another; in both instances, the malignant blast cells lacked P185BCR- ABL expression. Thus ALL with t(9;22)(q34;q11) should be distinguished from ALL with other involvement of the 22q11 breakpoint by molecular studies including protein expression. The diversity of karyotypic findings in cases with involvement of 22q11 suggests at least two mechanisms of leukemogenesis in patients with ALL defined by this breakpoint. 相似文献
60.
The factor VIII complex: structure and function 总被引:30,自引:1,他引:30
Normal human plasma contains a complex of two proteins that are important in hemostasis and coagulation. The factor VIII procoagulant protein (antihemophilic factor) and the factor VIII-related protein (von Willebrand factor) are under separate genetic control, have distinct biochemical and immunologic properties, and have unique and essential physiologic functions. While the nature of their interaction and the details of the biochemical structures remain to be determined, the information now available permits a preliminary understanding of the molecular defects in hemophilia and von Willebrand's diseases. 相似文献