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1.
We grafted fetal thymi from wild-type mice into immunodeficient RAG-2-/- or class II-/-RAG-2-/- (class II MHC-) recipients and followed the fate of naive CD4+ T cells derived from the grafts. In both types of recipients, newly generated CD4+ T cells proliferated to the same extent in the periphery and rapidly filled the empty T cell compartment. However, CD4+ T cells in class II- recipients gradually decreased in number over 6 months. These results show that interactions between the TCR and class II molecules are not required for newly generated CD4+ T cells to survive and proliferate, but are necessary to maintain the size of the peripheral T cell pool for extended periods.  相似文献   

2.
It is the desire of every dentist and dental technician to produce a restoration that will fit the patient with a minimum of adjustments and certainly one that does not require remaking. Yet many abuse the materials with which they work, either through improper manipulation, lack of familiarity with their properties, or by attempting to reduce laboratory time by taking short cuts. Wax is one of the materials that requires more knowledge and skill to manipulate accurately because it has a considerably higher coefficient of thermal expansion (and contraction) than any other dental material. It often contributes considerably to the inaccuracies of cast dental restorations. This article provides a review of dental waxes used to make prosthodontic castings and points out some of the properties of waxes that must be controlled to make accurate restorations.  相似文献   

3.
3H-labelled oestradiol-17beta and 14C-progesterone were injected i.v. into an adult female Sumatran rhinoceros (Dicerorhinus sumatrensis) and all urine and faeces collected over 4 days. Of the injected steroid, 68% of 3H-oestradiol and 89% of 14C-progesterone were recovered. Peak excretion in urine occurred on day 1 for both steroids, and for faeces on day 2 for 14C-progesterone, and between days 2 and 3 for 3H-oestradiol. Oestradiol metabolites were predominantly (nearly 70%) excreted into the urine, while progesterone metabolites were almost exclusively (> 99%) excreted into the faeces. The majority (> 70%) of urinary excreted oestrogens consisted of water-soluble (i.e., conjugated) forms, with > 90% of these being glucuronides. In contrast, > 75% of faecal oestrogen and progesterone metabolites were excreted as ether-soluble (i.e., unconjugated) forms. HPLC co-chromatography of oestrogens in hydrolysed urine indicated only one peak of radioactivity, co-eluting with authentic oestradiol-17beta, whereas two peaks of radioactivity were found after HPLC of faecal oestrogens, the major one co-eluting with oestrone and the less prominent one with oestradiol-17beta. Progesterone was excreted as numerous metabolites into the faeces. The three most abundant of these were identified using HPLC and gas chromatography mass spectrometry (GCMS) as 5beta-pregnane-3alpha,20alpha-diol, 5beta-pregnane-3alpha-ol-20-one, and a second pregnanediol, the exact structure of which could not be deduced. Measurement of urinary oestradiol-17beta and faecal immunoreactive pregnanediol and 5alpha-pregnane-3alpha-ol-20-one in daily samples enabled the first endocrine characterization of the ovarian cycle and indicated a cycle length of approximately 25 days.  相似文献   

4.
The information available concerning the effects of chemotherapy administered during pregnancy is limited and consists of case reports and small series. A registry has been established at the National Cancer Institute, but there are currently only several hundred cases of neonates exposed to chemotherapy registered. All clinicians who care for women receiving chemotherapy during pregnancy should report those experiences to the National Cancer Institute to increase the data base. When chemotherapy is used during the embryogenesis period in the first trimester there is an increased rate of spontaneous abortion and major birth defects. The most toxic chemotherapeutic agents administered during pregnancy are methotrexate and aminopterin and should be avoided when possible, particularly during the first trimester. Pregnancy-related physiologic changes should be kept in mind when dosing and administering cytotoxic chemotherapy. The risk of fetal malformation when chemotherapy is administered during the second and third trimesters is probably not greater than background rate, but there may be a greater risk of stillbirth, fetal growth restriction, premature birth, and maternal and fetal myelosuppression. Breastfeeding should be avoided in women receiving chemotherapy.  相似文献   

