A new time and space resolved transmission spectrometer for research in inertial confinement fusion and radiation source development.

We describe the design and function of a new time and space resolved x-ray spectrometer for use in Z-pinch inertial confinement fusion and radiation source development experiments. The spectrometer is designed to measure x-rays in the range of 0.5-1.5 Å (8-25 keV) with a spectral resolution λ/Δλ ∼ 400. The purpose of this spectrometer is to measure the time- and one-dimensional space-dependent electron temperature and density during stagnation. These relatively high photon energies are required to escape the dense plasma created at stagnation and to obtain sensitivity to electron temperatures ≳3 keV. The spectrometer is of the Cauchois type, employing a large 30 × 36 mm2, transmissive quartz optic for which a novel solid beryllium holder was designed. The performance of the crystal was verified using offline tests, and the integrated system was tested using experiments on the Z pulsed power accelerator.

Compact, rugged in-chamber transmission spectrometers (7-28 keV) for the Sandia Z facility.

We describe a pair of time-integrated transmission spectrometers that are designed to survey 7-28 keV (1.9 to 0.43 Å) x-ray photons produced by experiments on the Sandia Z pulsed power facility. Each spectrometer uses a quartz 10-11 crystal in a Cauchois geometry with a slit to provide spatial resolution along one dimension. The spectrometers are located in the harsh environment of the Z vacuum chamber, which necessitates that their design be compact and rugged. Example data from calibration tests and Z experiments are shown that illustrate the utility of the instruments.

Evaluation of nursing care after diagnostic coronary angiography.

BACKGROUND: Restricting inpatients who have undergone a cardiac catheterization to 6 hours of flat bed rest to reduce the potential for bleeding from the femoral arteriotomy site is based on tradition rather than on research and is associated with discomfort for the patients. OBJECTIVES: To (1) determine the prevalence of femoral arteriotomy complications after diagnostic coronary angiography among inpatients after implementation of a guideline that included reduced duration of bed rest, elimination of sandbags at the arteriotomy site, and 30 degrees elevation of the head of the bed; (2) compare complication rates in this study with rates in previous studies; and (3) determine patient- or practice-related characteristics associated with complications. METHODS: Records of 306 inpatients were reviewed retrospectively to determine the prevalence of femoral arteriotomy complications and the presence of patient- or practice-related characteristics potentially associated with complications. Associations between each characteristic and the presence of a complication were evaluated by using the Wilcoxon rank sum test for continuous data and the chi 2 or Fisher exact test for nominal data. RESULTS: Prevalences of complications were hematoma, 8.8%; bleeding, 4.5%; pseudoaneurysm, 1%; arteriovenous fistula, 0%; and thrombosis, 0%. No evidence indicated that the occurrence of a complication was related to any patient- or practice-related characteristic. Complication rates were comparable to those of previous studies. CONCLUSIONS: The findings support continuation of the current guideline for patients' care after diagnostic coronary angiography. However, further prospective studies with larger samples of inpatients are warranted.

Genetic analysis of a papillary thyroid carcinoma in a patient with MEN1.

BACKGROUND: MENI is an inherited tumor syndrome characterized by the development of tumors of the parathyroid, the anterior pituitary and the pancreatic islets. Tumors of these endocrine glands in MEN1 patients demonstrate loss of heterozygosity (LOH) at the locus of the MEN1 tumor suppressor gene. Menin, the protein encoded by the MEN1 gene, is ubiquitously expressed in endocrine tissue, and less commonly these patients can present with tumors of other endocrine tissues, including thyroid and adrenal. We hypothesize that MEN1 gene mutation may be involved in the oncogenesis of other less common tumors. METHODS: We report a MEN1 patient who was found to have metastatic papillary thyroid cancer at the time of neck exploration for hyperparathyroidism. Genetic analysis of tumor tissue was performed using one intragenic (D11S4946) and two flanking (D11S4945 and D11S4940) polymorphic markers. RESULTS: Two of the markers were informative. Consistent with previous studies, there was LOH in the parathyroid adenoma identified with the intragenic marker D11S4946. However, the papillary cancer was found to be heterozygous at two informative markers. CONCLUSIONS: The lack of obvious LOH of the MEN1 locus in the papillary cancer suggests that, in contrast to parathyroid adenoma, deletion of the MEN1 tumor suppressor gene is not etiologically related to the oncogenesis of the papillary cancer in this patient.

