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Inhibition of the migration of human prostate cancer PC-3 cells by a series of 18 conformationally flexible and constrained bis(2,6-dioxopiperazine)s including selected bis(morpholinomethyl) derivatives was investigated in vitro using the Matrigel invasion assay. The anti-invasion effects were compared to the cytotoxic effects of these experimental drugs. The parent conformationally mobile ICRF-159 (razoxane) and its dextrorotatory isomer ICRF-187 (dexrazoxane) inhibited invasion at concentrations that were at least 19-fold lower than their cytotoxic concentrations. This indicates that the anti-invasion effect was achieved independent of cytotoxicity. Seven conformationally constrained compounds were found to have no appreciable anti-invasive activity. Generally, the morpholinomethyl pro-drug derivatives of seven of the dioxopiperazines, exhibited either anti-invasive or cytotoxic activities that were reduced or unchanged relative to the parent molecules. In summary, certain bis(2,6-dioxopiperazine)s exhibit a promising and selective anti-invasion effect in human prostate cells. This activity seems to require a flexible linker allowing for multiple conformational possibilities of the dioxopiperazine rings. 相似文献
96.
Nonhereditary p53 mutations in T-cell acute lymphoblastic leukemia are associated with the relapse phase 总被引:2,自引:0,他引:2
We have previously reported that greater than 60% of human leukemic T- cell lines possess mutations in the p53 tumor suppressor gene. To determine whether T-cell acute lymphoblastic leukemia (T-ALL) patient samples possess p53 mutations, we screened peripheral blood-and bone marrow-derived leukemia samples, taken at diagnosis and at relapse, for p53 mutations. Exons 4 through 9 and selected intron regions of the p53 gene were analyzed using polymerase chain reaction-single-strand conformation polymorphism and direct sequencing. p53 mutations were found in 0 of 15 T-ALL diagnosis samples, as compared with 10 of 36 (28%) T-ALL relapse samples. To determine whether p53 mutations play a role in the recurrence (relapse) of T-ALL, two special groups of T-ALL patients were studied: (1) a group of 8 relapse patients whose disease was refractory to chemotherapeutic treatment, and (2) a group of 6 "paired" T-ALL cell samples from patients for whom we possess both diagnosis and relapse samples. Three of 8 relapsed patients (37.5%) whose disease was refractory to the reinduction of remission by chemotherapy possessed missense mutations of the p53 gene. All 3 cases had mutations in exon 5. Among the paired samples, 3 of 6 patients harbored p53 mutations at disease recurrence, but possessed only wild- type p53 alleles at diagnosis. One case had mutation on exon 4, 1 case in exon 5, and 1 case in exon 8 with loss of heterozygosity. These data clearly indicate that recurrence of T-ALL is associated with missense mutations in p53. Our results indicate that (1) mutations of p53 do occur in T-ALL in vivo, and such mutations are associated with the relapse phase of the disease; and (2) p53 mutation is involved in the progression of T-ALL. This conclusion is supported by our observation that the introduction of T-ALL-derived mutant p53 expression constructs into T-ALL cell lines further increases their growth rate in culture, enhances cell cloning in methylcellulose, and increases tumor formation in nude mice. 相似文献
97.
Stephens T 《Diagnostic imaging》1994,(Z1):TA15-TA18
98.
The consequences of disclosure: one hospital's response to the presence of an HIV-positive physician
Stephens BJ Sinden PG Ketcham RH Rzepkowski N 《Hospital & health services administration》1995,40(4):457-471
Health care administrators are having to confront the many and complex problems associated with patient fears about the transmissibility of the HIV virus. Particularly acute are concerns that are raised when the physicians are HIV-positive or have AIDS. This article presents a case history of how one hospital handled the problems created by the announcement by one of its emergency room physicians that he was HIV-positive. The hospital's response--which included disclosure to the community, the full cooperation of the physician, provision of free counseling, and HIV testing--and the aftermath of this AIDS-related event are described. This case is discussed in relationship to the ongoing debate about the ethics and consequences of disclosure of the HIV status of health care workers. 相似文献
99.
Cervical secretory immunoglobulin A in adolescent girls. 总被引:5,自引:0,他引:5
J M Ellen C J Lammel M A Shafer E Teitle J Schachter R S Stephens 《The Journal of adolescent health》1999,25(2):150-154
PURPOSE: To determine whether there are differences in levels of cervical secretory immunoglobulin A (sIgA) between adolescent girls in the secretory and proliferative phases of their menstrual cycle. METHODS: Sexually active adolescent girls (n = 117) at health maintenance organization (HMO) based adolescent medical clinic were recruited into the study. In addition to demographic and clinical data, cervical specimens were collected for sIgA measurement and gonorrhea culture, urine for chlamydia ligase chain reaction, and blood for progesterone levels. Subjects were classified as being in the proliferative phase or secretory phase of the menstrual cycle on the basis of their progesterone levels. RESULTS: The mean age of the subjects was 17.2 years old. There was no difference in the sIgA levels between those in the proliferative phase of their cycle (n = 45; mean sIgA level, 0.0055 mg/mL) and those in the secretory phase (n = 40; mean sIgA level, 0.0032 mg/mL) (p > .10). CONCLUSIONS: The secretory phase of the menstrual cycle does not appear to be associated with higher levels of sIgA in adolescent girls. These results suggest that adolescents with anovulatory cycles, i.e., those who lack a secretory phase, may not be at increased risk for genital tract infections such as chlamydia or gonorrhea. 相似文献
100.
Assessing the laryngeal cough reflex and the risk of developing pneumonia after stroke 总被引:7,自引:0,他引:7
Addington WR Stephens RE Gilliland K Rodriguez M 《Archives of physical medicine and rehabilitation》1999,80(2):150-154
OBJECTIVE: To determine the effectiveness of a new reflex cough test, using nebulized tartaric acid, in the evaluation of the laryngeal cough reflex and the development of aspiration pneumonia. STUDY DESIGN: In this two-phase study, the cough test assessed the cough reflex in 161 stroke subjects. Phase 1 was a double-blinded prospective study of 40 subjects scheduled to have both modified barium swallow and the reflex cough test. Phase 1 subjects with an abnormal cough test showed an increased pneumonia incidence, and therefore, phase 2 was not blinded. In phase 2, 121 subjects were evaluated using the cough test; 38 received a modified barium swallow. Test results were compared using the Fisher exact test. RESULTS: A total of 131 subjects from both phases had a normal reflex cough test; none developed pneumonia (p < .01). Thirty subjects from both phases had abnormal reflex cough test results; 5 developed pneumonia. Modified barium swallow findings did not reliably indicate the risk for developing pneumonia. Specificity of a normal reflex cough test was 100%. CONCLUSION: The reflex cough test reliably evaluated the laryngeal cough reflex and the associated risk of developing aspiration pneumonia in stroke patients. Testing the laryngeal cough reflex may significantly reduce morbidity, mortality, and costs in stroke patients. 相似文献