bluuebunny/crossref_metadata_2025 huggingface dataset:
FITTING FRACTAL SURFACES ON NON-RECTANGULAR GRIDS
Authors: NAVASCUÉS M. A. , SEBASTIÁN M. V.
Published: June 2008

In a complex society, the visualization and interpretation of large amounts of data acquires an increasing importance. This can be done at once by means of two- or three-dimensional maps. To approach this problem, we undertake the construction of several variable fractal functions. In the first place, we introduce real fractal functions defined as perturbations of the classical ones. These basic mappings allow us to compute multidimensional approximations of experimental variables by means of linear combinations of products of fractal functions of Legendre type. The paper proposes a method of non-smooth representation for a large number of three-dimensional data on non-uniform grids. The procedures described are applied in the last part of the paper to the implementation of fitting maps for brain electrical activity.
The three-dimensional lithospheric structure of the Falkland Plateau region based on gravity modelling
Authors: KIMBELL GEOFFREY S. , RICHARDS PHILIP C.
Published: June 2008

The lithospheric structure of the Falkland Plateau region has been modelled by making an initial estimate on the basis of local isostasy and then refining the geometries by inversion of gravity anomalies. The model predicts a crustal thickness beneath the Falkland Plateau Basin that is more than twice that previously inferred from seismic evidence. The preferred explanation is that the seismic survey detected high-velocity (?underplated) lower crust rather than upper mantle. This is compatible with the results of deep seismic experiments over the conjugate Filchner Block of Antarctica and also appears likely on the basis of the position of the Falkland Plateau Basin in relation to the Karoo–Ferrar magmatic province at the time of extension. Continental crust is inferred to be continuous beneath the northern part of the Falkland Plateau, as there are consistent magnetic and flexural anomalies associated with the continent–ocean boundary. Flexural modelling of the southern margin of the plateau indicates lateral variations in strength, with the strongest lithosphere beneath the Falkland Plateau Basin. This may indicate thick oceanic crust beneath the southern part of the basin or the effect of thinning relatively weak continental crust and replacing it with relatively strong underplating.
U–Pb zircon dating of basement inliers within the Moine Supergroup, Scottish Caledonides: implications of Archaean protolith ages
Authors: FRIEND C.R.L. , STRACHAN R.A. , KINNY P.D.
Published: June 2008

Basement gneiss inliers within the Scottish Caledonides have been conventionally correlated with the Archaean Lewisian Gneiss Complex of the Caledonian foreland. Alternatively, the inliers could represent allochthonous terranes accreted to Laurentia before or during the Caledonian orogeny. Secondary ionization mass spectrometry U–Pb zircon dating indicates that the Ribigill, Borgie, Farr and Western Glenelg basement inliers are characterized by late Archaean protolith ages, and a period of isotopic disturbance in the late Palaeoproterozoic. The data are broadly consistent with correlation between the inliers and components of the Lewisian Gneiss Complex of the Caledonian foreland. The
c
. 2900 Ma protolith ages support correlation of the Borgie and Farr inliers with the Assynt terrane, and a younger,
c
. 2800 Ma age for the Ribigill inlier supports correlation with the Rhiconich terrane. None of the studied inliers shows a complete match of protolith and early metamorphic histories with any of the Lewisian basement terranes, but differences between the inliers and the foreland are no greater than those recorded within the foreland basement terranes themselves. Therefore, it remains probable that the dated inlier gneisses formed a distal part of the Laurentian margin prior to final telescoping during the Caledonian orogeny.
Fluid flow history from damage zone cements near the Dent and Rawthey faults, NW England
Authors: WOODCOCK N.H. , SAYERS N.J. , DICKSON J.A.D.
Published: June 2008

Fault-related breccias, in Carboniferous limestone, have been well documented in the footwall damage zone to the reverse-oblique Dent Fault. This study describes breccias in the more complicated hanging wall, hosted in pre-deformed Ordovician and Silurian lithologies along the Dent Fault or one of its splays such as the Rawthey Fault. Brecciation style is shown to be influenced by lithology, with the most extensive brecciation in mechanically strong units: siliceous or calcareous mudstone, cemented sandstone and fine tuff. Most brecciation involves dilational strain in the fault damage zones. Attritional breccias are rare, even in fault cores. Dilation breccias are cemented sporadically by quartz or barite, but mostly by carbonate minerals. Transition matrix analysis shows that the sequence of hanging-wall carbonate cements matches that in the footwall: first dolomite or calcite, then ferroan dolomite, then ferroan calcite. This similarity suggests hydrological connectivity from hanging wall to footwall and through tens of cubic kilometres across the Dent–Rawthey fault system. Such connectivity is predicted across upper crustal faults that cut strong mechanical stratigraphy. It is proposed that fluid flow though the fault system was driven mainly by syntectonic topography above the hanging wall, and possibly also by thermal convection caused by a buried granite pluton in the footwall.
Revised immunolocalization of the Na+-d-glucose cotransporter SGLT1 in rat organs with an improved antibody
Authors: Balen Daniela , Ljubojević Marija , Breljak Davorka , Brzica Hrvoje , Z̆lender Vilim , Koepsell Hermann , Sabolić Ivan
Published: June 2008

