State-level adjusted ESRD incident rates: use of observed vs model-predicted category-specific rates

Because of differences in case-mix across states, state-level case-mix-adjusted end-stage renal disease (ESRD) incident rates are reported in each United States Renal Data System Annual Data Report to make the across-state comparisons valid. The adjusted rates were estimated by the direct adjustment method, a widely used method for adjusted event rate calculation, based on observed category-specific ESRD incident rates in each state (called the observation-based method). However, when some adjusting categories in a state are small, the adjusted rate and the standard error for this state as estimated by this method may be inaccurate. This report proposes a model-based method that can overcome the disadvantages of the observation-based method and can be extended to continuous adjusting variables. National ESRD incident data and national population data from 1990 to 1999 were used. State-level adjusted ESRD incident rates were estimated by both the observation- and the model-based methods. For the model-based method, a Poisson regression model was used to estimate category-specific ESRD incident rates. For large-population states, both observation- and model-based methods produced similar estimates for adjusted ESRD incident rates. For small-population states, however, the observation-based method produced year-to-year estimates of adjusted ESRD incident rates that varied considerably and also had very large standard errors. In contrast, the model-based method produced stable estimates. The model-based method can overcome the disadvantages of the observation-based method for estimating state-level adjusted ESRD incident rates, especially for small states.

Intervalley gap anomaly of two-dimensional electrons in silicon

We report here a systematic study of the energy gaps at the odd-integer quantum Hall states nu = 3 and 5 under tilted magnetic (B) fields in a high quality Si two-dimensional electron system. Out of the coincidence region, the valley splitting is independent of the in-plane fields. However, the nu = 3 valley gap differs by about a factor of 3 (Deltav approximately 0.4 vs 1.2 K) on different sides of the coincidence. More surprisingly, instead of reducing to zero, the energy gaps at nu = 3 and 5 rise rapidly when approaching the coincidence angles. We believe that such an anomaly is related to strong couplings of the nearly degenerate Landau levels.

cisRED: a database system for genome-scale computational discovery of regulatory elements

We describe cisRED, a database for conserved regulatory elements that are identified and ranked by a genome-scale computational system (www.cisred.org). The database and high-throughput predictive pipeline are designed to address diverse target genomes in the context of rapidly evolving data resources and tools. Motifs are predicted in promoter regions using multiple discovery methods applied to sequence sets that include corresponding sequence regions from vertebrates. We estimate motif significance by applying discovery and post-processing methods to randomized sequence sets that are adaptively derived from target sequence sets, retain motifs with p-values below a threshold and identify groups of similar motifs and co-occurring motif patterns. The database offers information on atomic motifs, motif groups and patterns. It is web-accessible, and can be queried directly, downloaded or installed locally.

Circadian and extracircadian exploration during daytime hours of circulating corticosterone and other endocrine chronomes

During 7 consecutive days, blood and several tissues were collected during daytime working hours only, three times per day at 4-h intervals from inbred Wistar rats, which had been previously standardized for 1 month in two rooms on a regimen of 12 h of light (L) alternating with 12 h of darkness (LD12:12). In one room, lights were on from 09:00 to 21:00 and in the other room, lights were on from 21:00 to 09:00 (DL12:12; reversed lighting regimen). This setup provides a convenient design to study circadian and extracircadian variations over long (e.g., 7-day) spans. Prior checking of certain circadian rhythms in animals reared in the room on reversed lighting (DL) as compared with animals in the usual (LD) regimen provided evidence that the 180 degrees phase-shift had occurred. These measurements were limited to the circadian (and not extended to infradian) variation. As marker rhythm, the core temperature of a subsample of rats was measured every 4 h around the clock (by night as well as by day) before the start of the 7-day sampling. An antiphase of the circadian rhythm in core temperature was thus demonstrated between rats in the LD vs. DL rooms. A sex difference in core temperature was also found in each room. A reversed rhythm in animals kept in DL and an antiphase between rats kept in DL vs. LD was again shown for the circulating corticosterone rhythm documented in subsamples of 8 animals of each sex sampled around the clock during the first approximately 1.5 day of the 7-day sampling. The findings were in keeping with the proposition that sampling rats at three timepoints 4 h apart during daytime from two rooms on opposite lighting regimens allows the assessment of circadian changes, the daytime samples from animals kept on the reversed lighting regimen accounting for the samples that would have to be obtained by night from animals kept in the room with the usual lighting regimen. During the 7-day-long follow-up, circadian and extracircadian spectral components were mapped for serum corticosterone, taking into account the large day-to-day variability. A third check on the synchronization of the animals to their respective lighting regimen was a comparison (and a good agreement) between studies carried out earlier on the same variables and the circadian results obtained on core temperature and serum corticosterone in this study as a whole. The present study happened to start on the day of the second extremum of a moderate double magnetic storm. The study of any associations of corticosterone with the storm is beyond our scope herein, as are the results on circulating prolactin, characterized by a greater variability and a larger sex difference than corticosterone. Sex differences and extracircadian aspects of prolactin and endothelin determined in the same samples are reported elsewhere, as are results on melatonin. Prior studies on melatonin were confirmed insofar as a circadian profile is concerned by sampling on two antiphasic lighting regimens, as also reported elsewhere. Accordingly, a circadian map for the rat will eventually be extended by the result of this study and aligned with other maps with the qualification of the unassessed contribution in this study of a magnetic storm.

