27 research outputs found
The Hamburg/SAO Survey for Emission--Line Galaxies. IV. The Fourth List of 119 Galaxies
We present the fourth list with results of the Hamburg/SAO Survey for
Emission-Line Galaxies (HSS hereafter, SAO - Special Astrophysical Observatory,
Russia). The list is a result of the follow-up spectroscopy conducted with the
6m SAO RAS telescope in 1998, 1999 and 2000. The data of this snap-shot
spectroscopy survey confirmed 127 emission-line objects out of 176 observed
candidates and allowed their quantitative spectral classification. We could
classify 76 emission-line objects as BCG/HII galaxies or probable BCGs, 8 - as
QSOs, 2 - as Seyfert galaxies, 2 - as super-associations in a subluminous
spiral and an irregular galaxy, and 37 as low-excitation objects - either
starburst nuclei (SBN), or dwarf amorphous nuclei starburst galaxies (DANS). We
could not classify 2 ELGs. Furthermore, for 5 galaxies we did not detect any
significant emission lines. For 91 emission-line galaxies, the redshifts and/or
line intensities are determined for the first time. Of the remaining 28
previously known ELGs we give either improved data on the line intensities or
some independent measurements. The candidates were taken from three different
samples selected by different criteria. Among our first priority candidates we
achieved a detection rate of emission-line objects (ELGs + QSOs) of 68%, among
which 51% are BCGs. Observations of a random selected sample among our second
priority candidates showed that only ~10% are BCGs. We found that the confirmed
BCGs have usually a blue colour ((B-R) < 1.0) and a non-stellar appearance in
the APM database. Our third sample is comprised of second priority candidates
fulfilling these criteria derived from the APM. Follow-up spectroscopy of a
small subsample indicates that the expected detection rate for BCGs is ~40%.Comment: 15 pages, 1 embedded figure and A1-A12(spectra), A&AS in press.
PS-file of A1-A12(spectra) also available via
http://precise.sao.ru/Laboratory/Publications/2000/HSSIV_figs.ps.g
The Hamburg/SAO Survey for Emission--Line Galaxies. V. The Fifth List of 161 Galaxies
We present the fifth list with results of the Hamburg/SAO Survey for
Emission-Line Galaxies (HSS therein, SAO -- Special Astrophysical Observatory,
Russia). The list is a result of follow-up spectroscopy conducted with the 2.2m
CAHA and 4m Kitt Peak telescopes in 1999. The data of this snap-shot
spectroscopy survey confirmed 166 emission-line objects out of 209 observed
candidates and allowed their quantitative spectral classification and redshift
determination. We could classify 98 emission-line objects as BCG/HII galaxies
or probable BCGs, 5 -- as QSOs, 3 - as Seyfert galaxies, 2 - as
super-associations in subluminous spiral galaxies. 25 low-excitation objects
were classified as starburst nuclei (SBN), 24 as dwarf amorphous nuclei
starburst galaxies (DANS) and 3 as LINERs. Due to low signal-to-noise ratio we
could not classify 6 ELGs. Furthermore, for another 4 galaxies we did not
detect any significant emission lines. For 131 emission-line galaxies, the
redshifts and/or line intensities are determined for the first time. For the
remaining 30 previously known ELGs we give either improved data of the line
intensities or some independent measurements.Comment: 18 pages, A&A in press. Figures A1-A17 (spectra) available in
GIF-format. PS-file with Figures A1-A17 available via
http://precise.sao.ru/Laboratory/Publications/2001/HSSV_figs.ps.g
Coordinate Regulation of Lipid Metabolism by Novel Nuclear Receptor Partnerships
Mammalian nuclear receptors broadly influence metabolic fitness and serve as popular targets for developing drugs to treat cardiovascular disease, obesity, and diabetes. However, the molecular mechanisms and regulatory pathways that govern lipid metabolism remain poorly understood. We previously found that the Caenorhabditis elegans nuclear hormone receptor NHR-49 regulates multiple genes in the fatty acid beta-oxidation and desaturation pathways. Here, we identify additional NHR-49 targets that include sphingolipid processing and lipid remodeling genes. We show that NHR-49 regulates distinct subsets of its target genes by partnering with at least two other distinct nuclear receptors. Gene expression profiles suggest that NHR-49 partners with NHR-66 to regulate sphingolipid and lipid remodeling genes and with NHR-80 