bluuebunny/crossref_metadata_2025 huggingface dataset:
Sustained low‐efficiency dialysis with filtration (SLEDD‐f) in the management of acute sodium valproate intoxication
Authors: KHAN Emon , HUGGAN Paul , CELI Leo , MACGINLEY Robert , SCHOLLUM John , WALKER Robert
Published: April 2008

Hemodialysis is only infrequently used in drug overdosage situations. The efficacy of hemodialysis to remove the drug depends upon the pharmacokinetics and pharmacodynamics of the drug. At normal therapeutic concentrations, valproic acid is predominantly protein bound and therefore removal by hemodialysis is limited. In an overdose situation, protein binding is rapidly saturated and therefore the substantially larger quantities of the free drug can rapidly cause toxicity. Slow low‐efficient daily diafiltration (SLEDD) has not previously been utilized in a drug overdose situation. We report the effective use of SLEDD to remove high toxic concentrations of valproic acid in an overdose situation. Slow low‐efficient daily diafiltration also prevented the rebound phenomenon that can occur as the excess drug is released from its protein‐bound stores. Hybrid dialysis therapies deserve further evaluation in the management of other poisonings where extra‐corporeal therapy is indicated.
Gustatory sweating recurring on peritoneal dialysis but resolving during periods of hemodialysis
Authors: DISKIN Charles J. , STOKES Thomas J. , DANSBY Linda M. , RADCLIFF Lautrec , CARTER Thomas B.
Published: April 2008

Gustatory sweating is a rare disorder characterized by profuse sweating on the forehead, face, scalp, and neck occurring soon after ingesting food, which has been reported in diabetic patients. The mechanism is thought to be triggered by taste buds and not gastric stimulation. We report a case where gustatory sweating repeatedly developed on peritoneal dialysis that resolved on periods of hemodialysis. A 32‐year‐old woman with diabetic end‐stage renal disease developed gustatory sweating shortly after beginning continuous ambulatory peritoneal dialysis despite excellent clearances. After 5 months, she changed to hemodialysis for 2 months and noticed complete resolution of her gustatory sweating; however, after her return to peritoneal dialysis 2 months later, her gustatory sweating recurred. While on peritoneal dialysis, she was treated with clonidine, which resulted in improvement but not resolution of her symptoms as had occurred on hemodialysis. Another period on hemodialysis resulted in the resolution of her symptoms that returned again after restarting peritoneal dialysis. Clonidine provided incomplete relief while topical glycopyrrolate was effective and without complications. We report recurrent gustatory sweating on peritoneal dialysis that resolved with hemodialysis. We have no data to suggest that intra‐abdominal stimulation played a role, but rather that despite excellent clearances neuropathy may have played a role. Treatment with topical glycopyrrolate may be safe and effective given every third day if clonidine is ineffective.
Prediction of hemodialysis sorbent cartridge urea nitrogen capacity and sodium release from in vitro tests
Authors: ROSENBAUM Benjamin P. , ASH Stephen R. , WONG Raymond J. , THOMPSON R. Preston , CARR David J.
Published: April 2008

In sorbent‐based hemodialysis, factors limiting a treatment session are urea conversion capacity and sodium release from the cartridge. In vitro experiments were performed to model typical treatment scenarios using various dialyzers and 4 types of SORB™ sorbent cartridges. The experiments were continued to the point of column saturation with ammonium. The urea nitrogen removed and amount of sodium released in each trial were analyzed in a multi‐variable regression against several variables: amount of zirconium phosphate (ZrP), dialysate flow rate (DFR), simulated blood flow rate (BFR), simulated patient whole‐body fluid volume (V), initial simulated patient urea concentration (BUNi), dialyzer area permeability (KoA) product, initial dialysate sodium and bicarbonate (HCO3i) concentrations, initial simulated patient sodium (Nai), pH of ZrP, creatinine, breakthrough time, and average urea nitrogen concentration in dialysate. The urea nitrogen capacity (UNC) of various new SORB™ columns is positively related to ZrP, BFR, V, BUNi, and ZrP pH and negatively to DFR with an R2adjusted=0.990. Two models are described for sodium release. The first model is related positively to DFR and V and negatively to ZrP, KoA product, and dialysate HCO3i with an R2adjusted=0.584. The second model incorporates knowledge of initial simulated patient sodium (negative relationship) and urea levels (negative relationship) in addition to the parameters in the first model with an R2adjusted=0.786. These mathematical models should allow for prediction of patient sodium profiles and the time of column urea saturation based on simple inputs relating to patient chemistries and the dialysis treatment.
Statins are associated with a reduced risk of bone fracture in hemodialysis (HD) patients
Authors: NICHOLS Robert , HOPMAN Wilma M. , MORTON Alexander R. , HARMAN Gavin J. , HOLDEN Rachel M.
Published: April 2008