Genomic structure of the promoters of the human estrogen receptor-alpha gene demonstrate changes in chromatin structure induced by AP2gamma.

Expression of human estrogen receptor-alpha (ERalpha) involves the activity from several promoters that give rise to alternate untranslated 5' exons. However, the genomic locations of the alternate 5' exons have not been reported previously. We have developed a contig map of the human ERalpha gene that includes all of the known alternate 5' exons. By using S1 nuclease and 5'- rapid amplification of cDNA ends, the cap sites for the alternate ERalpha transcripts E and H were identified. DNase I-hypersensitive sites specific to ERalpha-positive cells were associated with each of the cap sites. A DNase I-hypersensitive site, HS1, was localized to binding sites for AP2 in the untranslated region of exon 1 and was invariably present in the chromatin structure of ERalpha-positive cells. Overexpression of AP2gamma in human mammary epithelial cells generated the HS1-hypersensitive site. The ERalpha promoter was induced by AP2gamma in mammary epithelial cells, and trans-activation was dependent upon the region of the promoter containing the HS1 site. These results demonstrate that AP2gamma trans-activates the ERalpha gene in hormone-responsive tumors by inducing changes in the chromatin structure of the ERalpha promoter. These data are further evidence for a critical role for AP2 in the oncogenesis of hormone-responsive breast cancers.

AP2alpha and AP2gamma: a comparison of binding site specificity and trans-activation of the estrogen receptor promoter and single site promoter constructs.

The AP2 transcription factors exhibit a high degree of homology in the DNA binding and dimerization domains. In this study, we methodically compared the binding specificity of AP2alpha and AP2gamma using PCR-assisted binding site selection and competitive gel shift assay and determined that the consensus binding site for both factors is(G)/(C)CCNN(A/)C(/G)(G)/(A)G(G/)C(/T.)The use of single site promoter constructs with either a high or low affinity site demonstrated a direct relationship between site affinity and transcriptional activation. Overexpression of AP2alpha and AP2gamma resulted in the activation of a low affinity binding site construct to levels comparable to those seen with a high affinity site construct at lower amounts of protein expression. Both AP2alpha and AP2gamma were able to trans-activate the cloned human estrogen receptor alpha promoter in ER-negative MDA-MB-231 cells through high affinity AP2 sites in the untranslated leader sequence. This provides a functional mechanism to explain the correlation between AP2 activity and estrogen receptor expression in breast cancer. Since there is overexpression of AP2 factors in breast cancer compared to normal breast epithelium, our results suggest that increased factor expression may activate a set of target genes containing lower affinity binding sites that would normally not be expressed in normal breast epithelium.

Identification of two estrogen receptor transcripts with novel 5' exons isolated from a MCF7 cDNA library.

Two novel transcripts of human estrogen receptor (ER) have been identified that differ in the 5' untranslated sequence. It has previously been determined that an alternate ER transcript is generated from transcription initiated upstream of the main ER cap site (P1), and utilizes a splice acceptor site at +163. Here we report the isolation of 21 ER clones from a MCF7 cDNA library. Eleven of these clones correspond to transcripts that initiate at the P1 cap site, whereas the remaining 10 clones are derived from two previously unidentified ER transcripts (designated E and H) that both utilize the +163 splice acceptor site. A panel of breast and endometrial carcinoma cell lines were screened by reverse transcriptase-polymerase chain reaction (RT-PCR) for expression of the E and H transcripts. It was found that all ER-positive cell lines expressed both of the novel transcripts. In addition, 10 primary human breast cancers were analyzed, of which six expressed the E transcript and five abundantly expressed the H transcript. These data indicate that expression of ER in human breast cancers can be dependent upon an alternate promoter at least 20 kb upstream of the primary cap site for ER.

