| 11. |
- Nilsson, Rickard, et al.
(author)
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Self-synchronizing a DMT-based VDSL system
- 2001
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In: Where minds meet. - Piscataway, NJ : IEEE Communications Society. ; , s. 1249-1253
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Conference paper (peer-reviewed)abstract
- We present an algorithm for self-synchronizing all modems in a discrete multitone (DMT)-based very high-speed digital subscriber line (VDSL) system using the Zipper duplex method. This solves the problem with non-orthogonal near-end crosstalk (NEXT) that appears in systems with unsynchronized modems. The algorithm we present runs autonomously in each VDSL-modem. It uses the auto-correlation of the DMT-signal to determine the frame-offset of other users, and adjusts the own frame-timing to be better aligned with the other users. With our method all modems will be self-synchronized to within a small fraction of the total DMT frame-length. This self-synchronization suppresses the NEXT to a level far below the background noise-floor. This means that our self-synchronized system has the same performance as a system where all modems are perfectly synchronized to a master clock
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| 12. |
- Panagopoulos, Ioannis, et al.
(author)
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RT-PCR analysis of the MOZ-CBP and CBP-MOZ chimeric transcripts in acute myeloid leukemias with t(8;16)(p11;p13)
- 2000
-
In: Genes, Chromosomes and Cancer. - 1045-2257. ; 28:4, s. 415-424
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Journal article (peer-reviewed)abstract
- The translocation t(8;16)(p11;p13) is associated with a subtype of acute monocytic leukemia (AML M5) characterized morphologically by erythrophagocytosis and clinically by a poor prognosis. The t(8;16) fuses the MOZ gene from 8p11 with the CBP (also named CREBBP) gene from 16p13. Previously published studies of MOZ and CBP rearrangements in t(8;16)-positive AML have used fluorescence in situ hybridization and Southern blot methodologies, whereas attempts to amplify and to analyze further the chimeric MOZ-CBP and CBP-MOZ transcripts by means of reverse transcriptase-polymerase chain reaction (RT-PCR) have largely been unsuccessful. In the only t(8;16) that has been described at the sequence level using RT-PCR, the CBP-MOZ fusion was found to be out-of-frame, suggesting that the reciprocal MOZ-CBP transcript is the essential one for leukemogenesis. We have developed an RT-PCR strategy that enables us to detect the MOZ-CBP as well as the CBP-MOZ fusions in the two AML M5 with t(8;16)(p11;p13) analyzed. In both leukemias, the combination of a MOZ forward and a CBP reverse primer amplified a strongly expressed 1,128 bp fragment (type I transcript) and a weakly expressed 415 bp fragment (type II transcript). In the type I transcript, nucleotide (nt) 3,745 of MOZ was fused in-frame with nt 284 of CBP, whereas in the type II transcript, nt 3,745 of MOZ was fused out-of-frame with nt 997 of CBP. Nested PCR with a combination of two forward CBP and two reverse MOZ primers amplified CBP-MOZ chimeric transcripts in both cases. Direct sequence analysis showed that nt 283 of CBP was fused in-frame with nt 3,746 of MOZ, that the initiation ATG codon of the CBP gene remained intact, and that there was no mutation or deletion in the part of the CBP gene included in the CBP-MOZ transcript. Thus, the data we present are not informative with regard to the question whether it is the MOZ-CBP or the CBP-MOZ transcript that is leukemogenic. The present RT-PCR method may be of value for rapid identification of the t(8;16) and also for further molecular genetic studies of the two fusion transcripts and their roles in leukemogenesis.
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| 13. |
- Persson, Anders I., 1973, et al.
(author)
-
Expression of delta opioid receptor mRNA and protein in the rat cerebral cortex and cerebellum is decreased by growth hormone.
- 2003
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In: Journal of neuroscience research. - : Wiley. - 0360-4012 .- 1097-4547. ; 71:4, s. 496-503
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Journal article (peer-reviewed)abstract
- Hormones released from the pituitary have been shown to regulate the expression of different proteins in the central nervous system. We wanted to examine whether peripheral administration of bovine growth hormone (bGH) regulates the expression of delta-opioid receptor (DOR) in the cerebral cortex and cerebellum. Expression of the DOR protein was quantified using Western blot densitometry. DOR mRNA was quantified with a solution hybridization RNase protection assay. Hypophysectomized (Hx) and untreated normal female rats were included in the study. All Hx rats were hormonally treated with cortisol (400 microg/kg/day) and L-thyroxine (10 microg/kg/day) for 19 days. Hypophysectomy resulted in a threefold increase in cerebral cortex and a twofold increase in cerebellum of the DOR protein compared with normal rats. One subgroup of Hx rats received bGH (1 mg/kg body weight) as a daily subcutaneous injection for 19 days. This treatment normalized the levels of DOR protein in the cerebral cortex and cerebellum. Immunohistochemical experiments showed that GH decreased DOR expression especially in layers II-VI in cerebral cortex and in stratum moleculare in cerebellum. Quantification of DOR mRNA by solution hybridization RNase protection assay corresponded to the DOR protein measurements. We conclude that the expression of DORs in cerebral cortex and cerebellum is regulated by GH.