Chronomics, neuroendocrine feedsidewards and the recording and consulting of nowcasts--forecasts of geomagnetics

A multi-center four-hourly sampling of many tissues for 7 days (00:00 on April 5-20:00 to April 11, 2004), on rats standardized for 1 month in two rooms on antiphasic lighting regimens happened to start on the day after the second extremum of a moderate double magnetic storm gauged by the planetary geomagnetic Kp index (which at each extremum reached 6.3 international [arbitrary] units) and by an equatorial index Dst falling to -112 and -81 nT, respectively, the latter on the first day of the sampling. Neuroendocrine chronomes (specifically circadian time structures) differed during magnetically affected and quiet days. The circadian melatonin rhythm had a lower MESOR and lower circadian amplitude and tended to advance in acrophase, while the MESOR and amplitude of the hypothalamic circadian melatonin rhythm were higher during the days with the storm. The circadian parameters of circulating corticosterone were more labile during the days including the storm than during the last three quiet days. Feedsidewards within the pineal-hypothalamic-adrenocortical network constitute a mechanism underlying physiological and probably also pathological associations of the brain and heart with magnetic storms. Investigators in many fields can gain from at least recording calendar dates in any publication so that freely available information on geomagnetic, solar and other physical environmental activity can be looked up. In planning studies and before starting, one may gain from consulting forecasts and the highly reliable nowcasts, respectively.

Chronomics reveal and quantify circadian rhythmic melatonin in duodenum of rats

A circadian rhythm is documented in duodenal melatonin in rats, peaking 16.8 hours after light onset. This component is more readily detected after log10-transformation of the data. It differs between male and female rats, females having a larger circadian amplitude and an earlier acrophase. The circadian rhythm in duodenal melatonin is also found to lead that of pineal melatonin. The results are qualified by the presence at the start of mapping of the second extremum of a double magnetic storm.

Chronomics: circadian lead of extrapineal vs. pineal melatonin rhythms with an infradian hypothalamic exploration

A circadian rhythm is documented for plasma, pineal, and hypothalamic melatonin of male and female rats kept on staggered lighting regimens. Log[_10]-transformation of the data usually normalizes, when need be, the distribution of residuals from the 24-hour cosine curve fits. A tentative circadian acrophase chart is presented that shows a lead in circadian acrophase of duodenal over pineal melatonin. The use of antiphasic lighting regimens facilitates circadian studies that can be carried out for several days, thereby allowing the assessment of infradian components such as a circasemiseptan variation in hypothalamic melatonin documented herein. The results are qualified by the presence of a second extremum of a double magnetic storm at the start of mapping.

Impact of school-based health centers on children with asthma

PURPOSE

To quantitatively assess the impact of school-based health centers (SBHCs) on hospitalization and emergency department (ED) visits for children with asthma.

METHODS

The study was conducted at four SBHC intervention school districts and two comparable non-SBHC school districts in Greater Cincinnati, Ohio. A longitudinal quasi-experimental time-series repeated measures design was used with a study period from 1997 to 2003. Children with asthma with at least 2 years of continuous enrollment who had medical claims for asthma diagnosis and antiasthmatic medications were selected. The primary data sources were student enrollment data from the schools and the Ohio Medicaid claims database. Generalized estimating equation (GEE) analysis and analysis of covariance were used to assess the intervention effect before and after the SBHC program.