Identification of ERF-1 as a member of the AP2 transcription factor family.

The ERF-1 transcription factor was previously shown to be involved in the regulation of estrogen receptor (ER) gene transcription in hormonally responsive breast and endometrial carcinomas. In this study we sought to identify the gene for ERF-1. ERF-1 activates ER gene transcription by binding to the imperfect palindrome CCCTGCGGGG within the promoter of the ER gene. ERF-1 protein was purified from the ER-positive breast carcinoma cell line, MCF7, utilizing ion exchange and DNA affinity chromatography. Peptide sequence analysis was used to isolate a 2.7 kb cDNA clone from an MCF7 cDNA library. This cDNA encodes a protein of 48 kDa previously identified as the AP2gamma transcription factor. By gel-shift analysis, in vitro synthesized ERF-1 comigrates with MCF7 native ERF-1 complex and demonstrates identical sequence binding specificity as native ERF-1. In addition, AP2 polyclonal antisera supershifts both in vitro synthesized and native ERF-1 complexes. These results show that ERF-1 is a member of the AP2 family of developmentally regulated transcription factors. Given the central role of ER expression in breast carcinoma biology, ERF-1 is likely to regulate expression of a set of genes characteristic of the hormonally-responsive breast cancer phenotype.

Transcriptional regulation of estrogen receptor in breast carcinomas.

An important transcriptional regulatory element of the estrogen receptor (ER) gene that binds a protein expressed in ER-positive breast carcinomas has been identified. Using a transient expression assay, we identified a 75-bp region of the 5' untranslated leader of the ER gene which augments expression from the ER promoter. This region contains two binding sites for a protein, estrogen receptor factor 1 (ERF-1), which is expressed in ER-positive breast carcinomas. A concatenated ERF-1 binding site probe identified a 30,000-Da protein. Low-level ERF-1 expression was detected in normal human mammary epithelial cells. Abundant ERF-1 expression was also found in endometrial carcinoma cell lines that express the ER-positive phenotype. These results indicate that ERF-1 expression represents a common mechanism of ER regulation in hormonally responsive carcinomas.

Localization of stress protein-70 in ovine corpora lutea during prostaglandin-induced luteolysis.

Accumulation of heat shock (stress) protein-70 (HSP-70) was assessed in corpora lutea of sheep obtained after in vivo administration of a luteolytic dose of prostaglandin (PG) F2 alpha. A quantitative immunofluorescence technique was used to localize inducible HSP-70 production to specific cell-types. The number and intensity of immunostained large luteal cells increased within 2 h of injection of PGF2 alpha. A drop in luteal progesterone concentrations (functional regression) was not manifested until 4 h post-treatment. A dramatic increase in intensely-stained mononuclear leukocytes was observed in luteal tissues at 16 h, when glandular weights had begun to diminish (structural regression). Stress proteins could mediate intracellular protein processing and cell-surface autoimmune mechanisms underlying luteal regression.

Blood flow and relative tissue PO2 of brain and muscle: effect of various gas mixtures.

The effects of inspiring low O2 or high CO2, or low-O2-high-CO2 gas mixtures on tissue perfusion and tissue Po2 of brain and muscle were studied in 76 anesthetized rats. Under control conditions, relative tissue Po2 of cerebral white matter measured polarographically averaged 16.4 mmHg and 18.7 mmHg in the biceps brachii. With low-O2 gas mixtures, tissue Po2 declined in both brain and muscle, but more in muscle. Tissue Po2 increased under high-CO2 conditions, with the brain increasing to a greater extent. Control cerebral cortex tissue perfusion averaged 23.5 ml/min per 100 g and muscle was 18.3 ml/min per 100 g measured by H2 clearance. Brain perfusion increased under all experimental conditions. Muscle perfusion did not change with low O2 alone, but increased with low-O2-high-CO2 or high-CO2 gas mixtures. Brain perfusion increased under all conditions significantly more than muscle. The brain appeared better protected compared to skeletal muscle in terms of tissue Po2 and perfusion under the stress of hypoxia and hypoxic-hypercapnia. The effects of hypercapnia are also greater on the brain.