The Dialysis Outcomes and Practice Patterns Study reported a statistically non‐significant protective effect of HMG‐co reductase inhibitors (statins) on bone fracture risk in hemodialysis (HD) patients. We sought to determine whether statin exposure was associated with reduced risk of bone fracture in our HD population. This was a retrospective cohort study of 174 prevalent HD patients. Fracture data are abstracted from the medical record. Subjects were considered to be on a statin if they were exposed at any time since the date of dialysis initiation. The subjects were 174 HD patients (68.4% male) with a median age of 69.1 and age range from 25.2 to 96.3 years. The median age at initiation of HD was 62.5, ranging from 15.2 to 90.5 years. The mean (SD) dialysis vintage was 7.3 (4.5) years. Seventy‐seven subjects (44.3%) had statin exposure. There were a total of 54 first bone fractures. There was a positive correlation between bone fracture and dialysis vintage (p=0.023) and a negative association between bone fracture and statin exposure (p=0.044). Those with statin exposure had a higher prevalence of CAD (p=0.030) compared with those not exposed. Logistic regression analysis (stepwise, α=0.05) was performed with dependent variable bone fracture and independent variables age at HD initiation (forced), dialysis vintage, gender (forced), prednisone use (forced), and statin exposure. The significant predictors of bone fracture (R2=0.14, p=0.004) were age at HD initiation (p=0.016), dialysis vintage (p=0.007), and absence of statin exposure (p=0.019). Statin exposure appears to be associated with a reduced frequency of bone fracture in HD patients. Future studies evaluating the potential anabolic effect of statins on bone are required.
Ultra‐High‐Temperature Ceramic Coatings for Oxidation Protection of Carbon–Carbon Composites
Authors: Corral Erica L. , Loehman Ronald E.
Published: April 2008

Carbon–carbon (C–C) composites are attractive materials for hypersonic flight vehicles but they oxidize in air at temperatures >500°C and need thermal protection systems to survive aerothermal heating. We investigated using multilayers of high‐temperature ceramics such as ZrB2 and SiC to protect C–C against oxidation. Our approach combines pretreatment and processing steps to create continuous and adherent high‐temperature ceramic coatings from infiltrated preceramic polymers. We tested our protective coatings at temperatures above 2600°C at the National Solar Thermal Testing Facility using controlled cold‐wall heat flux profiles reaching a maximum of 680 W/cm2.
Theoretical Investigation for the Active‐to‐Passive Transition in the Oxidation of Silicon Carbide
Authors: Wang Junjie , Zhang Litong , Zeng Qingfeng , Vignoles Gérard L. , Guette Alain
Published: April 2008

The oxidation of silicon carbide at high temperatures from 673.15 to 2173.15 K is investigated by using thermodynamic equilibrium calculations and a mass transfer model. The dominant reaction of the active‐to‐passive transition and five other dominant reactions, which are in six different temperature regions, have been determined according to the main equilibrium products. Then, a modified Wagner's model has been developed to determine the active‐to‐passive transition boundary by combining mass transport and thermodynamic calculations. The present theoretical calculations satisfactorily explained the reported experimental and theoretical data. The influence of flow rate on the active‐to‐passive transition boundary has been explained using our model. The rate controlling mechanism of the oxidation at the active‐to‐passive transition point is proposed.
Raman Spectroscopy of Ferroelectric Thin Films and Superlattices
Authors: Tenne Dmitri A. , Xi Xiaoxing
Published: April 2008

Recent results of Raman spectroscopy studies of lattice dynamics and phase transitions in ferroelectric thin films and superlattices are reviewed. Raman studies of SrTiO3, BaTiO3, and BaxSr1−xTiO3 thin films in comparison with corresponding single crystals are presented; essential differences in the lattice dynamics behavior of thin films and single crystals are discussed. Application of ultraviolet Raman spectroscopy for studies of nanoscale ferroelectric heterostructures, such as BaTiO3/SrTiO3 superlattices, is demonstrated.
Sol–Gel Route to Nanocrystalline Lithium Metasilicate Particles
Authors: Zhang Bo , Nieuwoudt Michel , Easteal Allan J.
Published: April 2008

Crystalline lithium metasilicate (Li2SiO3) nanoparticles have been synthesized using a sol–gel process with tetraethylorthosilicate and lithium ethoxide as precursors. The particle size examined by using transmission electron microscopy and BET‐specific surface area techniques is in the range 5–50 nm, depending on the temperature at which the material is calcined. The crystalline Li2SiO3 forms at ambient temperature (∼40°C), and it remains in this phase after calcination at temperatures up to 850°C. The BET‐specific surface area is ∼110 m2/g for material calcined at temperatures below 500°C, decreasing to ∼29 and ∼0.7 m2/g following calcination at 700° and 850°C, respectively. Solid‐state 29Si NMR spectroscopy shows the presence of only Q2 structural units in the material. The lithium metasilicate is further characterized using differential scanning calorimetry and thermogravimetric analysis, and Fourier transform infrared spectroscopy.
Genotypic profiles and virulence attributes of Candida albicans isolates from patients with oral lichen planus
Authors: ZENG XIN , XIONG CHUNRONG , WANG ZHI , JIANG LU , HOU XIAOHUI , SHEN JUN , ZHOU MIN , CHEN QIANMING
Published: April 2008

Candida albicans carriage has been found to be increased in patients with oral lichen planus. In the present work we have investigated the genotypic profiles of 112 C. albicans strains isolated from patients with erosive or nonerosive OLP, and from healthy controls. The virulence attributes of the isolated strains were compared to elucidate the pathogenetic mechanisms through which C. albicans may cause OLP. We have characterized the genotypic profiles of these isolated strains using a randomly amplified polymorphic DNA assay. In addition, we used assays to measure adhesion to buccal epithelial cells and phospholipase activity to evaluate the virulence attributes of these isolates. Our RAPD analyses revealed four different genotypes, named type A to D, among all isolates, and identified statistically significant associations with disease conditions. Specifically, type A (58.1%) and C (29.0%) were primarily found in erosive OLP, while type A (33.3%) and D (58.3%) were identified in nonerosive OLP. However, the healthy group seemed to have type B (38.5%) and D (61.5%). Using adhesion to BEC assay, we demonstrated that the isolates with genotype A had the strongest adherence among the four genotypes (P=0.000<0.05). The phospholipase activity of the isolates with genotype A and C was higher than for those with genotype B and D (P=0.000<0.05). In conclusion, some C. albicans isolates with special genotypic profiles and virulence attributes may contribute to the pathogenesis of OLP.
The lower genital tract microbiota in relation to cytokine‐, SLPI‐ and endotoxin levels: application of checkerboard DNA‐DNA hybridization (CDH)
Authors: NIKOLAITCHOUK NATALIA , ANDERSCH BJÖRN , FALSEN ENEVOLD , STRÖMBECK LOUISE , MATTSBY‐BALTZER INGER
Published: April 2008

