Topical Tritiated Thymidine for Epidermal Growth Fraction Determination

Direct autoradiographic identification of the epidermal growth fraction (GF) requires the delivery of tritiated thymidine ([3H]dThd) to the skin during the time interval of an entire cell cycle. The GF in normal human epidermis has not been directly measured using this technique because the systemic infusion of radioactive [3H]dThd in benign skin conditions is precluded by ethical considerations. Studies were undertaken to assess the feasibility of measuring the epidermal GF in vivo by the topical delivery of [3H]dThd. The percutaneous penetration of [3dThd in various vehicles was evaluated to select an effective topical delivery system. A vehicle consisting of Azone, isopropanol, and water (2:49:49) was the best of 4 different vehicles tested. The optimal penetration of [3H]dThd, with respect to the concentration of Azone over a range of 0–4%, was achieved at 2%. During the initial 24h following a single topical application of [3H]dThd to hairless mice the labeling increased linearly with time. In vivo studies in hairless mice produced a GF of 95% by both continuous systemic [3H]dThd infusion, and by twice daily topical [3H]dThd. Azone vehicles induced epidermal hyperplasia which was minimized by lowering the Azone concentration and by decreasing the frequency of applications from 24 to 48h. These studies establish the rationale for using topical delivery of [3H]dThd for the in vivo measurement of epidermal GF

Water Conservation Issues Panel Discussion

Proceedings of the 1999 Georgia Water Resources Conference, March 30 and 31, Athens, Georgia.The Georgia Environmental Protection Division is actively committed to facilitating effective water conservation planning throughout the state. Bennett Weinstein was hired on as a water conservation specialist during January of 1999, to act as a resource for Georgia's water purveyors. His responsibilities also include reviewing water conservation plans, the development of a water conservation plan training document, as well as facilitating workshops on water conservation planning to teach water suppliers about the training document. The goal of EPD's focus on water conservation is not merely the submittal of water conservation plans, but to have those water conservation measures implemented. The EPD is currently assisting Georgia's water systems in exploring the benefits and cost savings available through the implementation of sound water conservation practices. Water conservation measures are simply tools that promote efficient use, and like any other tool must be used properly in order to be effective.Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Institute of Ecology, The University of Georgia, Athens, Georgia 30602-2202 with partial funding provided by the U.S. Department of Interior, geological Survey, through the Georgia Water Research Insttitute as authorized by the Water Research Institutes Authorization Act of 1990 (P.L. 101-397). The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of the University of Georgia or the U.S. Geological Survey or the conference sponsors

Intensive Interferon Therapy Does Not Increase Virological Response Rates in African Americans with Chronic Hepatitis C

To determine if an intensive regimen of daily, high-dose interferon would improve the initial response rates to therapy for hepatitis C genotype 1 among African American and Caucasian patients, we conducted a retrospective analysis of a treatment trial conducted between October 1995 and June 1997. Patients were randomized to 24 weeks of therapy with interferon −α- 2b at either 5 MU daily or 3 MU three times a week. On the standard interferon regimen (3 MU three times a week) African Americans and Caucasians had similar initial response rates. However, unlike Caucasians, African Americans did not have an increased initial virological response when treated with an intensive, daily dose regimen. Levels of HCV RNA decreased more slowly during the first 12 weeks of therapy among African Americans. Nelson-Aalen cumulative hazard estimates for the different race and dose combinations revealed that Caucasians who received daily interferon were most likely to have an initial response (logrank, P < 0.001).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44431/1/10620_2004_Article_458700.pd

Optical and Radio Properties of Extragalactic Sources Observed by the FIRST and SDSS Surveys

We discuss the optical and radio properties of 30,000 FIRST sources positionally associated with an SDSS source in 1230 deg$^2$ of sky. The majority (83%) of the FIRST sources identified with an SDSS source brighter than r=21 are optically resolved. We estimate an upper limit of 5% for the fraction of quasars with broad-band optical colors indistinguishable from those of stars. The distribution of quasars in the radio flux -- optical flux plane supports the existence of the "quasar radio-dichotomy"; 8% of all quasars with i<18.5 are radio-loud and this fraction seems independent of redshift and optical luminosity. The radio-loud quasars have a redder median color by 0.08 mag, and a 3 times larger fraction of objects with red colors. FIRST galaxies represent 5% of all SDSS galaxies with r<17.5, and 1% for r<20, and are dominated by red galaxies. Magnitude and redshift limited samples show that radio galaxies have a different optical luminosity distribution than non-radio galaxies selected by the same criteria; when galaxies are further separated by their colors, this result remains valid for both blue and red galaxies. The distributions of radio-to-optical flux ratio are similar for blue and red galaxies in redshift-limited samples; this similarity implies that the difference in their luminosity functions, and resulting selection effects, are the dominant cause for the preponderance of red radio galaxies in flux-limited samples. We confirm that the AGN-to-starburst galaxy number ratio increases with radio flux, and find that radio emission from AGNs is more concentrated than radio emission from starburst galaxies (abridged).Comment: submitted to AJ, color gif figures, PS figures available from [email protected]

