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21.
B Davit K Reynolds R Yuan F Ajayi D Conner E Fadiran B Gillespie C Sahajwalla S M Huang L J Lesko 《Journal of clinical pharmacology》1999,39(9):899-910
Recent advances in in vitro metabolism methods have led to an improved ability to predict clinically relevant metabolic drug-drug interactions. To address the relationships of in vitro metabolism data and in vivo metabolism outcomes, the Office of Clinical Pharmacology and Biopharmaceutics in the Center for Drug Evaluation and Research, Food and Drug Administration, evaluated a number of recently approved new drug applications. The goal of these evaluations was to determine the contribution of in vitro metabolism data in (1) predicting in vivo drug-drug interactions, (2) determining the need to conduct an in vivo drug-drug interaction study, and (3) incorporating findings into drug product labeling. Ten cases are presented in this article. They fall into two major groups: (1) in vitro data were predictive of in vivo results, and (2) in vitro data were not predictive of in vivo results. Discussion of these cases highlights factors limiting predictability of in vivo metabolic interactions from in vitro metabolism data. The integration of these findings into drug product labeling is also discussed. 相似文献
22.
Hypospadias trends in two US surveillance systems 总被引:6,自引:0,他引:6
OBJECTIVE: Hypospadias is a common congenital anomaly, the cause of which is unknown. Unexplained increases in the rates of hypospadias occurred in five European countries in the 1970s and 1980s. We examined data from two birth defects surveillance systems in the United States for evidence of similar trends. METHODOLOGY: The Metropolitan Atlanta Congenital Defects Program (MACDP) provided birth prevalence rates from 1968 to 1993. The nationwide Birth Defects Monitoring Program (BDMP) provided rates from 1970 to 1993. MACDP data are population-based and could be categorized by the severity of the hypospadias. BDMP data allowed analysis of rate trends for the four census regions of the United States. RESULTS: Data from both surveillance systems showed an approximate doubling of hypospadias rates in the 1970s and 1980s. MACDP data showed that the rate of severe cases increased while the ratio of mild to severe cases decreased. BDMP data showed that hypospadias rates increased markedly in all four regions of the United States. CONCLUSIONS: The observed increases are unlikely to be attributable to increased sensitivity of the surveillance systems or the identification of more mild cases by physicians over time, because either trend would have increased rather than decreased the ratio of mild to severe cases. If real, these trends represent the largest number of cases and the first report of an increase in hypospadias rates outside of Europe. Additional investigation of a possible increase in hypospadias rates is warranted. 相似文献
23.
Black tea and mammary gland carcinogenesis by 7,12- dimethylbenz[a]anthracene in rats fed control or high fat diets 总被引:3,自引:1,他引:3
Epidemiological studies suggest that tea may reduce cancer risk, and in
laboratory rodents, chemopreventive effects of tea or purified extracts of
tea have been demonstrated in lung, gastrointestinal tract and skin. There
is some evidence of chemoprevention by tea in the mammary gland, but the
data are not conclusive. In order to evaluate more fully the possible
influence of black tea on 7,12-dimethylbenz[a]anthracene (DMBA)-induced
mammary gland tumors in the female S-D (Sprague-Dawley) rat, three large
studies were performed: experiment 1, tumorigenesis in rats fed AIN-76A
diet and given 25 mg/kg DMBA and 1.25 or 2.5% whole tea extract or water to
drink; experiment 2, tumorigenesis in rats given 15 mg/kg DMBA and the same
diet and fluids as in experiment 1; experiment 3, tumorigenesis in rats fed
control or HF (high fat, corn oil) diet and given 15 mg/kg DMBA and 2% tea
or water to drink. Tea was given throughout the experiment; DMBA was given
by gastric gavage at 8 weeks of age. There was no consistent effect of tea
on tumorigenesis in rats fed AIN-76A diet; there was, however, evidence in
experiment 3 of a reduction of tumorigenesis by tea in rats fed the HF
diet. In experiment 3, rats fed the HF diet and given water showed the
expected increase in tumor burden (number and weight) compared with rats
fed control diet. However, rats fed the HF diet and given 2% tea showed no
increase in tumor burden; their tumor burden was significantly lower than
in rats fed the HF diet and given water (P < 0.01) and was not different
from rats fed control diet and given water or tea. In addition, in
experiment 3, the number of malignant tumors per tumor- bearing rat was
increased by the HF diet in water-drinking rats (P < 0.01) but not in
tea-drinking rats. Therefore, it appears that tea partially blocked the
promotion of DMBA-induced mammary tumorigenesis by the HF diet.
相似文献
24.