5.
After administration of oestradiol-17beta to intact mature and immature rats, a decrease in the testicular concentration of specific oestradiol-binding sites was observed within 1 h. The binding capacity was replenished starting about 3 h after oestradiol administration and after 5 h the oestrogen receptor level had returned to control values. Exposure of intact animals to oestradiol-17beta for longer periods (up to 24 h) did not result in an increase of receptor levels in testicular cytosol. Mature animals which were hypophysectomized for periods of up to 10 days did not show a significant change in the number of specific oestradiol-binding sites in either total testicular tissue or dissected interstitial tissue. At 15 days or longer periods after hypophysectomy, an apparent increase in receptor concentrations in total testicular cytosol was observed due to a relative increase in the amount of interstitial tissue. A specific oestradiol-binding protein is present in plasma of immature male rats aged less than 30 days. This plasma protein could also be demonstrated in the cytosol of testes of immature rats. In contrast to the cytosol receptor, which shows a moderate affinity for diethylstilbestrol (DES), the plasma protein did not bind DES. The sedimentation values of the plasma protein and the oestradiol receptor were 4 S and 8 S respectively. These differences in characteristics made it possible to demonstrate the presence of the oestradiol receptor in addition to the binding protein in testicular cytosol of rats from 14 days of age onwards. The nuclear receptor for oestradiol-17beta could be demonstrated after incubation of testicular tissue of rats from 4 days of age onwards.  相似文献   

6.
Nuclear and cytoplasmic exchange assays were developed and validated to quantify receptors for estradiol-17 beta (E217 beta) and progesterone (P4) in hypothalamic and pituitary tissues of gilts before, during, and after treatment with pregnant mare's serum (PMS) and human chorionic gonadotropin (hCG). Prepubertal gilts, 5 months old, were assigned randomly to four treatments. One group of gilts received 500 IU PMS (Day 0) and were sacrificed 2 days later (2 days post-PMS); another group received 500 IU PMS on Days 0 and 2, and were sacrificed 4 days from the initial injection (4 days post-PMS). A third group of gilts received PMS (500 IU) on Days 0 and 2, 1000 IU hCG on Day 4, and were sacrificed 5 days after hCG (5 days post-hCG). Controls were given saline on Days 0, 2 and 4 and sacrificed on Day 6. In pituitary tissues, there were no significant changes in numbers of cytoplasmic E2 17 beta receptors, cytoplasmic P4 receptors, nuclear P4 receptors or nuclear E2 17 beta receptors among the control, 2 days post-PMS, 4 days post-PMS or 5 days post-hCG treatment groups. In hypothalamic tissues, no differences in cytoplasmic E2 17 beta receptors, cytoplasmic P4 receptors or nuclear P4 receptors were found among any of the treatments. Nuclear receptors for E2 17 beta in hypothalamic tissues were greater, however, in gilts 2 days post-PMS (P less than 0.05) than in controls or 5 days post-hCG gilts, but they were not different from gilts 4 days post-PMS. Follicular development and serum concentrations of E2 17 beta followed the expected patterns after PMS; only ovaries from hCG-treated pigs contained corpora lutea. Because the PMS-hCG regimen simulated the onset of puberty, it seems that gilts attain puberty without a significant change in the number of receptors for E2 17 beta and P4 in the pituitary or hypothalamus.  相似文献   

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8.
Work leading to the concept of hormone responsiveness of human breast cancer and current views of the mode of action of oestrogens in target tissues are reviewed. Results of oestrogen receptor assays are considered in relation to clinical response to tumours to endocrine therapy and difficulties encountered in the interpretation of receptor determinations are discussed. Recent work on the distribution of different forms of the oestrogen receptors in human tumours and their relation to clinical response may lead to better selection of patients for endocrine therapy. Results of receptor assays in male patients with breast cancer, in benign breast tumours and in malignant tumours at sites other than breast are reviewed, and work on receptors for hormones other than oestrogens is discussed briefly. Further work is needed on the integrity of the receptor mechanism in tumour cells and on the effects of hormone treatment. Methods for the separation and estimation of oestrogen receptors in human tumour tissue are reviewed and discussed. Errors arising during collection, storage and analysis are considered. Different ways of calculating and expressing results of these assays are mentioned. It is suggested that more accurate determinations of oestrogen receptors may lead to better discrimination between hormone responsive and unresponsive human breast tumours.  相似文献   