to regulate genes involved in fatty acid desaturation. In addition, although we did not detect a direct physical interaction between NHR-49 and NHR-13, we demonstrate that NHR-13 also regulates genes involved in the desaturase pathway. Consistent with this, gene knockouts of these receptors display a host of phenotypes that reflect their gene expression profile. Our data suggest that NHR-80 and NHR-13's modulation of NHR-49 regulated fatty acid desaturase genes contribute to the shortened lifespan phenotype of nhr-49 deletion mutant animals. In addition, we observed that nhr-49 animals had significantly altered mitochondrial morphology and function, and that distinct aspects of this phenotype can be ascribed to defects in NHR-66– and NHR-80–mediated activities. Identification of NHR-49's binding partners facilitates a fine-scale dissection of its myriad regulatory roles in C. elegans. Our findings also provide further insights into the functions of the mammalian lipid-sensing nuclear receptors HNF4α and PPARα
Fat accumulation in Caenorhabditis elegans is mediated by SREBP homolog SBP-1
Research into the metabolism of fats may reveal potential targets for developing pharmaceutical approaches to obesity and related disorders. Such research may be limited, however, by the cost and time involved in using mammalian subjects or developing suitable cell lines. To determine whether invertebrates could be used to carry out such research more efficiently, we investigated the ability of Caenorhabditis elegans (C. elegans) to accumulate body fat following the consumption of excess calories and the mechanisms it uses to metabolize fat. C. elegans worms were grown on media containing various sugars and monitored for changes in body fat and expression of sbp-1, a homolog of the mammalian transcription factor SREBP-1c, which facilitates fat storage in mammals. The fat content increased markedly in worms exposed to glucose. In situ analysis of gene expression in transgenic worms carrying the GFP-labeled promoter region of sbp-1 revealed that sbp-1 mRNA was strongly expressed in the intestine. An sbp-1 knockdown caused a reduction in body size, fat storage, and egg-laying activity. RT-PCR analysis revealed a considerable decrease in the expression of fatty acid synthetic genes (including elo-2, fat-2, and fat-5) and a considerable increase of starvation-inducible gene acs-2. Normal egg-laying activity and acs-2 expression were restored on exposure to a polyunsaturated fatty acid. These findings suggest that SBP-1 and SREBP regulate the amount and composition of fat and response to starvation in a similar manner. Thus, C. elegans may be an appropriate subject for studying the metabolism of fats
Is it advisable to perform preoperativelaryngoscopy in all patients due to undergo the thyroid and parathyroid surgery?Analysis of 5172 preoperative laryngoscopies
Given the yearly growth of thyroid and parathyroid surgery, diagnosis of such serious complications as paresis of the larynx is still relevant today. Endoscopic laryngoscopy is the main method of controlling laryngeal function. The timely detection of violations of this function in the postoperative period allows for patients to be sent to specialists quickly for treatment. Nonetheless, the role of laryngoscopies in the preoperative period has not been precisely recognized. The main contentious issue has become the need to perform preoperative laryngoscopies on all patients due to undergo operations on the thyroid or parathyroid glands.For this paper, we analyzed 5172 consecutive endoscopic laryngoscopies. The role of preoperative laryngoscopy when planning surgery on the thyroid or parathyroid glands was determined.
Aim: to evaluate the feasibility of performing routine laryngoscopies on patients due to undergo surgery for diseases of the thyroid and parathyroid glands.
Materials and Methods.
This paper presents an analysis of the results of preoperative laryngoscopy on 5172 patients who underwent surgical procedures on the thyroid and parathyroid glands.
Results.
Preoperative one-sided paresis of the larynx was detected in 12 (0.23%) of the 5172 patients. Patients did not exhibit bilateral paresis of the larynx.
Conclusions.
Preoperative paresis of the larynx is rare, and performing routine endoscopic laryngoscopies on all patients due to undergo thyroid or parathyroid gland operations is not appropriate