In the present study the lower genital tract microbiota in asymptomatic fertile women (n=34) was identified and quantified by culturing vaginal secretions. Also, vaginal and cervical samples were analyzed by a semiquantitative checkerboard DNA‐DNA hybridization technique (CDH) based on genomic probes prepared from 13 bacterial species (Bacteroides ureolyticus, Escherichia coli, Fusobacterium nucleatum, Gardnerella vaginalis, Mobiluncus curtisii ss curtisii, Prevotella bivia, Prevotella disiens, Prevotella melaninogenica, Atopobium vaginae, Lactobacillus iners, Staphylococcus aureus ss aureus, Streptococcus anginosus, and Streptococcus agalactiae). The bacterial species found by either culture or CDH were correlated with proinflammatory cytokines (IL‐1α, IL‐1β, IL‐6, IL‐8), secretory leukocyte protease inhibitor (SLPI), and endotoxin in the cervicovaginal samples. Grading the women into healthy, intermediate, or bacterial vaginosis (BV) as based on Gram staining of vaginal smears, the viable counts of lactobacilli (L. gasseri) and of streptococci‐staphylococci combined were highest in the intermediate group. In BV, particularly the high concentrations of Actinomyces urogenitalis, Atopobium vaginae, and Peptoniphilus harei were noted (≥1011 per ml). The total viable counts correlated with both cervical IL‐1α and IL‐1β. A strong negative correlation was observed between L. iners and total viable counts, G. vaginalis, or cervical IL‐1α, while it correlated positively with SLPI. Analysis of vaginal and cervical samples from 26 out of the 34 women by CDH showed that anaerobic bacteria were more frequently detected by CDH compared to culture. By this method, A. vaginae correlated with G. vaginalis, and L. iners with S. aureus. With regard to cytokines, B. ureolyticus correlated with both cervical and vaginal IL‐1α as well as with cervical IL‐8, while F. nucleatum, S. agalactiae, S. anginosus, or S. aureus correlated with vaginal IL‐1α. Furthermore, all Gram‐negative bacteria taken together, as measured by CDH, correlated with vaginal endotoxin and inversely with vaginal SLPI. The significance of the results is discussed. In summary, mapping of the identity and quantity of vaginal bacterial species and their association with locally produced host innate immune factors will help in defining various types of abnormal vaginal microbiota, developing new ways of assessing the risk of ascending subclinical infections, and in treating them. CDH appears to be a suitable tool for future analyses of large numbers of clinical samples with an extended number of bacterial probes.
Signet ring cell carcinoma of the eyelid – the monocle tumour
Authors: MORTENSEN ANOUCK LEUBA , HEEGAARD STEFFEN , CLEMMENSEN OLE , PRAUSE JAN ULRIK
Published: April 2008

We report the clinical and histopathological characteristics of two cases of signet ring cell carcinoma of the eye lids, and discuss the histogenesis of this neoplasm. Two 72‐year‐old Caucasian males both presented with slowly growing tumours of the eyelids. The tumours were excised and specimens were examined using light‐ and transmission electron microscopic techniques. Clinically, the tumours infiltrated both eyelids on one side of the face with swelling and periocular inflammation, creating a monocle‐like appearance. Extensive clinical work‐up excluded periocular metastases. Histopathologically, the tumours were composed of rather bland cells with mainly histiocytoid morphology. A minor proportion had a signet ring cell appearance. The cytoplasmic inclusions giving the signet ring morphology were PAS‐ and colloidal iron positive. The tumour cells reacted with antibodies against cytokeratins, carcinoembryonic antigen, epithelial membrane antigen, gross cystic disease fluid protein‐15 and lysozyme. Transmission electron microscopy demonstrated tumour cells containing intracytoplasmic vacuoles lined by microvilli. The tumour cells aggregated in duct‐like clusters. A diagnosis of primary signet ring cell carcinoma was made in both cases. Histopathological, immunohistological and ultrastructural findings indicated that the tumours were of sweat gland origin.
The first major extended‐spectrum β‐lactamase outbreak in Scandinavia was caused by clonal spread of a multiresistant Klebsiella pneumoniae producing CTX‐M‐15
Authors: LYTSY BIRGITTA , SANDEGREN LINUS , TANO EVA , TORELL ERIK , ANDERSSON DAN I. , MELHUS ÅSA
Published: April 2008