9.
This article reports the findings from the second part of a two-stage study that used both qualitative and quantitative methods to investigate the communication context of school-based HIV-AIDS education in state secondary schools in metropolitan and rural areas of New South Wales. The quantitative data are here described, focusing on a sample of 1005 Year 12 students' responses to a self-administered questionnaire. The data suggest that the students strongly supported the general idea of school-based HIV-AIDS education, but found current offerings lacking in several respects. Students identified a strong need for information about how HIV and AIDS affect the body, for more information about sexually transmissible diseases other than HIV-AIDS, for people with HIV themselves and experts in the field to provide education sessions, and for more small-group discussions. Rural students and those students from schools located in the outer western suburbs of Sydney in particular reported that they had insufficient access to the modes of information that they most preferred. There were some important differences between the responses of female and male students and between the responses of students from different ethnic groups, suggesting that these factors also need acknowledgment when school-based programs are designed for young people.  相似文献   

10.
Plasma Oe2 concentration was measured by radioimmunoassay in patients with premature thelarche, with precocious puberty and in 29 normal controls. The mean plasma Oe2 was 1.5 pg/ml (0-7.2) in normal prepubertal girls, 23.8 +/- 17.8 (SD) in pubertal girls, 50.2 (+/- 19.4) in the follicular phase, and 94.2 (+/- 19.5) in the luteal phase of normal adult females. Ten girls with premature thelarche had a mean of 7.7 +/- 6.6 pg/ml. Three of them showed higher values than the other 7, suggesting that in these cases, elevated levels of plasma Oe2 might have played a role in the development of breast tissue. Ten untreated girls with idiopathic precocious sexual development had a mean of 51.6 +/- 42.9 pg/ml while 6 patients treated with 150 mg per week of medroxyprogesterone acetate had a mean of 11.4 +/- 2.5 pg/ml. Two patients with Down's syndrome, hypothyroidism and sexual precocity had plasma Oe2 of 144 and 31.5 which fell to 24.7 and 8 pg/ml, respectively, after thyroid replacement. One girl with a granulosa cell tumour had a basal value of 304 pg/ml and a concentration of 27 pg/ml after surgery.  相似文献   

11.
Galectins (S-type lectins) are a family of low-molecular weight, calcium-independent, mannose-binding lectins with functions in cell growth, cell activation, cell-cell and cell-matrix adhesion including binding to carcinoembryonic antigens and laminin and metalloproteinase. Anti-galectin antisera can inhibit metastases of rat prostate cancers and human melanomas. To define the role of galectins in human breast cancer, the expression of galectin-3 were determined in 27 invasive breast cancers by immunohistochemical methods. The histologic grades of excised breast cancers were determined and immunohistochemical staining for galectin-3 (1: 1000 dilution of anti-galectin rat polyclonal antibody) was defined by scoring the intensity and distribution of staining (0-3+). The mean age of breast cancer patients was 63 years for 20 grade II breast cancers and 56 years for 7 grade III breast cancers. The mean immunohistochemical staining score for grade II breast cancers was 3. 7 (20% less than 2, 80% 3-6) and 2.5 for grade III (71.4% less than 2 and 28.6% 3-6). The galectin-3 expression pattern suggests that increasing histologic grade of breast cancer leads to reduced expression of galectin-3 and possibly reduced matrix binding and increased cancer cell motility.  相似文献   