Diagnostic accuracy of somatosensory evoked potential monitoring during scoliosis fusion

The goal of this review was to ascertain the diagnostic accuracy of intraoperative somatosensory evoked potential (SSEP) changes to predict perioperative neurological outcome in patients undergoing spinal deformity surgery to correct adolescent idiopathic scoliosis (AIS). The authors searched PubMed/MEDLINE and World Science databases to retrieve reports and/or experiments from January 1950 through January 2014 for studies on SSEP use during AIS surgery. All motor and sensory deficits were noted in the neurological examination administered after the procedure which was used to determine the effectiveness of SSEP as an intraoperative monitoring technique. Fifteen studies identified a total of 4763 procedures on idiopathic patients. The observed incidence of neurological deficits was 1.11% (53/4763) of the sample population. Of the patients with new postoperative neurological deficits 75.5% (40/53) showed significant SSEP changes, and 24.5% (13/53) did not show significant change. Pooled analysis using the bivariate model showed SSEP change with pooled sensitivity (average 84%, 95% confidence interval 59-95%) and specificity (average 98%, 95% confidence interval 97-99%). The diagnostic odds ratio of a patient who had a new neurological deficit with SSEP changes was a diagnostic odds ratio of 340 (95% confidence interval 125-926). Overall, detection of SSEP changes had excellent discriminant ability with an area under the curve of 0.99. Our meta-analysis covering 4763 operations on idiopathic patients showed that it is a highly sensitive and specific test and that iatrogenic spinal cord injury resulting in new neurological deficits was 340 times more likely to have changes in SSEP compared to those without any new deficits

Characterization of systematic error in Advanced LIGO calibration

The raw outputs of the detectors within the Advanced Laser Interferometer Gravitational-Wave Observatory need to be calibrated in order to produce the estimate of the dimensionless strain used for astrophysical analyses. The two detectors have been upgraded since the second observing run and finished the year-long third observing run. Understanding, accounting, and/or compensating for the complex-valued response of each part of the upgraded detectors improves the overall accuracy of the estimated detector response to gravitational waves. We describe improved understanding and methods used to quantify the response of each detector, with a dedicated effort to define all places where systematic error plays a role. We use the detectors as they stand in the first half (six months) of the third observing run to demonstrate how each identified systematic error impacts the estimated strain and constrain the statistical uncertainty therein. For this time period, we estimate the upper limit on systematic error and associated uncertainty to be $< 7\%$ in magnitude and $< 4$ deg in phase ($68\%$ confidence interval) in the most sensitive frequency band 20-2000 Hz. The systematic error alone is estimated at levels of $< 2\%$ in magnitude and $< 2$ deg in phase

Impact of Obesity and Knee Osteoarthritis on Morbidity and Mortality in Older Americans

Obesity and knee osteoarthritis are among the most frequent chronic conditions affecting Americans aged 50 to 84 years

Hundreds of variants clustered in genomic loci and biological pathways affect human height

Most common human traits and diseases have a polygenic pattern of inheritance: DNA sequence variants at many genetic loci influence the phenotype. Genome-wide association (GWA) studies have identified more than 600 variants associated with human traits, but these typically explain small fractions of phenotypic variation, raising questions about the use of further studies. Here, using 183,727 individuals, we show that hundreds of genetic variants, in at least 180 loci, influence adult height, a highly heritable and classic polygenic trait. The large number of loci reveals patterns with important implications for genetic studies of common human diseases and traits. First, the 180 loci are not random, but instead are enriched for genes that are connected in biological pathways (P = 0.016) and that underlie skeletal growth defects (P < 0.001). Second, the likely causal gene is often located near the most strongly associated variant: in 13 of 21 loci containing a known skeletal growth gene, that gene was closest to the associated variant. Third, at least 19 loci have multiple independently associated variants, suggesting that allelic heterogeneity is a frequent feature of polygenic traits, that comprehensive explorations of already-discovered loci should discover additional variants and that an appreciable fraction of associated loci may have been identified. Fourth, associated variants are enriched for likely functional effects on genes, being over-represented among variants that alter amino-acid structure of proteins and expression levels of nearby genes. Our data explain approximately 10% of the phenotypic variation in height, and we estimate that unidentified common variants of similar effect sizes would increase this figure to approximately 16% of phenotypic variation (approximately 20% of heritable variation). Although additional approaches are needed to dissect the genetic architecture of polygenic human traits fully, our findings indicate that GWA studies can identify large numbers of loci that implicate biologically relevant genes and pathways.