Previously, we characterized localization of Na+-glucose cotransporter SGLT1 ( Slc5a1) in the rat kidney using a polyclonal antibody against the synthetic COOH-terminal peptide of the rat protein (Sabolić I, Škarica M, Gorboulev V, Ljubojević M, Balen D, Herak-Kramberger CM, Koepsell H. Am J Physiol Renal Physiol 290: 913–926, 2006). However, the antibody gave some false-positive reactions in immunochemical studies. Using a shortened peptide for immunization, we have presently generated an improved, more specific anti-rat SGLT1 antibody (rSGLT1-ab), which in immunochemical studies with isolated membranes and tissue cryosections from male (M) and female (F) rats exhibited 1) in kidneys and small intestine, labeling of a major protein band of ∼75 kDa; 2) in kidneys of adult animals, localization of rSGLT1 to the proximal tubule (PT) brush-border membrane (S1 < S2 < S3) and intracellular organelles (S1 > S2 > S3), with zonal (cortex < outer stripe) and sex differences (M < F) in the protein expression, which correlated well with the tissue expression of its mRNA in RT-PCR studies; 3) in kidneys of castrated adult M rats, upregulation of the protein expression; 4) in kidneys of prepubertal rats, weak and sex-independent labeling of the 75-kDa protein band and immunostaining intensity; 5) in small intestine, sex-independent regional differences in protein abundance (jejunum > duodenum = ileum); and 6) thus far unrecognized localization of the transporter in cortical thick ascending limbs of Henle and macula densa in kidney, bile ducts in liver, enteroendocrine cells and myenteric plexus in the small intestine, and initial ducts in the submandibular gland. Our improved rSGLT1-ab may be used to identify novel sites of SGLT1 localization and thus unravel additional physiological functions of this transporter in rat organs.
Dexamethasone increases expression and activity of multidrug resistance transporters at the rat blood-brain barrier
Authors: Narang Vishal S. , Fraga Charles , Kumar Narendra , Shen Jun , Throm Stacy , Stewart Clinton F. , Waters Christopher M.
Published: June 2008

Brain edema is an important factor leading to morbidity and mortality associated with primary brain tumors. Dexamethasone, a synthetic glucocorticoid, is routinely prescribed with antineoplastic agents to alleviate pain associated with chemotherapy and reduce intracranial pressure. We investigated whether dexamethasone treatment increased the expression and activity of multidrug resistance (MDR) transporters at the blood-brain barrier. Treatment of primary rat brain microvascular endothelial cells with submicromolar concentrations of dexamethasone induced significantly higher levels of drug efflux transporters such as breast cancer resistance protein (abcg2), P-glycoprotein (P-gp; abcb1a/abcb1b), and MDR protein 2 (Mrp2; abcc2) as indicted by protein and mRNA levels as well as by functional activity. The effect of dexamethasone on transporter function was significant within 6 h of treatment, was dose dependent, and was reversible. Dexamethasone-induced upregulation of Bcrp and P-gp expression and function was partially abrogated by the glucocorticoid receptor (GR) antagonist RU486. In contrast, RU486 had no effect on the dexamethasone-induced upregulation of Mrp2, suggesting a GR-independent regulation of Mrp2, and a GR-dependent regulation of P-gp and Bcrp. In addition to the dexamethasone-induced upregulation of MDR transporters, we measured a dose-dependent and reversible increase in the expression of the nuclear transcription factor pregnane xenobiotic receptor (PXR). Administering dexamethasone to rats caused increased expression of PXR in brain microvessels within 24 h. These results suggest that adjuvant therapy with corticosteroids such as dexamethasone in the treatment of brain tumors may increase the expression of MDR transporters at the blood-brain barrier through pathways involving GR and PXR.
Moderate zinc restriction during fetal and postnatal growth of rats: effects on adult arterial blood pressure and kidney
Authors: Tomat Analía Lorena , Inserra Felipe , Veiras Luciana , Vallone María Constanza , Balaszczuk Ana María , Costa María Angeles , Arranz Cristina
Published: June 2008