Between May and December 2005, 64 multidrug‐resistant isolates of Klebsiella pneumoniae were detected from patients admitted to Uppsala University Hospital. This represented a dramatic increase in ESBL‐producing K. pneumoniae compared to previous years. To investigate the epidemiology and to characterize the resistance mechanisms of the isolates, a study was initiated. Antibiotic susceptibility was determined by means of the Etest and the disc diffusion method. Extended‐spectrum beta‐lactamase (ESBL) production was identified by clavulanic acid synergy test and confirmed with PCR amplification followed by DNA sequencing. DNA profiles of the isolates were examined with pulsed‐field gel electrophoresis (PFGE). All isolates were resistant or exhibited reduced susceptibility to cefadroxil, cefuroxime, cefotaxime, ceftazidime, aztreonam, piperacillin/tazobactam, ciprofloxacin, tobramycin, and trimethoprim‐sulfamethoxazole. They produced ESBL of the CTX‐M‐15 type, and the involvement of a single K. pneumoniae clone was shown. This is the first major clonal outbreak of multiresistant ESBL‐producing K. pneumoniae in Scandinavia. The outbreak demonstrates the epidemic potential of enterobacteria containing ESBLs of the CTX‐M type, even in a country with a relatively low selective pressure and a low prevalence of multiresistant bacteria.
Factors influencing RNA degradation by Thermus thermophilus polynucleotide phosphorylase
Authors: Falaleeva Marina V. , Chetverina Helena V. , Ugarov Victor I. , Uzlova Elena A. , Chetverin Alexander B.
Published: April 2008

At the optimal temperature (65 °C), Thermus thermophilus polynucleotide phosphorylase (Tth PNPase), produced in Escherichia coli cells and isolated to functional homogeneity, completely destroys RNAs that possess even a very stable intramolecular secondary structure, but leaves intact RNAs whose 3′ end is protected by chemical modification or by hybridization with a complementary oligonucleotide. This allows individual RNAs to be isolated from heterogeneous populations by degrading unprotected species. If oligonucleotide is hybridized to an internal RNA segment, the Tth PNPase stalls eight nucleotides downstream of that segment. This allows any arbitrary 5′‐terminal fragment of RNA to be prepared with a precision similar to that of run‐off transcription, but without the need for a restriction site. In contrast to the high Mg2+ requirements of mesophilic PNPases, Tth PNPase retains significant activity when the free Mg2+ concentration is in the micromolar range. This allows minimization of the Mg2+‐catalysed nonenzymatic hydrolysis of RNA when phosphorolysis is performed at a high temperature. This capability of Tth PNPase for fully controlled RNA phosphorolysis could be utilized in a variety of research and practical applications.
Biochemical characteristics of C‐terminal region of recombinant chitinase from Bacillus licheniformis– implication of necessity for enzyme properties
Authors: Chuang Hsu‐Han , Lin Hsu‐Yang , Lin Fu‐Pang
Published: April 2008

The functional and structural significance of the C‐terminal region of Bacillus licheniformis chitinase was explored using C‐terminal truncation mutagenesis. Comparative studies between full‐length and truncated mutant molecules included initial rate kinetics, fluorescence and CD spectrometric properties, substrate binding and hydrolysis abilities, thermostability, and thermodenaturation kinetics. Kinetic analyses revealed that the overall catalytic efficiency, kcat/Km, was slightly increased for the truncated enzymes toward the soluble 4‐methylumbelliferyl‐N‐N′‐diacetyl chitobiose or 4‐methylumbelliferyl‐N‐N″‐N‴‐triacetyl chitotriose or insoluble α‐chitin substrate. By contrast, changes to substrate affinity, Km, and turnover rate, kcat, varied considerably for both types of chitin substrates between the full‐length and truncated enzymes. Both truncated enzymes exhibited significantly higher thermostabilities than the full‐length enzyme. The truncated mutants retained similar substrate‐binding specificities and abilities against the insoluble substrate but only had approximately 75% of the hydrolyzing efficiency of the full‐length chitinase molecule. Fluorescence spectroscopy indicated that both C‐terminal deletion mutants retained an active folding conformation similar to the full‐length enzyme. However, a CD melting unfolding study was able to distinguish between the full‐length and truncated mutant molecules by the two phases of apparent transition temperatures in the mutants. These results indicate that up to 145 amino acid residues, including the putative C‐terminal chitin‐binding region and the fibronectin (III) motif of B. licheniformis chitinase, could be removed without causing a seriously aberrant change in structure and a dramatic decrease in insoluble chitin hydrolysis. The results of the present study provide evidence demonstrating that the binding and hydrolyzing of insoluble chitin substrate for B. licheniformis chitinase was not dependent solely on the putative C‐terminal chitin‐binding region and the fibronectin (III) motif.
A hydrophilic cation‐binding protein of Arabidopsis thaliana, AtPCaP1, is localized to plasma membrane via N‐myristoylation and interacts with calmodulin and the phosphatidylinositol phosphates PtdIns(3,4,5)P3 and PtdIns(3,5)P2
Authors: Nagasaki Nahoko , Tomioka Rie , Maeshima Masayoshi
Published: April 2008

