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21.
Titus K 《CAP today / College of American Pathologists》1996,10(9):1, 52-4, 56-8
22.
23.
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
24.
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
25.
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
26.
Mark A Titus Christopher W Gregory O Harris Ford Michael J Schell Susan J Maygarden James L Mohler 《Clinical cancer research》2005,11(12):4365-4371
PURPOSE: Prostate cancer recurs during androgen deprivation therapy despite reduced circulating androgens. We showed that recurrent prostate cancer tissue has testosterone levels similar to androgen-stimulated benign prostate, whereas dihydrotestosterone levels were reduced 82% to 1.45 nmol/L, sufficient for androgen receptor activation. The altered testosterone/dihydrotestosterone ratio in recurrent prostate cancer suggests loss of 5alpha-reducing capability. The aim of this study was to characterize steroid 5alpha-reductase isozymes I (S5alphaRI) and II (S5alphaRII) in prostate tissues. EXPERIMENTAL DESIGN: A tissue microarray was constructed from 22 recurrent prostate cancer specimens and matched pairs of androgen-stimulated benign prostate and androgen-stimulated prostate cancer from 23 radical prostatectomy specimens. Immunoblots were constructed from eight recurrent prostate cancers, eight androgen-stimulated benign prostate, and eight androgen-stimulated prostate cancer specimens. Isozyme expression was examined in microarray sections and immunoblots using S5alphaRI and S5alphaRII polyclonal antibodies. Isozyme activities were measured in 12 recurrent prostate cancer, 12 androgen-stimulated benign prostate, and 12 androgen-stimulated prostate cancer specimens. RESULTS: Nuclear immunostaining exhibited higher S5alphaRI expression than S5alphaRII in recurrent prostate cancer, androgen-stimulated benign prostate, and androgen-stimulated prostate cancers (P < 0.0001); mean expression was 125, 150, and 115 for S5alphaRI versus 10, 29, and 37 for S5alphaRII, respectively. Cytoplasmic immunostaining was moderate and similar for both isozymes in the three tissue types (P > 0.05). Immunoblots confirmed immunohistochemistry; S5alphaRI was expressed in recurrent prostate cancer specimens and S5alphaRII was not detected. The activity of S5alphaRI (114.4 pmol/mg epithelial protein/minute) was 3.7-fold higher than S5alphaRII (30.7 pmol/mg epithelial protein/minute) in recurrent prostate cancer specimens. CONCLUSIONS: Expression levels and isozyme activity shifts from S5alphaRII toward S5alphaRI in recurrent prostate cancer. Dual inhibition of S5alphaRI and S5alphaRII should reduce dihydrotestosterone biosynthesis and may prevent or delay growth of recurrent prostate cancer. 相似文献
27.
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
28.
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
29.
为了寻找毒性低、增敏作用强的乏氧细胞放射增敏剂,设计并合成了一系列5-溴-,5-甲基-,和5-未取代的3-硝基-1,2,4-三唑-1-乙酰胺类化合物,用HeLaS3细胞进行了体外试验。结果表明5-溴取代衍生物的增敏作用强于相应的5-甲基-或5-未取代的硝基三唑衍生物,但是它们的毒性亦增大。修饰1位乙酰胺侧链也可以改变化合物的增敏作用和亲脂性。在所测定的化合物中TA-101[2-(3-硝基-1-三唑基)乙酰胺]由于有高的增敏作用和低亲脂性,可能是一个有希望的放射增敏剂。 相似文献
30.
Determination of malondialdehyde-induced DNA damage in human tissues using an immunoslot blot assay 总被引:3,自引:4,他引:3
Leuratti C; Singh R; Lagneau C; Farmer PB; Plastaras JP; Marnett LJ; Shuker DE 《Carcinogenesis》1998,19(11):1919-1924
Malondialdehyde (MDA) is a product of lipid peroxidation and prostaglandin
biosynthesis. It is mutagenic and carcinogenic and the major adduct formed
by reaction with DNA, a highly fluorescent pyrimidopurinone (M1-dG), has
been detected in healthy human liver and leukocyte DNA. Analytical methods
used so far for the detection of M1- dG have not been applied to a large
number of individuals or variety of samples. Often, only a few microg of
DNA from human tissues are available for analysis and a very sensitive
assay is needed in order to detect background levels of M1-dG in very small
amounts of DNA. In this paper, the development of an immunoslot blot (ISB)
assay for the measurement of MI-dG in 1 microg of DNA is described. The
limit of detection of the assay is 2.5 adducts per 10(8) bases. A series of
human samples were analysed and levels of 5.6-9.5 (n = 8) and 3.1-64.3 (n =
42) of M1-dG per 10(8) normal bases were detected in white blood cell and
gastric biopsy DNA, respectively. Results on four human samples were
compared with those obtained using an HPLC/32P-post- labelling (HPLC/PPL)
method previously developed and indicated a high correlation between M1-dG
levels measured by the two assays. The advantages of ISB over other assays
including HPLC/PPL, such as the possibility of analysing 1 microg
DNA/sample and the fact that it is less time-consuming and laborious, means
that it can be more easily used for routine analysis of a large number of
samples in biomonitoring studies.
相似文献