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291.
292.
AM Krieg T Wu R Weeratna SM Efler L Love-Homan L Yang AK Yi D Short HL Davis 《Canadian Metallurgical Quarterly》1998,95(21):12631-12636
Unmethylated CpG dinucleotides in particular base contexts (CpG-S motifs) are relatively common in bacterial DNA but are rare in vertebrate DNA. B cells and monocytes have the ability to detect such CpG-S motifs that trigger innate immune defenses with production of Th1-like cytokines. Despite comparable levels of unmethylated CpG dinucleotides, DNA from serotype 12 adenovirus is immune-stimulatory, but serotype 2 is nonstimulatory and can even inhibit activation by bacterial DNA. In type 12 genomes, the distribution of CpG-flanking bases is similar to that predicted by chance. However, in type 2 adenoviral DNA the immune stimulatory CpG-S motifs are outnumbered by a 15- to 30-fold excess of CpG dinucleotides in clusters of direct repeats or with a C on the 5' side or a G on the 3' side. Synthetic oligodeoxynucleotides containing these putative neutralizing (CpG-N) motifs block immune activation by CpG-S motifs in vitro and in vivo. Eliminating 52 of the 134 CpG-N motifs present in a DNA vaccine markedly enhanced its Th1-like function in vivo, which was increased further by the addition of CpG-S motifs. Thus, depending on the CpG motif, prokaryotic DNA can be either immune-stimulatory or neutralizing. These results have important implications for understanding microbial pathogenesis and molecular evolution and for the clinical development of DNA vaccines and gene therapy vectors. 相似文献
293.
Accidental and operative trauma are able to induce a systemic reaction of the organism characterized by fever, leukocytosis, catabolism, and an activation of the coagulation system. Interleukin-6 (IL-6) has been found to be an important mediator of this acute-phase response. In this study the influence of elective craniotomy on IL-6 plasma levels was evaluated. Blood samples were obtained from 20 patients undergoing elective craniotomy for vascular or tumorous diseases of the brain. IL-6 increased significantly (p < 0.05) from the pre-operative (0(0-5.4) pg/ml) to the intraoperative (180 min after beginning of surgery) time-point (10.6 (0-18.5) pg/ml). The maximum was reached on the first postoperative morning (13.9(4.3-45.0) pg/ml). Interleukin-10 (IL-10) is an anti-inflammatory cytokine which suppresses IL-6 synthesis in vitro in various cell lines. IL-10 plasma concentrations showed no alterations throughout the study period. Epinephrine plasma concentrations increased significantly from pre-operative values (15 (0-74) pg/ml) to the postoperative time-point (57(9-459) pg/ml). A 4.5-fold increase (p < 0.05) of norepinephrine plasma concentrations was found when comparing the data obtained 60 min after beginning of surgery with the data of the first postoperative morning. In monocytes, which are a major source of plasma IL-6, an elevation of intracellular cAMP stimulates the IL-6 synthesis. The postoperative maximum of IL-6 in plasma could be due to a release of catecholamines. In conclusion this study demonstrated an elevation of IL-6 plasma concentrations during and after elective craniotomy. Increased plasma catecholamine concentrations as well as a damage in the blood-brain barrier due to the surgical trauma with a spill-over of IL-6 from brain tissue into plasma could have contributed to this result. 相似文献
294.