A hydrophilic cation‐binding protein, PCaP1, was found to be stably bound to the plasma membrane in Arabidopsis thaliana. PCaP1 was quantified to account for 0.03–0.08% of the crude membrane fractions from roots and shoots. Its homologous protein was detected in several plant species. We investigated the mechanism of membrane association of PCaP1 by transient expression of fusion protein with green fluorescent protein. The amino‐terminal sequence of 27 residues of PCaP1 had a potential to localize the fusion protein with green fluorescent protein to the plasma membrane, and the substitution of Gly at position 2 with Ala resulted in the cytoplasmic localization of PCaP1. When PCaP1 was expressed in the in vitro transcription/translation system with [3H]myristic acid, the label was incorporated into PCaP1, but not into a mutant PCaP1 with Gly2 replaced by Ala. These results indicate that PCaP1 tightly binds to the plasma membrane via N‐myristoylation at Gly2. We examined the binding capacity with phosphatidylinositol phosphates (PtdInsPs), and found that PCaP1 selectively interacts with phosphatidylinositol 3,5‐bisphosphate and phosphatidylinositol 3,4,5‐triphosphate. Competition assay with the N‐terminal peptide and mutational analysis revealed that PCaP1 interacts with these two PtdInsPs at the N‐terminal part. Interaction of PCaP1 with the membrane and PtdInsPs was not altered in the presence of Ca2+ at physiological concentrations. Furthermore, calmodulin associated with PCaP1 in a Ca2+‐dependent manner, and its association weakened the interaction of PCaP1 with PtdInsPs. These results indicate that the N‐terminal part is essential for both N‐myristoylation and interaction with PtdInsPs, and that PCaP1 may be involved in intracellular signalling through interaction with PtdInsPs and calmodulin.
Activity of soluble OX40 ligand is enhanced by oligomerization and cell surface immobilization
Authors: Müller Nicole , Wyzgol Agnes , Münkel Sabine , Pfizenmaier Klaus , Wajant Harald
Published: April 2008

OX40 ligand (OX40L) and OX40 are typical members of the tumor necrosis factor ligand family and the tumor necrosis factor receptor superfamily, respectively, and are involved in the costimulation and differentiation of T cells. Like other tumor necrosis factor ligands, OX40L is a type II transmembrane protein. Recombinant soluble human OX40L assembles into trimers and is practically inactive despite binding to OX40. However, oligomerization of soluble OX40L trimers by cross‐linking with antibodies or by expression as a hexameric fusion protein strongly increased the activity of the ligand. Moreover, a fusion protein of OX40L with a single chain fragment recognizing the tumor stroma antigen fibroblast activation protein showed a cell surface antigen‐dependent increase in the activity of the ligand domain of the molecule and thus mimicked the activity of membrane OX40L upon antigen binding. Trimeric single chain OX40L fusion proteins therefore represent a novel type of OX40L‐derived immunostimulatory molecule with potentially reduced systemic side effects.
AKAP12 in astrocytes induces barrier functions in human endothelial cells through protein kinase Cζ
Authors: Choi Yoon Kyung , Kim Kyu‐Won
Published: April 2008

Interactions between astrocytes and blood vessels are essential for the formation and maintenance of the blood–neural barrier (BNB). Astrocyte‐derived A‐kinase anchor protein 12 (AKAP12) influences BNB formation, but the mechanism of regulation of BNB functions by AKAP12 is not fully understood. We have defined a new pathway of barriergenesis in human retina microvascular endothelial cells (HRMECs) involving astrocytic AKAP12. Treatment of HRMECs with conditioned media from AKAP12‐overexpressing astrocytes reduced phosphorylation of protein kinase Cζ (PKCζ), decreased the levels of vascular endothelial growth factor (VEGF) mRNA and protein, and increased thrombospondin‐1 (TSP‐1) levels, which led to antiangiogenesis and barriergenesis. Transfection of a small interference RNA targeting PKCζ decreased VEGF levels and increased TSP‐1 levels in HRMECs. Rho is a putative downstream signal of PKCζ, and inhibition of Rho kinase with a specific inhibitor, Y27632, decreased VEGF levels and increased TSP‐1 levels. We therefore suggest that AKAP12 in astrocytes differentially regulates the expression of VEGF and TSP‐1 via the inhibition of PKCζ phosphorylation and Rho kinase activity in HRMECs.
Understanding Smoking Cessation in Rural Communities
Authors: Hutcheson Tresza D. , Greiner K. Allen , Ellerbeck Edward F. , Jeffries Shawn K. , Mussulman Laura M. , Casey Genevieve N.
Published: April 2008

ABSTRACT: 
Context:

Rural communities are adversely impacted by increased rates of tobacco use. Rural residents may be exposed to unique communal norms and other factors that influence smoking cessation. Purpose: This study explored facilitating factors and barriers to cessation and the role of rural health care systems in the smoking‐cessation process. Methods: Focus groups were conducted with smokers (N = 63) in 7 Midwestern rural communities. Qualitative analysis and thematic coding of transcripts was conducted. Findings: Three levels of pertinent themes—intrinsic, health‐system resource, and community/social factors—were identified. Intrinsic factors facilitating cessation included willingness to try various cessation methods, beliefs about consequences of continuing smoking (eg, smoking‐related illnesses), and benefits of quitting (eg, saving money). Intrinsic barriers included skepticism about resources, low self‐efficacy and motivation for smoking cessation, concern about negative consequences of quitting (eg, weight gain), and perceived benefits of continued smoking (eg, enjoyment). Key health‐system resource facilitators were pharmacotherapy use and physician visits. Resource barriers included infrequent physician visits, lack of medical/financial resources, limited local smoking‐cessation programs, and lack of knowledge of existing resources. In terms of community/social factors, participants acknowledged the negative social impact/image of smoking, but also cited a lack of alternative activities, few public restrictions, stressors, and exposure to other smokers as barriers to cessation. Conclusions: Smokers in rural communities face significant challenges that must be addressed. A multilevel model centered on improving access to health care system resources while addressing intrinsic and community/social factors might enhance smoking‐cessation interventions and programs in rural communities.
Kansas Primary Care Weighs In: A Pilot Randomized Trial of a Chronic Care Model Program for Obesity in 3 Rural Kansas Primary Care Practices
Authors: Ely Andrea C. , Banitt Angela , Befort Christie , Hou Qing , Rhode Paula C. , Grund Chrysanne , Greiner Allen , Jeffries Shawn , Ellerbeck Edward
Published: April 2008

