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961.
962.
PURPOSE: To evaluate routine non-contrast material-enhanced helical computed tomography (CT) of the adrenal glands in patients with non-small cell lung carcinoma to facilitate characterization of adrenal masses detected in an unmonitored environment (i.e., the radiologist on duty did not look at the acquired images before the patient left the scanner). MATERIALS AND METHODS: One hundred consecutive patients with non-small cell lung carcinoma were referred for CT evaluation of the chest; chest and abdomen; or chest, abdomen, and brain. All underwent unenhanced CT of the adrenal glands before the requested CT examination. The morphologic features, size, and attenuation values of the adrenal masses were calculated. Attenuation values of adrenal masses from prior imaging, if available, were compared with those at follow-up imaging to classify these masses. Variable unit cost increase in obtaining these additional images was estimated. RESULTS: Fifteen adrenal masses were identified in 13 patients. In one patient, bilateral ill-defined adrenal masses were present. In 12 patients, 13 masses were sharply circumscribed: Seven were less than 10 HU and six were 20 HU or greater at unenhanced CT. Nine of these 12 patients received iodinated contrast material. Without the unenhanced CT, 10 adrenal masses in these nine patients would have been indeterminate for malignancy. In six of these nine patients, the adrenal mass was the only potential site of metastatic disease. The unenhanced CT data helped classify three of these masses as benign-10 HU or less- and three as indeterminate-greater than 10 HU. CONCLUSION: Unenhanced CT of the adrenal glands can prospectively characterize adrenal masses and obviate further examination in patients with lung carcinoma.  相似文献   
963.
Strategies for developing selective water diuretic agents have involved development of kappa opioid receptor agonists and vasopressin V2 receptor antagonists; however, these two classes of compounds have not been compared directly. We have investigated the activity of three kappa receptor agonists and one nonpeptide vasopressin receptor antagonist in conscious dogs. SB 215520, SB 215519 and niravoline are selective kappa agonists with variable abilities to cause a water diuresis and ataxia in rats. When administered to conscious hydropenic dogs, the kappa agonists resulted in an increase in free water clearance; however, these effects were associated with an antinatriuresis, an increase in heart rate and, at the higher doses, central nervous system side effects. Conversely, the vasopressin receptor antagonist, OPC 31260, resulted in a significant water diuresis without any accompanying changes in sodium excretion and heart rate, and with no apparent central nervous system effects. These studies suggest that, at least in dogs, a vasopressin receptor antagonist is a more selective water diuretic than a kappa receptor agonist.  相似文献   
964.
965.
966.
We compared daily T4 therapy with 7 times the normal daily dose administered once weekly in 12 hypothyroid subjects in a randomized cross-over trial. At the end of each treatment we measured serum free T4 (FT4), free T3 (FT3), rT3, and TSH levels and multiple markers of thyroid hormone effects at the tissue level repeatedly for 24 h. Compared with daily administration, the mean serum TSH before the administration of weekly T4 was higher (weekly, 6.61; daily, 3.92 microIU/mL; P < 0.0001), and the mean FT4 (weekly, 0.98; daily, 1.35 ng/dL; P < 0.01) and FT3 (weekly, 208, daily, 242 pg/dL; P < 0.01) were lower. A minimally elevated serum total cholesterol during weekly administration (weekly, 246.8; daily, 232.6 mg/dL; P < 0.03) was the only evidence of hypothyroidism at the tissue level. Compared with daily administration, the mean peak FT4 following weekly administration of T4 was significantly higher (weekly, 2.71; daily, 1.59 ng/dL; P < 0.0001), as was the mean peak FT3 level (weekly, 285; daily, 246 pg/dL; P < 0.01). None of the tissue markers of thyroid hormone effect changed compared to daily T4, and there was no evidence of treatment toxicity, including cardiac toxicity. During weekly T4 administration, autoregulatory mechanisms maintain near-euthyroidism. For complete biochemical euthyroidism a slightly larger dose than 7 times the normal daily dose may be required.  相似文献   
967.
Sixteen chemicals currently being tested in National Toxicology Program (NTP) carcinogenicity studies were evaluated in the Syrian hamster embryo (SHE) cell in vitro micronucleus assay. Results from these studies were compared to the results from the SHE cell transformation assay for the same chemicals The overall concordance between induction of micronuclei and transformation of SHE cells was 56%, which is far lower that the 93% concordance between these two tests reported previously by Fritzenschaf et al. (1993; Mutation Res. 319, 47-53). The difference between our results appears to be due to differences in the types of chemicals in the two studies. Overall, there is good agreement between the SHE cell micronucleus and transformation assays for mutagenic chemicals, but, as our study highlights, the SHE cell transformation assay has the added utility of detecting nonmutagenic carcinogens. The utility of a multi-endpoint assessment in SHE cells for carcinogen screening is discussed.  相似文献   
968.
Primordial germ cells (PGCs) are described from the gonad of c. 2 cm juvenile Branchiostoma virginiae; early oocytes (c. 10 microm) and enlarging, previtellogenic oocytes (c. 35 microm) are described from the ovary of c. 5 cm adults. The germinal epithelium of the juvenile gonad and adult ovary is composed of both germinal and somatic cells. In the juvenile, somatic cells retain contact with the basal lamina of the germinal epithelium though their perikarya may be displaced towards the lumen; the germinal epithelium is, therefore, a simple but pseudostratified epithelium. In the adult ovary, somatic cells may lose contact with the basal lamina and the epithelium appears to become stratified. PGCs and oocytes are identified as germ cells by the presence of nuage. PGCs and oocytes are polarised epithelial cells. They rest on a basal lamina, extend apically towards a lumen, form adhering junctions with neighbouring cells, and exhibit apical-basal polarity. PGCs and early oocytes have an apical flagellum with an associated basal body, accessory centriole, and one or more striated rootlet fibres. The flagellum is surrounded by a collar of microvilli. Once oocytes begin to enlarge and bulge basally into the connective tissue layer, the flagellum is lost, but the basal bodies and ciliary rootlets are present at the apex of 35 microm oocytes. Similarities of the oogenic pattern in cephalochordates and echinoderms indicate that the establishment of egg polarity in deuterostomes is influenced by the polarity of the germinal epithelium.  相似文献   
969.
Cloacal anomalies are extremely rare and have variable presentations. Prenatal diagnosis can be difficult especially if they present in late gestation. Here we present two cases diagnosed in the late third trimester and review the literature regarding prenatal diagnosis of cloacal anomalies.  相似文献   
970.
The 1969 Stonewall riot in New York City is widely celebrated as the beginning of the modern gay rights movement. However, the social changes that followed were possible only because of a decades-long indigenous organization. This article examines three traditional organizational theories on social action movements and applies Aldon Morris's analytical framework for understanding collective social action to the emergence of the modern U.S. gay civil rights movement. The author concludes that social workers need to understand how to gain access to and support indigenous social structures to assist oppressed groups to bring about social change.  相似文献   
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