GS Sidhu D Thaloor AK Singh PN Raghunath RK Maheshwari 《Canadian Metallurgical Quarterly》1996,169(1):108-114
OBJECTIVES: We sought to determine the utility of left ventricular expansion velocities in differentiating constrictive pericarditis from restrictive cardiomyopathy. BACKGROUND: Several studies have shown that left ventricular diastolic expansion is influenced by the elastic recoil forces of the myocardium. These forces are affected by intrinsic myocardial disease but should be preserved when diastole is impaired as a result of extrinsic causes. METHODS: Using Doppler tissue imaging, we measured peak early velocity of longitudinal axis expansion (Ea) in 8 patients with constrictive pericarditis, 7 patients with restriction and 15 normal volunteers. Transmitral early (E) and late (A) Doppler flow velocities, left ventricular systolic and diastolic volumes, ejection fraction and mitral annular M-mode displacement were also compared between the groups. RESULTS: The Ea value was significantly higher in normal subjects (14.5 +/- 4.7 cm/s [mean +/- SD]) and in patients with constriction (14.8 +/- 4.8 cm/s) than in those with restriction (5.1 +/- 1.4 cm/s, p < 0.001 constriction vs. restriction). There was weak correlation between Ea and the extent of annular displacement (r = 0.55, p = 0.004) and the E/A ratio (r = 0.44, p = 0.03). There was no correlation between Ea and E (r = 0.33, p = 0.07) or ejection fraction (r = 0.21, p = 0.26). By multivariate analysis, Ea was the best variable for differentiating constriction from restriction. CONCLUSIONS: Our study indicates that longitudinal axis expansion velocities are markedly reduced in patients with restrictive cardiomyopathy. The poor correlation found with transvalvular flow velocities suggests that Ea may be relatively preload independent. The measurement of longitudinal axis expansion velocities provides a clinically useful distinction between constrictive pericarditis and restrictive cardiomyopathy and may prove to be valuable in the study of diastolic function. 相似文献
295.
PURPOSE: We studied the effects of electrical stimulation on idiopathic detrusor instability. MATERIALS AND METHODS: Between January 1993 and December 1994, 30 men and 41 women (mean age plus or minus standard deviation 48 +/- 16 years) underwent transcutaneous electrical nerve stimulation (TENS) of the S2-S3 dermatomes, and 13 men and 22 women (mean age 48 +/- 12 years) underwent S3 neuromodulation. Subjective assessment was performed using a diary and symptom score of 0 to 14. Objective outcome was analyzed with urodynamic studies. RESULTS: Mean duration of TENS was 3 +/- 1 weeks (range 2 to 4). Although there were no major complications 31% of the patients reported local skin irritation. The overall urinary symptom scores improved from 10 +/- 2 (range 5 to 14) before the study to 7 +/- 3 (range 1 to 14) during stimulation. Urodynamic analysis revealed significant (p < 0.05) improvements in total bladder capacity and voided volume, and decreases in the number and frequency of unstable contractions. Mean duration of S3 neuromodulation was 6 +/- 1 days (range 4 to 8 days). Four procedures failed due to electrode displacement in 3 cases and procedure intolerance in 1. Hemorrhage from the puncture site occurred in 1 patient. Overall urinary symptom scores were 10 +/- 3 (range 5 to 14) before the study and 5 +/- 2 (range 2 to 10) during stimulation. Although symptomatic relief was more pronounced with S3 neuromodulation, no statistically significant differences were found regarding urinary symptoms compared to TENS. CONCLUSIONS: In patients with severe detrusor instability refractory to conservative treatments the use of TENS and S3 neuromodulation produced significant changes in urodynamic parameters and presenting symptoms. Our results appear to justify evaluation with neuromodulatory techniques before definitive surgical intervention in these patients. 相似文献
296.
297.
298.
AM Abu el-Asrar AK al-Momen S al-Amro AG Abdel Gader KF Tabbara 《Canadian Metallurgical Quarterly》1996,20(4):197-204
BACKGROUND: The etiology of retinal venous occlusion in young patients is not well understood although thrombosis does occur histologically. A search for the risk factors that may lead to thrombosis is highly desirable may contribute to our understanding of the pathogenesis of this complication and may improve our therapeutic strategies. METHODS: We studied 17 patients with retinal venous occlusion. All patients were under 45 years of age (mean 37.8 +/- 7.1). Antiphospholipid antibodies (APAs) and certain hemostatic factors were determined. The results obtained in these patients were compared to those of normal controls. RESULTS: We found APAs in 8 out of 17 patients compared to 5 out of 60 controls (p = 0.0002). In patients with major trunk occlusion, there was a trend for the presence of APAs in those with poor visual acuity at presentation. Deficiencies of the coagulation inhibitor proteins C and S and antithrombin III activities were detected in 6 patients, and reduced levels of Factor XII were found in 4 patients. Levels of hematocrit, erythrocyte sedimentation rate. Fibrinogen, alpha 1-globulin, and alpha 2-globulin were significantly higher in patients compared to the controls (p = 0.019; 0.014; 0.0001; 0.011; 0.047), indicating increased blood viscosity in patients with retinal venous occlusion. CONCLUSION: Prothrombotic changes in the form of APAs and/or deficiencies of coagulation inhibitors and Factor XII may contribute to the etiology of retinal venous occlusion in young adults. Young patients with retinal venous occlusion should be evaluated for these prothrombotic states. 相似文献
299.