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| 14. |
- Pohjola, V, et al.
(author)
-
Effect of periodic melting on geochemical and isotopic signals in an ice core from Lomonosovfonna, Svalbard
- 2002
-
In: J.Geophys.Res.. ; 107:D4, s. ACL 1-14
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Journal article (peer-reviewed)abstract
- In this work we examine the quality of the atmospherically deposited signals in an ice core taken from a periodically melting ice field, Lomonosovfonna on central Spitsbergen, Svalbard. The aim is to investigate how much the atmospheric deposited signals in the stratigraphy of ice pack are changed by periodic melting of the ice. To determine the impact of this melting on the stratigraphy found in the ice core, we use three diagnostics: 1) Association between peak values in the ice chemical and isotopic record and ice facies type; 2) Number of “annual” cycles in these records compared with independently-determined number of years represented in the ice core; 3) Statistical comparison between the isotopic record in the ice core and the isotope records from coastal stations from the same region. We find that during warm summers as much as 50% of the annual accumulation may melt and percolate into the firn, and in a median year this decreases to ca. 25 %. As a consequence of percolation the most mobile acids show upto 50 % higher concentrations in bubble poor ice facies compared with facies that are less affected by melt. Most of the other chemical species are less affected than the strong acids, and the stable water isotopes show little evidence of mobility Annual, or bi-annual cycles are detected in most parameters, and the water isotope record has a comparable statistical distribution to isotopic records from coastal stations. We conclude that ice cores from sites like Lomonosovfonna preserve an useful environmental record despite melt events and percolation, where most parameters displays an annual, or in poor cases a bi-annual atmospheric signal.
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| 15. |
- Pohjola, V, et al.
(author)
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Reconstruction of three centuries of annual accumulation rates based on the record of stable isotopes of water from Lomonosovfonna, Svalbard
- 2002
-
In: Annals of glaciology. ; 35, s. 57-62
-
Journal article (peer-reviewed)abstract
- We use the upper 81 m of the record of stable isotopes of water from a 122 m long ice core from Lomonosovfonna, central Spitsbergen, to construct an ice core chronology and the annual accumulation rates over the ice field. The isotope cycles are counted in the ice core record using a model that neglects short wavelength and low amplitude cycles. We find approximately the same number of ä18O cycles as years between known reference horizons, and assume these cycles represent annual cycles. Testing the validity of this assumption using cycles in äD shows that both records give similar numbers of cycles. Using the ä18O chronology, and de-compressing the accumulation records using the Nye flow model, we calculate the annual accumulation for the ice core site back to 1715 AD. We find that the average accumulation rate from 1715 to 1950 o was on average 0.30 m w.e. Accumulation rates increased ca. 25% during the later part of the 20th century to an average of 0.41 m w.e. for the period 1950 – 1997. The accumulation rates show highly significant 2.1 and 21 year periodicities, which gives credibility to our time scale.
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| 16. |
- Valdemarsson, Stig, et al.
(author)
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Evaluation of surgery for acromegaly: role of intraoperative growth hormone measurement?
- 2001
-
In: Scandinavian Journal of Clinical & Laboratory Investigation. - : Informa UK Limited. - 1502-7686 .- 0036-5513. ; 61:6, s. 459-470
-
Journal article (peer-reviewed)abstract
- OBJECTIVE: Intraoperative growth hormone (GH ) measurement has earlier been tried to improve surgery for acromegaly. We calculated GH half-life after adenomectomy and evaluated the possible role of this variable in predicting the final outcome of pituitary surgery in 28 consecutive patients with acromegaly. The sensitivity, specificity and predictive values were determined in relation to the results from GH suppression during an oral glucose load and IGF-1 3 months postoperatively. The GH half-life data were also compared to the corresponding results obtained from GH measurements between 60 min and 180 min after adenomectomy, and early, within 1 week, postoperatively. RESULTS: GH half-life < or =31 min was recorded in 8/13 cured patients but also in 2/15 unsuccessful cases. A mean GH concentration < or =4.4 mU/L between 60 min and 120 min after adenomectomy was found in 11/13 cured subjects but also in 3/15 not cured patients. A mean GH < or =4.0 mU/L between 90 min and 180 min was found in 11/13 cured and in 4/15 not cured patients. A mean early postoperative GH concentration < or =2.6 mU/L was noted in all 13 cured patients, but also in 2/13 unsuccessful cases. The specificity of early postoperative GH < or = 2.6 mU/L was 100% compared to 62% for a GH half-life < or =31 min (p<0.05) and 85% for the GH mean values between 60 min and 120 min and 90 min and 180 min, respectively. The sensitivity for persistent disease of values above the four cut-off limits used was between 73% and 87%. The positive predictive value for a mean early postoperative GH value >2.6 mU/L was 100%, and 72% for a GH half-life >31 min (n.s.). CONCLUSION: Although intraoperative GH half-life might be useful in some cases, it was not a reliable tool for predicting outcome of pituitary surgery in acromegaly. In cases with a 51% decrease of a basal GH concentration >5.5 mU/L, mean GH values < or =4 to < or =4.4 mU/L late intraoperatively were more informative but not as good as those obtained from the mean of a series of GH values drawn on one occasion within 1 week postoperatively, offering a 100% specificity for cure if < or =2.6 mU/L. Intraoperative GH half-life measurements should therefore be used with caution. The predictive values of the cut-off limits used in this study should be further evaluated before general application.