ABSTRACT: Context:Obesity is a chronic disease of epidemic proportions in the United States. Primary care providers are critical to timely diagnosis and treatment of obesity, and need better tools to deliver effective obesity care.Purpose:To conduct a pilot randomized trial of a chronic care model (CCM) program for obesity care in rural Kansas primary care.Methods:We enrolled 107 participants to a 6‐month, 2‐armed, randomized trial comparing a CCM for obesity with usual care. The primary outcome was weight change at 90 days. The usual care arm received educational weight loss materials and outcome assessments at day 0, 90, and 180. The active arm received the same elements as the usual care arm plus a multicomponent obesity CCM.Findings:The Day 90 mean ± SD weight change for the active arm (n = 34) and control arm (n = 33), respectively, was −4.5 ± 7.7 pounds and −2.4 ± 8.1 pounds (P = .27 for difference). The Day 180 mean ± SD weight change for the active (n = 27) and control (n = 27) arms, respectively, was −9.4 ± 10.3 pounds and −2.1 ± 10.7 pounds (P = .01 for difference). There was no significant change in physical activity, or fruit and vegetable intake at day 90 or day 180.Conclusions:Improving the recognition and treatment of obesity in primary care settings is a critical initiative. Rural populations suffer disproportionately with obesity, and better methods of delivering obesity care are needed for this population. Further research is needed to establish the effectiveness of a CCM approach for obesity care.
The Occupational Mix Adjustment to the Medicare Hospital Wage Index: Why the Rural Impact Is Less Than Expected
Authors: Reiter Kristin L. , Slifkin Rebecca , Holmes George M.
Published: April 2008

ABSTRACT: Context:Rural hospitals are heavily dependent on Medicare for their long‐term financial solvency. A recent change to Medicare prospective payment system reimbursement—the occupational mix adjustment (OMA) to the wage index—has attracted a great deal of attention in rural policy circles.Purpose:This paper explores variation in the OMA across and within urban and rural markets. Reasons why the effect of the OMA has been less than some rural advocates anticipated are discussed.Methods:Data were obtained from the fiscal year 2007 Final Occupational Mix Survey Data Public Use File and the fiscal year 2007 Final Rule Wage Data Public Use File. Descriptive statistics were generated to determine the need for the OMA and the potential impact of its application on hospitals located in rural markets.Findings:The average OMA for nonmetropolitan markets is greater than 1, indicating that hospitals in these markets use a less‐skilled mix of labor than the national average. However, almost one third of nonmetropolitan markets had an OMA that was less than 1 and experienced a net decrease in Medicare reimbursement due to the OMA.Conclusions:There are several reasons why the impact of the OMA is smaller than many rural hospital administrators expected. The most important is that the adjustment happens at the market‐level rather than for individual hospitals, so a small hospital's staffing mix may have almost no effect on the final payment adjustment. In rural markets, it appears that hospitals in micropolitan areas exert a large influence on the OMA.
Medicare Hospital Charges in the Last Year of Life: Distribution by Quarter for Rural and Urban Nursing Home Decedents With Cognitive Impairment
Authors: Gessert Charles E. , Haller Irina V.
Published: April 2008

ABSTRACT: 
Background:

Medicare beneficiaries incur 27%‐30% of lifetime charges in the last year of life; most charges occur in the last quarter. Factors associated with high end‐of‐life Medicare charges include less advanced age, non‐white race, absence of advance directive, and urban residence. Methods: We analyzed Medicare hospital charges in the last year of life for nursing home residents with severe cognitive impairment, focusing on rural–urban differences. The study population consisted of 3,703 nursing home residents (1,882 rural, 1,821 urban) in Minnesota and Texas who died in 2000‐2001. Data on Medicare hospital charges were obtained from 1998‐2001 Centers for Medicare and Medicaid Services MedPAR files. Results: During the last year of life, unadjusted charges averaged $12,448 for rural subjects; $31,780 for urban. The charges were distributed across the last 4 quarters similarly for the 2 populations, with 15%‐20% of charges incurred in each of the first 3 quarters, and 47% (rural) and 52% (urban) in the last quarter. At the individual level, a higher percentage of hospital charges were incurred in the last 90 days by urban than by rural residents (P < .001). A larger proportion of urban (43%) than rural (37%) residents were hospitalized in the final quarter. The charges for hospitalized residents (N = 1,994) were distributed similarly to those of the entire study population. Discussion: Medicare hospital charges during the last year of life were lower for rural nursing home residents with cognitive impairment than for their urban counterparts. Charges tend to be more concentrated in the last 90 days of life for urban residents.
Rural–Urban Differences in Primary Care Physicians' Practice Patterns, Characteristics, and Incomes
Authors: Weeks William B. , Wallace Amy E.
Published: April 2008

ABSTRACT: 
Context:

Low salaries and difficult work conditions are perceived as a major barrier to the recruitment of primary care physicians to rural settings. Purpose: To examine rural–urban differences in physician work effort, physician characteristics, and practice characteristics, and to determine whether, after adjusting for any observed differences, rural primary care physicians' incomes were lower than those of urban primary care physicians. Methods: Using survey data from actively practicing office‐based general practitioners (1,157), family physicians (1,378), general internists (2,811), or pediatricians (1,752) who responded to the American Medical Association's annual survey of physicians between 1992 and 2002, we used linear regression modeling to determine the association between practicing in a rural (nonmetropolitan) or urban (standard metropolitan statistical area) setting and physicians' annual incomes after controlling for specialty, work effort, provider characteristics, and practice characteristics. Findings: Rural primary care physicians' unadjusted annual incomes were similar to their urban counterparts, but they tended to work longer hours, complete more patient visits, and have a much greater proportion of Medicaid patients. After adjusting for work effort, physician characteristics, and practice characteristics, primary care physicians who practiced in rural settings made $9,585 (5%) less than their urban counterparts (95% confidence intervals: −$14,569, −$4,602, P < .001). In particular, rural practicing general internists and pediatricians experienced lower incomes than did their urban counterparts. Conclusions: Addressing rural physicians' lower incomes, longer work hours, and greater dependence on Medicaid reimbursement may improve the ability to ensure that an adequate supply of primary care physicians practice in rural settings.
Expanding the Role of Nurse Practitioners: Effects on Rural Access to Care for Injured Workers
Authors: Sears Jeanne M. , Wickizer Thomas M. , Franklin Gary M. , Cheadle Allen D. , Berkowitz Bobbie
Published: April 2008

ABSTRACT: 
Context:

A 3‐year pilot program to expand the role of nurse practitioners (NPs) in the Washington State workers' compensation system was implemented in 2004 (SHB 1691), amid concern about disparities in access to health care for injured workers in rural areas. SHB 1691 authorized NPs to independently perform most functions of an attending physician. Purpose: The aims of this study were to (1) describe the contribution by NPs to Washington's workers' compensation provider workforce, (2) evaluate change in provider availability attributable to SHB 1691, and (3) evaluate the effect of SHB 1691 on timely accident report filing. Methods: Administrative data were used to evaluate this natural experiment, using a pre‐post design with primary care physicians (PCPs) as a nonequivalent comparison group. Findings: NPs served injured workers with characteristics similar to those served by PCPs, but 22.0% of NPs were rural, compared with 17.3% of PCPs. Of claimants with NPs as their attending provider, 53.3% were injured in a rural county, compared with 24.7% for those with PCP attending providers. The number of NPs participating in the workers' compensation system rose after SHB 1691 implementation, more so in rural areas. SHB 1691 implementation was associated with a 16 percentage point improvement in timely accident report filing by NPs in both rural and urban areas. Conclusions: Authorizing NPs to function as attending providers for injured workers may improve provider availability (especially in rural areas) and timely accident report filing, which in turn may improve worker outcomes and system costs.
Nonemergency Medicine‐Trained Physician Coverage in Rural Emergency Departments
Authors: Peterson Lars E. , Dodoo Martey , Bennett Kevin J. , Bazemore Andrew , Phillips Robert L.
Published: April 2008

ABSTRACT: 
Context: Rural areas have fewer physicians compared to urban areas, and rural emergency departments often rely on community or contracted providers for staffing. The emergency department workforce is composed of a variety of physician specialties and clinicians. Purpose: To determine the distribution of emergency department clinicians and the proportion of care they provide across the rural‐urban continuum. Methods: Cross‐sectional analysis of secondary data. The distribution of clinicians who provide emergency department care by county was determined using the 2003 Area Resource File. The percentage of emergency department care provided by clinician type was determined using 2003 Medicare claims data. Logistic regression analyses assessed the odds of being seen by different clinicians with a patient's rurality when presenting to the emergency department. Findings: Board‐certified emergency physicians provide 75% of all emergency department care, but only 48% for Medicare beneficiaries of the most rural of counties. The bulk of the remainder of emergency department care is largely provided by family physicians and general internists, with the percentage increasing with rurality. The likelihood of being seen by an emergency physician in the emergency department decreases 5‐fold as rurality increases, while being seen by a family physician increases 7‐fold. Conclusion: Nonemergency physicians provide a significant portion of emergency department care, particularly in rural areas. Medical specialties must cooperate to ensure the availability of high‐quality emergency department care to all Americans regardless of physician specialty.
Uninsured Hospitalizations: Rural and Urban Differences
Authors: Zhang Wanqing , Mueller Keith J. , Chen Li‐Wu
Published: April 2008

ABSTRACT: Context:Few studies have examined hospitalization patterns among the uninsured, especially from the perspective of rural and urban differences.Purpose:To examine whether the patterns of uninsured hospitalizations differ in rural and urban hospitals and to identify the most prevalent and costly diagnoses among uninsured hospitalizations.Methods:We conducted a cross‐sectional analysis of the Healthcare Cost and Utilization Project's National Inpatient Sample representing a total of 37,804,021 hospital discharges, with 4.9% of them generated by uninsured persons in 2002. We compared demographic and clinical characteristics and the proportion of frequent and costly diagnoses by rural and urban hospitals. We used multiple logistic regression models to examine the relationship between preventable conditions and rural and urban hospitals among uninsured hospitalizations.Findings:Uninsured persons discharged from rural hospitals were more likely than their urban counterparts to be working‐age adults (82% vs 79%) and to reside in a ZIP code area with a median household income of less than $35,000 per year (56% vs 26%). Rural uninsured hospitalizations were more likely to be for preventable conditions than were urban uninsured hospitalizations (P < .001). The proportion of total hospital charges related to preventable hospitalizations was 15.5% in rural hospitals versus 10.0% in urban hospitals.Conclusions:The patterns of uninsured hospitalizations in rural and urban hospitals were different in many ways. Providing adequate access to primary care could result in potential savings related to preventable hospitalizations for the uninsured, especially for rural hospitals.
Managing Drought Through Water Markets: Farmer Preferences in the Rio Grande Basin1
Authors: Hadjigeorgalis Ereney
Published: April 2008