12.
Retinoic acid inhibits proliferation and steroid receptor gene expression in human breast cancer cell lines. Retinoic acid receptors (RAR)alpha, -beta, and -gamma are expressed in these cells and the expression of RAR alpha is significantly greater in estrogen receptor (ER)-positive cells. This study was undertaken to determine whether the same relationship between RAR alpha and ER gene expression was present in human breast cancers and to explore the possibility that the higher level of RAR alpha in ER-positive cells was due to estrogen regulation of RAR alpha gene expression. RAR alpha and ER mRNA expression were determined by Northern blot analysis in 116 primary breast tumors; 94 (81%) tumors were ER-positive and of these 87 (93%) were also RAR alpha-positive. The coexpression of ER and RAR alpha was statistically significant (P = 0.0052 by chi 2 contingency analysis). There was also a positive correlation (by linear regression analysis) between the levels of expression of ER and RAR alpha mRNA (r2 = 0.251, P = 0.0001), which confirmed the relationship previously documented in breast cancer cell lines and suggested that RAR alpha expression may be modulated in breast cancer in vivo by estrogens acting via the ER. The ability of estradiol to regulate RAR alpha gene expression was examined in vitro using T-47D cells which had been rendered sensitive to estrogen by repeated passage in steroid-depleted medium. Estradiol increased RAR alpha gene expression, but not that of RAR beta or RAR gamma, in a concentration-dependent manner, with the effect being maximal at 10(-10) M and less marked at higher concentrations. The effect was rapid, being detectable 1 h after and maximal 6 h after treatment with 10(-10) M estradiol. Co-treatment of cells with estradiol and antiestrogens (tamoxifen or ICI 164384, 4 x 10(-7) M for 6 h) inhibited the estradiol induction of RAR alpha gene expression, demonstrating that the effect was ER mediated. The estradiol sensitivity of the effect was underscored by the demonstration that addition of untreated serum to cells growing under steroid-depleted conditions was sufficient to induce maximal RAR alpha gene expression. This effect was totally abolished by addition of ICI 164384. In summary, the demonstration that estradiol increased RAR alpha mRNA levels in breast cancer cells supports the hypothesis that the correlation between RAR alpha and ER gene expression in breast tumors and breast cancer cell lines is due to estradiol augmentation of RAR alpha gene expression.  相似文献   

13.
Fistulas between the abdominal aorta and renal vein are exceedingly rare. Diagnostic delays are not unusual. Correction can be extremely difficult because of anatomical distortion and size of the arterialized veins. A young woman with such a fistula following a gunshot wound is presented. Four years following injury, the fistula was repaired successfully during intentional arrest of the circulation for 7 minutes. This was accomplished with deep hypothermia and cardiopulmonary bypass. No serious problems occurred during the operation. The patient tolerated the procedure well and has been relieved of her symptoms completely. Most patients with traumatic or spontaneous arteriovenous fistulas can be managed safely and effectively by conventional operative techniques. In selected situations, the risk of total circulatory arrest and deep hypothermia may be less than the risk of uncontrollable bleeding inherent in conventional techniques. Suggested indications for use of total circulatory arrest in vascular surgery are (1) inability to achieve vascular control by more conventional means, (2) massive distention of regional veins as occurrs in well established fistulas of the trunk, (3) one or more prior corrective attempts with use of conventional techniques, and (4) anticipated anatomical distortion and/or multiple abnormal vascular communications. This technique is a valuable approach to the correction of otherwise inoperable cardiovascular lesions.  相似文献   

14.
Uterine cytosol was prepared from rabbits after treatment with human chorionic gonadotrophin (HCG) and used for the determination of oestradiol-17 beta and oestrone by competitive protein binding (CPB) assay. The so obtained uterine cytosol gave higher percentage of binding and proved to be more stable when stored at --20 degrees C than cytosol obtained from the pregnant uterus.  相似文献   

15.
The Alberta Infant Motor Scale (AIMS) is a norm-referenced measure of infant gross motor development. The objectives of this study were: (1) to establish the best cut-off scores on the AIMS for predictive purposes, and (2) to compare the predictive abilities of the AIMS with those of the Movement Assessment of Infants (MAI) and the Peabody Developmental Gross Motor Scale (PDGMS). One hundred and sixty-four infants were assessed at 4 and 8 months adjusted ages on the three measures. A pediatrician assessed each infant's gross motor development at 18 months as normal, suspicious, or abnormal. For the AIMS, two different cut-off points were identified: the 10th centile at 4 months and the 5th centile at 8 months. The MAI provided the best specificity rates at 4 months while the AIMS was superior in specificity at 8 months. Sensitivity rates were comparable between the two tests. The PDGMS in general demonstrated poor predictive abilities.  相似文献   