Zhao P Cao J Zhao LJ Qin ZL Ke JS Pan W Ren H Yu JG Qi ZT 《第二军医大学学报》2006,27(5):506-506
The nucleocapsid (N) protein of SARS-coronavirus (SARS-CoV) is the key protein for the formation of the helical nucleocapsid during virion assembly. This protein is believed to be more conserved than other proteins of the virus, such as spike and membrane glycoprotein. In this study, the N protein of SARS-CoV was expressed in Escherichia coli DHSalpha and identified with pooled sera from patients in the convalescence phase of SARS. A plasmid pCI-N, encoding the full-length N gene of SARS-CoV, was constructed. Expression of the N protein was observed in COS1 cells following transfection with pCI-N. The immune responses induced by intramuscular immunization with pCI-N were evaluated in a murine model. Serum anti-N immunoglobutins and splenocytes proliferative responses against N protein were observed in immunized BALB/c mice. The major immunoglobulin G subclass recognizing N protein was immunoglobulin G2a, and stimulated splenocytes secreted high levels of gamma interferon and IL-2 in response to N protein. More importantly, the immunized mice produced strong delayed-type hypersensitivity (DTH) and CD^8+ CTL responses to N protein. 相似文献
25.
Interruption of the contrast column during inspiration can lead to non‐diagnostic CT pulmonary angiograms. The importance of this artefact will increase with more CT studies being performed for pulmonary embolism on multidetector row CT. We describe here an instance of such an artefact and discuss its aetiology. 相似文献
26.
We report a case of an assisted pregnancy in an asymptomatic woman who was found to have an extrauterine mass on ultrasound and MRI. This complex mass had equivocal imaging features and was found to be a ruptured ovarian ectopic pregnancy at surgery. This case illustrates that vigilance is required regarding the possibility of coexisting ectopic and intrauterine pregnancy following assisted conception, even in entirely asymptomatic cases. 相似文献
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29.
The purpose of this study was to determine the nature and prevalence of the psychological symptomatology in parents of children undergoing bone marrow transplantation (BMT) and to investigate the manner in which certain psychosocial factors are related to parental distress associated with the informed consent process. A total of 61 parents (46 mothers and 15 fathers) were assessed with respect to psychological distress, coping styles, quality of physician-patient communication, and recall of BMT information after providing written consent for their child to have BMT. Forty-seven percent of fathers and 60% of mothers exhibited significant psychological distress of a generalized nature. Mothers exhibited a broader range of specific psychological symptomatology and more severe levels of depression and phobic anxiety than did fathers. The level of parents' distress was unrelated to characteristics of their child's disease or treatment milieu, or to parents' recall of BMT information. However, emotional coping was positively related to psychological distress whereas the quality of the communication between physician and parent was inversely related. The findings from this study suggest that approximately 50% of all parents could benefit from psychological interventions which promote the efficient utilization of coping strategies and highlight the importance of the nature of the communication style used by oncologist-investigators in obtaining informed consent. 相似文献
30.
Using pharmacogenetics-based therapy, clinicians can estimate the therapeutic warfarin dose by genotyping patients for single
nucleotide polymorphisms (SNPs) that affect warfarin metabolism or sensitivity. SNPs in the cytochrome P450 complex (CYP2C9) affect warfarin metabolism: patients who have the CYP2C9*2 and/or CYP2C9*3 variants metabolize warfarin slowly and are more
likely to have an elevated International Normalized Ratio INR or to hemorrhage during warfarin initiation than patients without
these variants. SNPs in vitamin K epoxide reductase (VKORC1) correlate with warfarin sensitivity. Patients who are homozygous for a common VKORC1 promoter polymorphism, −1639 G>A (also designated as VKOR 3673, haplotype A, or haplotype*2), are warfarin sensitive and
typically require lower warfarin doses. By providing an estimate of the therapeutic warfarin dose, pharmacogenetics-based
therapy may improve the safety of anticoagulant therapy. To improve drug safety, the FDA updates labels of previously approved
drugs as new clinical and genetic evidence accrues. The labels of medical products serve to inform prescribers and patients
about potential ways to improve the benefit/risk ratio and/or optimize doses of medical products. On August 16, 2007, the
FDA updated the label of warfarin to include information on pharmacogenetic testing and to encourage, but not require, the
use of this information in dosing individual patients initiating warfarin therapy. The FDA completed the label update in August
2007.
Disclosure: A portion of this article was adapted from an education handout that Dr. Gage has retained copyright of: Gage, B.F. (2006).
Pharmacogenetics-based coumarin therapy. Hematology Am Soc Hematol Educ Program: 467–473. Dr. Gage has served as a consultant
to Bristol-Myers Squibb.
Funding: NIH R01 HL074724. 相似文献