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1.
Science ; 289(5484): 1519-1524, 2000 Sep 01.
Article in English | MEDLINE | ID: mdl-10968782

ABSTRACT

We use Global Positioning System (GPS) observations and elastic half-space models to estimate the distribution of coseismic and postseismic slip along the Izmit earthquake rupture. Our results indicate that large coseismic slip (reaching 5.7 meters) is confined to the upper 10 kilometers of the crust, correlates with structurally distinct fault segments, and is relatively low near the hypocenter. Continued surface deformation during the first 75 days after the earthquake indicates an aseismic fault slip of as much as 0.43 meters on and below the coseismic rupture. These observations are consistent with a transition from unstable (episodic large earthquakes) to stable (fault creep) sliding at the base of the seismogenic zone.

2.
Science ; 288(5466): 661-5, 2000 Apr 28.
Article in English | MEDLINE | ID: mdl-10784447

ABSTRACT

We calculate the probability of strong shaking in Istanbul, an urban center of 10 million people, from the description of earthquakes on the North Anatolian fault system in the Marmara Sea during the past 500 years and test the resulting catalog against the frequency of damage in Istanbul during the preceding millennium. Departing from current practice, we include the time-dependent effect of stress transferred by the 1999 moment magnitude M = 7.4 Izmit earthquake to faults nearer to Istanbul. We find a 62 +/- 15% probability (one standard deviation) of strong shaking during the next 30 years and 32 +/- 12% during the next decade.

3.
Nature ; 404(6775): 269-73, 2000 Mar 16.
Article in English | MEDLINE | ID: mdl-10749206

ABSTRACT

On 17 August 1999, a destructive magnitude 7.4 earthquake occurred 100 km east of Istanbul, near the city of Izmit, on the North Anatolian fault. This 1,600-km-long plate boundary slips at an average rate of 2-3 cm yr(-1), and historically has been the site of many devastating earthquakes. This century alone it has ruptured over 900 km of its length. Models of earthquake-induced stress change combined with active fault maps had been used to forecast that the epicentral area of the 1999 Izmit event was indeed a likely location for the occurrence of a large earthquake. Here we show that the 1999 event itself significantly modifies the stress distribution resulting from previous fault interactions. Our new stress models take into account all events in the region with magnitudes greater than 6 having occurred since 1700 as well as secular interseismic stress change, constrained by GPS data. These models provide a consistent picture of the long term spatio-temporal behaviour of the North Anatolian fault and indicate that two events of magnitude equal to, or greater than, the Izmit earthquake are likely to occur within the next decades beneath the Marmara Sea, south of Istanbul.

4.
Clin Chem ; 43(8 Pt 1): 1397-407, 1997 Aug.
Article in English | MEDLINE | ID: mdl-9267320

ABSTRACT

We have developed a new assay for cortisone (E) in serum, saliva, and urine involving Celite chromatography followed by RIA with 125I-labeled E and scintillation proximity assay. The chromatography step separates cortisol (F) from E, and in combination with their RIAs, permits assessment of the status of the F-E shuttle. We report the results of basal, postcorticotropin (ACTH), and postdexamethasone E and F concentrations and their circadian fluctuations in the serum, saliva, and urine of healthy volunteers. The serum and urine F/E ratios were increased in patients with ectopic ACTH secretion, whereas in adrenal adenoma and Cushing disease only the urinary ratio was increased. In chronic renal insufficiency this ratio was increased in serum (23.5 +/- 3.9) but diminished in saliva (0.38 +/- 0.11), and in apparent mineralocorticoid excess the ratios were high in serum (44.3 +/- 9.3) and urine (5.35 +/- 0.85) compared with those of healthy subjects (serum 9.8 +/- 3.5, urine 0.52 +/- 0.29, saliva 0.52 +/- 0.29).


Subject(s)
Cortisone/analysis , Hydrocortisone/metabolism , Radioimmunoassay , 11-beta-Hydroxysteroid Dehydrogenases , Adrenal Gland Diseases/metabolism , Adrenocorticotropic Hormone/metabolism , Adult , Chromatography , Circadian Rhythm , Cortisone/blood , Cortisone/immunology , Cortisone/metabolism , Cortisone/urine , Diatomaceous Earth , Female , Humans , Hydrocortisone/immunology , Hydroxysteroid Dehydrogenases/deficiency , Immune Sera/immunology , Kidney Failure, Chronic/metabolism , Male , Middle Aged , Mineralocorticoids/metabolism , Radioimmunoassay/methods , Reference Values , Reproducibility of Results , Saliva/chemistry , Sensitivity and Specificity
5.
Nephrologie ; 18(3): 95-101, 1997.
Article in French | MEDLINE | ID: mdl-9297136

ABSTRACT

Minimal change nephrotic syndrome (MCNS) is the most frequent single cause of nephrotic syndrome occurring both in adults and children. Although it appears to be a self-limiting disorder (10% spontaneous remissions within the fortnight following the initial flare), MCNS displays a high rate of complications during the nephrotic period (10 to 15% cases) and prompts one to treat patients as early as possible. Corticosteroids are currently used as first-line treatment. A 16 weeks full-dose steroid course (1 mg/kg/day) usually induces remission in 75% MCNS in adults. Nevertheless, duration of treatment (9 months) and occurrence of relapses despite a slowly tapering dosage schedule, expose patients to steroids side-effects. Immunosuppressive drugs are recommended in case of steroid resistance and their side-effects are not harmless. Therefore, an alternative to steroids or immunosuppressives would lend a serious helping hand in MCNS management. The present work is dealing with pefloxacin efficacy in 40% MCNS in adults. Thirty-two MCNS adult patients were treated in a national multicenter study. A short-duration pefloxacin course (4 to 6 weeks) allowed partial or complete remission in 13 out of 32 cases. Thus far, this effect was undescribed for this class of drugs. Pefloxacin belongs to antibacterial agents of the fluoroquinolone family and is active against Gram negative Enterobacteria species. Fluoroquinolones also act on eukaryotic cells as lymphocytes and chondrocytes and alter IL2, gamma IFN and integrin expression. Although their precise mode of action is unknown in this kind of immunological disorder, fluoroquinolones might represent an alternative to steroids in some adult form of MCNS. However, predictive criteria for sensitivity to fluoroquinolones are currently not available and further controlled studies would be helpful using fluoroquinolones as first-line treatment in all the MCNS.


Subject(s)
Anti-Infective Agents, Urinary/therapeutic use , Nephrosis, Lipoid/complications , Nephrotic Syndrome/drug therapy , Pefloxacin/therapeutic use , Adolescent , Adult , Aged , Creatinine/blood , Female , Humans , Immunoglobulins/blood , Male , Middle Aged , Nephrosis, Lipoid/metabolism , Nephrotic Syndrome/etiology , Nephrotic Syndrome/metabolism , Pilot Projects , Predictive Value of Tests , Proteinuria/etiology , Remission Induction , Serum Albumin/analysis , Treatment Outcome
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