16.
To understand the biological significance of progesterone receptor forms A (PR-A) and B (PR-B) in human corpus luteum, the expression of mRNA and serum steroid hormone concentrations were determined simultaneously in the luteal stages. The expression of PR-A mRNA predominated over PR-B mRNA in all samples analysed. Total PR (PR-AB) and PR-B mRNA concentrations at the late secretory phase were significantly (P < 0.01) lower than those at the early and mid secretory phases of the menstrual cycle. The ratio of PR-B to PR-AB mRNA concentration showed no significant change during the secretory phase. In the early and mid secretory phases, there was a negative correlation between PR-B mRNA concentration and serum progesterone concentration, and between the ratio of PR-B to PR-AB mRNA concentrations and serum progesterone concentration (P < 0.01). These findings suggest that human corpus luteum might intracellularly synthesize PR-A and PR-B, and thus be involved in the steroid functional regulation of the corpus luteum, especially at the early and mid secretory phases, and that progesterone might regulate the synthesis of PR-A and PR-B.  相似文献   

17.
Adrenal androgens show a dual and apparently opposite effect on the growth of oestrogen-responsive breast cancer: they stimulate growth on their own, but counteract the growth-stimulatory effect of oestrogens. Focusing on the inhibitory action we have studied the effects of 5-en-androstene-3 beta,17 beta-diol (ADIOL) on the growth of oestrogen-responsive MCF-7 breast cancer cells in the presence of oestrogens (oestradiol and diethylstilboestrol), antiestrogens (tamoxifen) and antiandrogens (hydroxyflutamide). The inhibition of oestrogen-stimulated growth, attained with nanomolar concentrations of ADIOL, was not modified by increasing concentrations of diethylstilboestrol up to 100 nM. This inhibition was counteracted by antiandrogens, which were unable to block the ADIOL stimulatory effect in steroid-free medium. On the other hand, in the presence of tamoxifen ADIOL showed an additive antiproliferative activity also in steroid-free medium, rather than the usual stimulatory effect. These results suggest that ADIOL stimulates breast cancer cell growth via oestrogen receptors, but inhibits oestrogen-stimulated growth via androgen receptors.  相似文献   

18.
We performed a saturation binding study with 125I-labeled FGF (fibroblast growth factor)-2 in a nonselected series of 250 human primary breast cancers. Two hundred twenty-five breast cancer biopsies possessed bFGFR (basic FGF receptor). The median dissociation constant was 0.35 nM (range, 0.014-1.9), and the median concentration was 1126 fmol/mg protein (range, 49-7328). FGFR-1 was localized, using a specific monoclonal antibody, in cancerous cells and in epithelial cells in normal breast or in benign tumors. In all of the tissues studied, light stromal cell staining was also observed. Thus, the localization of FGFR-1 in carcinoma cells supports the hypothesis that an important part of FGF-2 binding reflects binding to FGFR-1. bFGFR concentrations were positively correlated to estrogen receptor and progesterone receptor levels. Cox univariate analyses showed that the bFGFR (> or = upper quartile) was associated to longer relapse-free survival [P = 0.004; RR (risk ratio), 0.46] and overall survival (P = 0.001; RR, 0.35); age, estrogen receptor levels, progesterone receptor levels, node involvement, tumor diameter, and histoprognostic grading were prognostic, also. In Cox multivariate analyses, only the bFGFR, age, node involvement, and histoprognostic grading were prognostic factors; the bFGFR was associated with longer relapse-free survival (P = 0.03; RR, 0.4) and overall survival (P = 0.009; RR, 0.3). The present study confirms that FGF could be an important regulator of human breast cancer growth and that patients with a high level of bFGFR had a better prognosis.  相似文献   

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