PURPOSE: Only five percent of all patients with ulcerative colitis develop primary sclerosing cholangitis. T cells accumulate at the sites of the colonic and bile duct inflammation in both ulcerative colitis and primary sclerosing cholangitis. T helper cell populations comprise functionally distinct subsets characterized by the cytokines they produce. Several alterations in cytokine production have been described in patients with ulcerative colitis. The aim of this study was to investigate possible differences in T helper subsets and cytokine production in peripheral blood and colonic mucosa among ulcerative colitis patients with and without primary sclerosing cholangitis. METHODS: Eleven patients with primary sclerosing cholangitis and extensive ulcerative colitis, 11 patients with extensive ulcerative colitis and no liver disease, and 5 patients without any history of liver disease who underwent routine colonoscopy because of previous polypectomy were included in the study. Colonoscopy with multiple biopsies was performed on all patients. Lamina propria mononuclear cells and peripheral blood mononuclear cells were isolated. A modified version of solid-phase enzyme-linked immunospot assay was used for the separate counting of cells producing interferon-gamma, interleukin-2 (T helper 1), and interleukin-4 (T helper 2). RESULTS: No differences in spontaneous production of cytokines from peripheral blood mononuclear cells was found among the three groups. Patients with primary sclerosing cholangitis compared with patients with ulcerative colitis without liver disease showed a significant increase in the number of cells secreting interferon-gamma after purified protein derivative stimulation (P < 0.02). More cells secreting interferon-gamma were found in the two ulcerative colitis groups than in the cell populations from healthy controls (P < 0.03). The number of cells secreting interferon-gamma in the primary sclerosing cholangitis group was significantly lower than in the ulcerative colitis group without liver disease (P < 0.04). The number of cells secreting interleukin-4 was lower in the primary sclerosing cholangitis group than among the patients with ulcerative colitis only (P = 0.05). CONCLUSION: Isolated lymphocytes from colonic mucosa differ in cytokine production in patients with ulcerative colitis with and without primary sclerosing cholangitis. 相似文献
300.
AK Kennedy A Guhathakurta N Kleckner DB Haniford 《Canadian Metallurgical Quarterly》1998,95(1):125-134
Nijmegen breakage syndrome (NBS) is a rare autosomal recessive disorder characterized by microcephaly, a birdlike face, growth retardation, immunodeficiency, lack of secondary sex characteristics in females, and increased incidence of lymphoid cancers. NBS cells display a phenotype similar to that of cells from ataxia-telangiectasia patients, including chromosomal instability, radiation sensitivity, and aberrant cell-cycle-checkpoint control following exposure to ionizing radiation. A recent study reported genetic linkage of NBS to human chromosome 8q21, with strong linkage disequilibrium detected at marker D8S1811 in eastern European NBS families. We collected a geographically diverse group of NBS families and tested them for linkage, using an expanded panel of markers at 8q21. In this article, we report linkage of NBS to 8q21 in 6/7 of these families, with a maximum LOD score of 3.58. Significant linkage disequilibrium was detected for 8/13 markers tested in the 8q21 region, including D8S1811. In order to further localize the gene for NBS, we generated a radiation-hybrid map of markers at 8q21 and constructed haplotypes based on this map. Examination of disease haplotypes segregating in 11 NBS pedigrees revealed recombination events that place the NBS gene between D8S1757 and D8S270. A common founder haplotype was present on 15/18 disease chromosomes from 9/11 NBS families. Inferred (ancestral) recombination events involving this common haplotype suggest that NBS can be localized further, to an interval flanked by markers D8S273 and D8S88. 相似文献