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| 17. |
- Wallenius, Kristina, 1973, et al.
(author)
-
Liver-derived IGF-I regulates GH secretion at the pituitary level in mice.
- 2001
-
In: Endocrinology. - 0013-7227. ; 142:11, s. 4762-70
-
Journal article (peer-reviewed)abstract
- We have reported that liver-specific deletion of IGF-I in mice (LI-IGF-I-/-) results in decreased circulating IGF-I and increased GH levels. In the present study, we determined how elimination of hepatic IGF-I modifies the hypothalamic-pituitary GH axis to enhance GH secretion. The pituitary mRNA levels of GH releasing factor (GHRF) receptor and GH secretagogue (GHS) receptor were increased in LI-IGF-I-/- mice, and in line with this, their GH response to ip injections of GHRF and GHS was increased. Expression of mRNA for pituitary somatostatin receptors, hypothalamic GHRF, somatostatin, and neuropeptide Y was not altered in LI-IGF-I-/- mice, whereas hypothalamic IGF-I expression was increased. Changes in hepatic expression of major urinary protein and the PRL receptor in male LI-IGF-I-/- mice indicated an altered GH release pattern most consistent with enhanced GH trough levels. Liver weight was enhanced in LI-IGF-I-/- mice of both genders. In conclusion, loss of liver-derived IGF-I enhances GH release by increasing expression of pituitary GHRF and GHS receptors. The enhanced GH release in turn affects several liver parameters, in line with the existence of a pituitary-liver axis.
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| 18. |
- Walther, Sten, et al.
(author)
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Antibiotic prescription practices, consumption and bacterial resistance in a cross section of Swedish intensive care units
- 2002
-
In: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172. ; 46:9, s. 1075-1081
-
Journal article (peer-reviewed)abstract
- Background: The purpose of this work was to study usage of antibiotics, its possible determinants, and patterns of bacterial resistance in Swedish intensive care units (ICUs). Methods: Prospectively collected data on species and antibiotic resistance of clinical isolates and antibiotic consumption specific to each ICU in 1999 were analyzed together with answers to a questionnaire. Antibiotic usage was measured as defined daily doses per 1000 occupied bed days (DDD1000). Results: Data were obtained for 38 ICUs providing services to a population of approximately 6 million. The median antibiotic consumption was 1257 DDD1000 (range 584–2415) and correlated with the length of stay but not with the illness severity score or the ICU category. Antibiotic consumption was higher in the ICUs lacking bedside devices for hand disinfection (2193 vs. 1214 DDD1000, p=0.05). In the ICUs with a specialist in infectious diseases responsible for antibiotic treatment the consumption pattern was different only for use of glycopeptides (58% lower usage than in other ICUs: 26 vs. 11 DDD1000,P=0.02). Only 21% of the ICUs had a written guideline on the use of antibiotics, 57% received information on antibiotic usage at least every 3 months and 22% received aggregated resistance data annually. Clinically significant antimicrobial resistance was found among Enterbacter spp. to cephalosporins and among Enterococcus spp. to ampicillin. Conclusions: Availability of hand disinfection equipment at each bed and a specialist in infectious diseases responsible for antibiotic treatment were factors that correlated with lower antibiotic consumption in Swedish ICUs, whereas patient-related factors were not associated with antibiotic usage.
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| 19. |
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| 20. |
- Åberg, N David, 1970, et al.
(author)
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Growth hormone increases connexin-43 expression in the cerebral cortex and hypothalamus.
- 2000
-
In: Endocrinology. - 0013-7227. ; 141:10, s. 3879-86
-
Journal article (peer-reviewed)abstract
- Several studies indicate that systemic GH influences various brain functions. Connexin-43 forms gap junctions that mediate intercellular communication and establish the astroglial syncytium. We investigated the effects of peripheral administration of bovine GH (bGH) and recombinant human insulin-like growth factor I (rhIGF-I) on the expression of connexin-43 in the rat brain. Hypophysectomized female Sprague Dawley rats were substituted with cortisol (400 microg/kg x day) and L-T4 (10 microg/kg x day) and treated with either bGH (1 mg/kg x day) or rhIGF-I (0.85 mg/kg x day) for 19 days. The abundance of connexin-43 messenger RNA (mRNA) and protein in the brainstem, cerebral cortex, hippocampus, and hypothalamus was quantified by means of ribonuclease protection assays and Western blots. Treatment with bGH increased the amounts of connexin-43 mRNA and protein in the cerebral cortex and hypothalamus. No changes were found in the brainstem or hippocampus. Infusion of rhIGF-I did not affect connexin-43 mRNA or protein levels in any of the brain regions studied. These results show that administration of bGH increases the abundance of cx43 in specific brain regions, suggesting that GH may influence gap junction formation and thereby intercellular communication in the brain.
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