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81.
Human lymphocytes and Chinese hamster ovary (CHO) cells in culture were exposed for 12 1/2 hours to a magnetic resonance imaging apparatus with a 2.35-Tesla magnet and 100-MHz radio frequency emission. The cells were examined for cytogenetic damage manifested either as chromosome aberrations or sister chromatid exchanges (SCEs), which constitute very sensitive measures of genetic and cellular damage. In either unstimulated or stimulated human lymphocytes, as well as in exponentially growing CHO cells, no increase in either chromosome aberrations or SCEs was found as a result of exposure to these MR conditions. The data indicate that long-term exposure to MR imaging conditions far exceeding those to be found in the clinical situation does not cause cytogenetic damage. 相似文献
82.
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85.
X-linked syndrome of platelet dysfunction, thrombocytopenia, and imbalanced globin chain synthesis with hemolysis 总被引:6,自引:5,他引:1
An unusual family is described with a congenital bleeding disorder present in four males belonging to three generations. Of the three surviving affected males, all had splenomegaly and petechiae. The three had moderate thrombocytopenia (55-90 X 10(9)/liter) and markedly prolonged Ivy-template bleeding times (greater than 30 min). They were also noted to have reticulocytosis and, upon further investigation, imbalanced globin chain synthesis resembling that of beta-thalassemia minor. Studies on nine additional family members in four generations were normal except for slight elevations of reticulocyte counts in female members, one of whom had the abnormal globin chain synthesis ratio. In male members, the bleeding tendency and clinical signs always occurred in the presence of the globin chain synthesis defect and reticulocytosis. This previously undescribed condition was apparently transmitted as an X-linked disorder. 相似文献
86.
Cuello C; Palladinetti P; Tedla N; Di Girolamo N; Lloyd AR; McCluskey PJ; Wakefield D 《Rheumatology (Oxford, England)》1998,37(7):779-783
OBJECTIVE: To investigate the expression and source of chemokines in minor
salivary gland biopsies (MSGs) in patients with Sjogren's syndrome (SS).
METHODS: Immunohistochemical analysis was used to determine the pattern of
chemokine expression in MSGs from patients with (n=6) and without (n=5) SS,
as well as to examine the phenotype of both resident and infiltrating cells
expressing chemokines. RESULTS: Significant differences in the number of
infiltrating mononuclear (MN) cells in patients with and without SS were
noted. Ductal epithelial cells of SS biopsies expressed significantly
increased levels of macrophage inflammatory protein (MIP)-1alpha,
MIP-1beta, interleukin-8 (IL-8) and RANTES (Regulated upon Activation,
Normal T cell Expressed and Secreted). Biopsies from patients with SS
showed that MIP-1beta was expressed by 51% of infiltrating cells, while 41%
expressed MIP-1alpha, whereas 22 and 7% expressed RANTES and IL-8,
respectively. CONCLUSION: Chemokines expressed by ductal epithelial cells
may attract circulating leucocytes, in particular CD4+ T cells, towards the
site of inflammation, thereby orchestrating the influx of MN cells
characteristically seen in MSGs in SS. Chemokines may be induced directly
by a putative triggering agent for SS, or secondary to the release of
pro-inflammatory cytokines produced by epithelial cells. These findings
further implicate epithelial cells as playing a major role in the
pathogenesis of SS and implicate chemokines in the leucocyte recruitment in
this setting.
相似文献
87.
88.
Spinning top urethra (STU) is a term used to describe a widened posterior urethra seen mainly in girls. It is commonly regarded as a normal variant. The authors studied 30 girls with STU using videourodynamics. Twenty-eight showed bladder instability; 21, a congenital wide bladder neck anomaly; and 20, both instability and a wide bladder neck. One patient had a sensitive bladder. All patients had a urodynamic abnormality. The authors believe that the STU is nearly always an indication of bladder instability or wide bladder neck anomaly. The most common mechanism for the dilatation of the posterior urethra is that unstable contractions are resisted by a voluntary increase in distal sphincter tension so as to prevent leakage of urine. The resulting pressure rise produces distention of the posterior urethra, which will be maximal in subjects with a weak bladder neck mechanism as in the congenital wide bladder neck anomaly. The authors believe that STU is seldom if ever a normal variant. 相似文献
89.
The platelet release reaction was studied by a new quenched-flow approach. Platelets labeled with 14C-serotonin were reacted for short times (up to 5 sec) with thrombin and then quenched with glutaraldehyde or paraformaldehyde. Serotonin secretion began within 1 sec and was nearly complete by 4 sec. Aggregation recorded by a resistive-particle counter was similarly fast. Therefore, the quenched-flow system reveals that serotonin secretion can occur more rapidly than estimated in earlier studies. 相似文献
90.
Donald Coggan 《Journal of medical ethics》1977,3(2):57-60
The idea of a happy death is one that startles and disgusts modern man. However, although that phrase is not often used today, that is what the Archbishop of Canterbury, Dr Donald Coggan, is to some extent considering in his Edwin Stevens lecture given to the Royal Society of Medicine. We are publishing extracts from that lecture by kind permission of the President of the Royal Society of Medicine. We have chosen those passages in the lecture which discuss the limits of the doctor's responsibility to keep a patient alive, the erroneous idea that Christians believe in the artificial prolongation of life in all circumstances, and the most delicate question of the choice of patients who shall receive the costly benefits of modern medical technology. 相似文献