RESULTS

Asthma was one of the major diseases for SBHC encounters. Major prescription drugs that SBHC staff managed for children with asthma included albuterol, montelukast, fluticasone, budesonide, and triamcinolone. Of 273 children (196 in SBHC schools and 77 in non-SBHC schools), 42% were female, 41.7% African-Americans, and the average age was 8.2 years. After the opening of the SBHC, relative risks of hospitalization and ED visits in the SBHC group decreased 2.4-fold and 33.5%, respectively. The cost of hospitalization per child decreased significantly over time for children in SBHC schools (F = 4.115, p = .044). After SBHCs opened, cost of hospitalization decreased for African-American children (F = 5.198, p = .023). Costs of ED visits for children in SBHC schools were significantly lower than children in non-SBHC schools (F = 19.8, p < .0001).

CONCLUSIONS

The risk of hospitalization and ED visits for children with asthma decreased significantly with SBHC programs. The potential cost-savings for hospitalization was estimated as 970 dollars per child.

Chronomics affirm extending scope of lead in phase of duodenal vs. pineal circadian melatonin rhythms

In Göttingen, Germany, circadian variations in melatonin had been determined time-macroscopically in pineal glands, blood plasma and duodenum of chicken and rats. When these data were meta-analyzed, they agreed with the results from an independent survey on tissues from rats collected in a laboratory in Pécs, Hungary. In the latter study, tissues were analyzed chemically in Bratislava, Slovakia, and numerically in Minneapolis, MN, USA, all by single- and multiple-component cosinor and parameter tests. In rats and chickens, these inferential statistical procedures clearly demonstrated a lead in phase of the 24-h cosine curves best fitting all of the duodenal vs. those best fitting all of the pineal melatonin values in each species in 2 geographic (geomagnetic) locations. The 24-h cosine curve of circulating melatonin was found to be in an intermediate phase position. Mechanisms of the phase differences and the contribution of gastrointestinal melatonin to circulating hormone concentrations are discussed.

Quantization of the diagonal resistance: density gradients and the empirical resistance rule in a 2D system

We have observed quantization of the diagonal resistance, R(xx), at the edges of several quantum Hall states. Each quantized R(xx) value is close to the difference between the two adjacent Hall plateaus in the off-diagonal resistance, R(xy). Peaks in R(xx) occur at different positions in positive and negative magnetic fields. Practically all R(xx) features can be explained quantitatively by a 1%/cm electron density gradient. Therefore, R(xx) is determined by R(xy) and unrelated to the diagonal resistivity rho(xx). Our findings throw an unexpected light on the empirical resistivity rule for 2D systems.

Reversible H-induced switching of the magnetic easy axis in Ni/Cu(001) thin films

A reversible switching of the easy axis of magnetization for Ni on Cu(001) from in plane to out of plane is found by changing the partial pressure of hydrogen in the gas phase around the sample, allowing even for oscillations of the magnetization direction. A quantitative low-energy electron diffraction study of the diffracted intensity versus electron energy [I(E)] shows that the hydrogen-induced spin reorientation transition is accompanied by changes of the tetragonal distortion of the topmost Ni layer upon hydrogen adsorption. Surprisingly, the orientation switch to perpendicular to the surface comes with a relaxation, i.e., reduction of the film's tetragonal distortion rather than its amplification.

Electron correlation in the second Landau level: a competition between many nearly degenerate quantum phases

At a very low-temperature of 9 mK, electrons in the second Landau level of an extremely high-mobility two-dimensional electron system exhibit a very complex electronic behavior. With a varying filling factor, quantum liquids of different origins compete with several insulating phases leading to an irregular pattern in the transport parameters. We observe a fully developed nu=2+2/5 state separated from the even-denominator nu=2+1/2 state by an insulating phase and a nu=2+2/7 and nu=2+1/5 state surrounded by such phases. A developing plateau at nu=2+3/8 points to the existence of other even-denominator states.