Abstract:  Managing drought in agriculture has taken on growing importance as population growth and environmental concerns place increasing pressures on agricultural water use. One alternative for agricultural water resource management in areas of recurrent drought is allocation through market mechanisms. While past research has aimed to explain why farmers are reluctant to participate in already established water markets, this research seeks to identify the appropriate market mechanism given farmers’ preexisting attitudes toward water markets. Statistical analysis of survey data from 166 farmer interviews in the Rio Grande Basin indicate that farmers are significantly more likely to participate in short‐term water mechanisms, such as spot water markets and water banks than in permanent transfer mechanisms, particularly those that fully separate water rights from land. In sharp contrast to expectations, the choice of market mechanism did not differ significantly between farmers based on their a priori intention to buy, sell or both buy and sell in these markets. Choice of market mechanism also did not differ among farmer types although small, lifestyle or hobby farmers clearly preferred spot water markets to other types of short‐term mechanisms. Evaluating these attitudes a priori may help to design more suitable water market mechanisms for the basin.
Concentration‐Duration‐Frequency Curves for Stream Turbidity: Possibilities for Assessing Biological Impairment1
Authors: Schwartz John S. , Dahle Melanie , Bruce Robinson R.
Published: April 2008

Abstract:  Siltation and subsequent biological impairment is a national problem prompting state regulatory agencies to develop sediment total maximum daily loads (TMDL) for many streams. To support TMDL targets for reduced sediment yield in disturbed watersheds, a critical need exists for stream assessments to identify threshold concentrations of suspended sediment that impact aquatic biota. Because of the episodic nature of stream sediment transport, thresholds should not only be a function of sediment concentration, but also of duration and dose frequency. Water quality sondes can collect voluminous amounts of turbidity data, a surrogate for suspended sediment, at intervals that can be used to characterize concentration, duration, and frequency of elevated turbidity events. To characterize turbidity sonde data in an ecologically relevant manner, a methodology for concentration‐duration‐frequency (CDF) curves was developed using turbidity doses that relate to different levels of biological impairment. To illustrate this methodology, turbidity CDF curves were generated for two sites on Little Pigeon River in the Great Smoky Mountains National Park, Tennessee, using over 30,000 sonde data measurements per site for a one‐year period. Utilizing a Poisson arrival approach, turbidity spikes were analyzed stochastically by observing the frequency and duration of recorded events over a turbidity level that relates to a biological dose response. An exponential equation was used to fit duration and frequency of a specified turbidity level to generate concentric‐shaped CDF curves, where at specific turbidities longer durations occurred less frequently and conversely shorter durations occurred more frequently. The significance of the equation fit to the data was accomplished with a Kolmogorov‐Smirnov goodness‐of‐fit test. Our findings showed that the CDF curves derived by an exponential function performed reasonable well, with most curves significant at a 95% confidence level. These CDF curves were then used to demonstrate how they could be used to assess biological impairment, and identify future research needs for improved development of sediment TMDLs.
Ten new microsatellite markers for the buttonwood mangrove (Conocarpus erectus L., Combretaceae)
Authors: NETTEL ALEJANDRO , DODD RICHARD S. , CID‐BECERRA JORGE A. , DE LA ROSA‐VELEZ JORGE
Published: April 2008

We present 10 microsatellite markers for the buttonwood mangrove, Conocarpus erectus, a wide‐range mangrove associate species. Polymorphism was assessed among individuals from six different populations along the Pacific Coast of Mexico and Costa Rica, as well as in two individuals from the Yucatan Peninsula in the Atlantic. The number of alleles detected in the Pacific ranged from two to five. All loci amplified in the Yucatan samples and seven loci revealed a unique Atlantic allele. These markers will be useful for studies in the conservation of the species and to study the basic biology of C. erectus.
Isolation and characterization of microsatellite loci from the endangered New Zealand takahe (Gruiformes; Rallidae; Porphyrio hochstetteri)
Authors: GRUEBER CATHERINE E , KING TANIA M , WATERS JONATHAN M , JAMIESON IAN G
Published: April 2008

Nineteen polymorphic microsatellite loci were characterized from the endangered takahe (Porphyrio hochstetteri). Like many of New Zealand's other native avian species, levels of polymorphism were low, with variation detected at only 19 of 110 (17.3%) loci, and most polymorphic loci (78.9%) were diallelic (mean number of alleles = 2.3). Despite these low levels of variation, the microsatellites developed here will be useful for parentage assignment for confirming pedigrees, and investigating relationships between genetic variation, pedigree‐based inbreeding and reproductive success in this highly endangered species.
Microsatellite development suggests evidence of polyploidy in the social sponge‐dwelling snapping shrimp Zuzalpheus brooksi
Authors: RUBENSTEIN DUSTIN R. , MCCLEERY BRYNN V. , DUFFY J. EMMETT
Published: April 2008

We isolated and characterized 33 novel, polymorphic microsatellite loci from the social sponge‐dwelling snapping shrimp Zuzalpheus brooksi. We screened all 33 loci in approximately 31 individuals from a population of Z. brooksi from the Florida Keys, USA and found an average of 16 alleles per locus. Approximately 25% of the loci showed more than two bands per individual, suggesting evidence of high gene duplication, or more likely, polyploidy, which is common in crustaceans. The 25 disomic loci had an observed heterozygosity of 0.57 (range = 0.03–1.00) and will be useful for studying the social organization in Zuzalpheus shrimp.