Two-flux composite fermion series of the fractional quantum Hall states in strained Si

Magnetotransport properties are investigated in a high-mobility two-dimensional electron system in the strained Si quantum well of a (100) Si(0.75)Ge(0.25)/Si/Si(0.75)Ge0.25 heterostructure, at temperatures down to 30 mK and in magnetic fields up to 45 T. We observe around nu=1/2 the two-flux composite fermion (CF) series of the fractional quantum Hall effect (FQHE) at nu=2/3, 3/5, 4/7, and at nu=4/9, 2/5, 1/3. Among these FQHE states, the nu=1/3, 4/7, and 4/9 states are seen for the first time in the Si/SiGe system. Interestingly, of the CF series, the 3/5 state is weaker than the nearby 4/7 state and the 3/7 state is conspicuously missing, resembling the observation in the IQHE regime that the nu=3 is weaker than the nearby nu=4 state. Our results can be quantitatively understood in the picture of CF's with the valley degree of freedom.

Inhibition of papilloma progression by antisense oligonucleotides targeted to HPV11 E6/E7 RNA

Human papillomaviruses (HPVs) are recognized as important human pathogens, causing a spectrum of hyperproliferative lesions from benign warts to cervical dysplasias/carcinomas. HPV-associated lesions require continued production of the oncogenic E6/E7 proteins, which are encoded by either bicistronic or overlapping mRNAs. Here we targeted the E6/E7 mRNA of HPV11, a type implicated in causation of genital warts, using molecular reagents. Accessible sites in the HPV11(E6/E7) RNA were identified using library selection protocols, and nucleic acids (DNAzymes, antisense oligonucleotides) targeted to these sites were constructed, and tested in cell culture and on human foreskin grafts. While DNAzymes were at least equally effective in cell culture, antisense oligonucleotides targeted to the region surrounding one of the library-selected sites (ASO(407)) proved most effective in blocking progression of HPV11-induced papillomas in human foreskin grafts on immunodeficient mice. In total, 11 papillomas were treated with ASO(407). Of these, four of seven small papillomas treated with ASO(407) showed loss of detectable virus by in situ hybridization (ISH), and in all four of these, papillomas were no longer evident grossly or histologically after treatment. When larger papillomas were treated, one of four showed loss of virus by ISH, associated with a minor decrease in papilloma size. Considering all 11 papillomas treated with ASO(407), loss of viral staining by ISH was significantly different from that observed in controls (P<0.016), as was true for the seven small treated papillomas (P<0.012). DNAzymes targeted to the same site (or other library selected sites) did not produce statistically significant differences in ISH staining (P<0.15). Our results with ASO(407) appear to represent the first specific molecular therapy against a bona fide HPV infection, and provide a rational proof-of-principle strategy for development of molecular therapeutics targeting other HPV-associated lesions.

Synergistic anti-tumor effect of ultrasound and hematoporphyrin on sarcoma180 cells with special reference to the changes of morphology and cytochrome oxidase activity of tumor cells

This study is aimed at evaluating the inhibitory effects of the association of hematoporphyrin and ultrasound at variable intensities with a fixed frequency of 1.1MHz in tumor nodules. Specifically, the effects were studied both in solid and ascitic S180 tumors transplanted in mice by clinical, cytochemical and ultrastructural evaluation. The results indicated that the use of hematoporphyrin alone had no significant effect on destroying tumor cells. The ultrasound alone had little effect. Interestingly, the inhibition was much more effective when hematoporphyrin was combined with ultrasound. The inhibition was 3 times better than ultrasound alone and 8 times better than hematoporphyrin used alone. Our results also indicated that the changes on cell structure and cytochrome oxidation activity are important factors that could inhibit tumor cell growth and induce cell death. Apoptosis of tumor cells could be induced by hematoporphyrin. Our study investigated the killing mechanism on S180 tumor cells by using hematoporphyrin and low frequency ultrasound at cell, tissue and individual level.

Feeding peptides interact in several ways with the blood-brain barrier

The blood-brain barrier (BBB) plays a crucial role in the regulation of body weight and feeding by peptides. This review summarizes the components of the BBB as well as the circumventricular organs (CVOs), the methods used for quantification of the passage of feeding peptides across the BBB, and the various ways by which these peptides can interact with the BBB.

The effects of diabetes on the risks of major cardiovascular diseases and death in the Asia-Pacific region

OBJECTIVE

To provide reliable age- and region-specific estimates of the associations between diabetes and major cardiovascular diseases and death in populations from the Asia-Pacific region.

RESEARCH DESIGN AND METHODS

Twenty-four cohort studies from Asia, Australia, and New Zealand (median follow-up, 5.4 years) provided individual participant data from 161,214 people (58% from Asia) of whom 4,873 had a history of diabetes at baseline. The associations of diabetes with the risks of coronary heart disease, stroke, and cause-specific mortality during follow-up were estimated using time-dependent Cox models, stratified by study cohort and sex and adjusted for age at risk.

RESULTS

In all, 9,277 deaths occurred (3,635 from cardiovascular disease). The hazard ratio (95% CI) associated with diabetes was 1.97 (1.72-2.25) for fatal cardiovascular disease; there were similar hazard ratios for fatal coronary heart disease, fatal stroke, and composites of fatal and nonfatal outcomes. For all cardiovascular outcomes, hazard ratios were similar in Asian and non-Asian populations and in men and women, but were greater in younger than older individuals. For noncardiovascular death, the hazard ratio was 1.56 (1.38-1.77), with separately significant increases in the risks of death from renal disease, cancer, respiratory infections, and other infective causes. The hazard ratio for all-causes mortality was 1.68 (1.55-1.84), with similar ratios in Asian and non-Asian populations, but with significantly higher ratios in younger than older individuals.

CONCLUSIONS

The relative effect of diabetes on the risks of cardiovascular disease and death in Asian populations is much the same as that in the largely Caucasian populations of Australia and New Zealand. Hazard ratios were severalfold greater in younger people than older people. The rapidly growing prevalence of diabetes in Asia heralds a large increase in the incidence of diabetes-related death in the coming decades.

Fractional quantum Hall effect of composite fermions

In a GaAs/AlGaAs quantum well of density 1 x 10(11) cm(-2) we observed a fractional quantum Hall effect (FQHE) at nu = 4/11 and 5/13, and weaker states at nu = 6/17, 4/13, 5/17, and 7/11. These sequences of fractions do not fit into the standard series of integral quantum Hall effects of composite fermions (CF) at nu = p/(2mp +/- 1). They rather can be regarded as the FQHE of CFs attesting to residual interactions between these composite particles. In tilted magnetic fields the nu = 4/11 state remains unchanged, strongly suggesting it to be spin polarized. The weak nu = 7/11 state vanishes quickly with tilt.

Construction and identification of a single stranded cDNA clone containing full-length genome of hepatitis G virus

AIM

To construct a single cDNA clone with full-length genome of hepatitis G virus (HGV) could be transcribed and expressed in vitro.

METHODS

The 5 initial HGV cDNA fragments of Iw5, Iwq2, Iwh6, Iw3 and Iw3 used in this study were amplified from serum of a Japanese non A-E hepatitis patient. These fragments overlapped and covered the entire genome from 5'-end to 3'-end of HGV cDNA. Overlap extension PCR and ligation methods were used with 12 primers for the construction of a full-length genomic HGV cDNA clone from the subgenomic fragments.

RESULTS

A single HGV cDNA clone (pHGVqz) was successfully constructed, physical mapping of the generated pHGVqz found identical to what we expected, and the sequence was deposited with the GenBank under the Accession number AF081782. The analysis of the full-length sequence, which was able to be in vitro transcribed and expressed, showed that this single clone contained 9373 nucleotides (encoding 2873 amino acids), and shared high homologies with other compared HGV isolates.

CONCLUSION

A full-length genomic HGV cDNA clone is generated for the first of the kind in this study, it could be expressed and transcripted. This single cDNA clone is expected to be of importance in the investigation on replication and pathogenicity of HGV.

Transition from an electron solid to the sequence of fractional quantum Hall states at very low Landau level filling factor

At low Landau level filling of a two-dimensional electron system, typically associated with the formation of an electron crystal, we observe local minima in Rxx at filling factors nu = 2/11, 3/17, 3/19, 2/13, 1/7, 2/15, 2/17, and 1/9. Each of these developing fractional quantum Hall (FQHE) states appears only above a filling-factor-specific temperature. This can be interpreted as the melting of an electron crystal and subsequent FQHE liquid formation. The observed sequence of FQHE states follows the series of composite fermion states emanating from nu = 1/6 and nu = 1/8.