Intrauterine and postnatal zinc restriction may result in an adverse environment for the development of cardiovascular and renal systems. This study evaluated the effects of moderate zinc deficiency during fetal life, lactation, and/or postweaning growth on systolic blood pressure, renal function, and morphology in adult life. Female Wistar rats received low (8 ppm) or control (30 ppm) zinc diets from the beginning of pregnancy up to weaning. After weaning, male offspring of each group of mothers were fed low or control zinc diet. Systolic blood pressure, creatinine clearance, proteinuria, renal morphology, renal apoptosis. and renal oxidative stress state were evaluated after 60 days. Zinc deficiency during pre- and postweaning growth induced an increase in systolic blood pressure and a decrease in the glomerular filtration rate associated with a reduction in the number and size of nephrons. Activation of renal apoptosis, reduction in catalase activity, glutathione peroxidase activity, and glutathione levels and increase in lipid peroxidation end products could explain these morphometric changes. Zinc deficiency through pre- and postweaning growth induced more pronounced renal alteration than postweaning zinc deficiency. These animals showed signs of renal fibrosis, proteinuria, increased renal apoptosis, and higher lipid peroxidation end products. A control diet during postweaning growth did not totally overcome renal oxidative stress damage, apoptosis, and fibrosis induced by zinc deficiency before weaning. In conclusion, zinc deficiency during a critical period of renal development and maturation could induce functional and morphological alterations that result in elevated blood pressure and renal dysfunction in adult life.
Cation transport activity of anion exchanger 1 mutations found in inherited distal renal tubular acidosis
Authors: Walsh Stephen , Borgese Franck , Gabillat Nicole , Unwin Robert , Guizouarn Helene
Published: June 2008

Anion exchanger 1 (AE1) is encoded by SLC4A1 and mediates electroneutral anion exchange across cell membranes. It is the most abundant protein in the red cell membrane, but it is also found in the basolateral membrane of renal α-intercalated cells, where it is required for normal urinary acidification. Recently, four point mutations in red cell AE1 have been described that convert the anion exchanger to a cation conductance. SLC4A1 mutations can also cause type 1 hypokalemic distal renal tubular acidosis (dRTA). We investigated the properties of four dRTA-associated AE1 mutations (R589H, G609R, S613F, and G701D) by heterologous expression in Xenopus laevis oocytes. Although these AE1 mutants are functional anion exchangers, unlike the red cell disease mutants, we found that they also demonstrated a cation leak. We found a large cation leak in the G701D mutant. This mutant normally requires coexpression with glycophorin A for surface membrane expression in red blood cells and oocytes. However, we found that coexpressing wild-type kidney AE1 with G701D in oocytes still caused a cation leak, consistent with heterodimerized G701D reaching the cell membrane and retaining its cation conductance property. These findings have potential structural and functional implications for AE1, and they indicate that while anion exchange and cation conductance properties are distinct, they can coexist.
Rosiglitazone improves aortic arginine transport, through inhibition of PKCα, in uremic rats
Authors: Ingbir Merav , Schwartz Idit F. , Shtabsky Alexander , Filip Irina , Reshef Ran , Chernichovski Tamara , Levin-Iaina Nomi , Rozovski Uri , Levo Yoram , Schwartz Doron
Published: June 2008

Peroxisome proliferator-activated receptor (PPAR) agonists were shown to inhibit atherosclerosis through augmentation of endothelial nitric oxide synthase (eNOS) activity. In addition, rosiglitazone exerts a beneficial effect in chronic renal failure (CRF). Since l-arginine transport by CAT-1 (the specific arginine transporter for eNOS) is inhibited in uremia, we aimed to explore the effect of rosiglitazone on arginine transport in CRF. Arginine uptake by aortic rings was studied in control animals, rats, 6 wk following 5/6 nephrectomy (CRF) and rats with CRF treated with rosiglitazone. The decrease of arginine transport in CRF was prevented by rosiglitazone. Immunobloting revealed that CAT-1 protein was decreased in CRF but remained unchanged following rosiglitazone administration. Protein content of the membrane fraction of PKCα and phosphorylated CAT-1 increased significantly in CRF, effects that were prevented by rosiglitazone. PKCα phosphorylation was unchanged but significantly attenuated by rosiglitazone in CRF. Ex vivo administration of phorbol-12-myristate-13-acetate to rosiglitazone-treated CRF rats significantly attenuated the effect of rosiglitazone on arginine uptake. The decrease in cGMP response to carbamyl-choline (eNOS agonist) was significantly attenuated by rosiglitazone in CRF. Western blotting and immunohistochemistry analysis revealed that protein nitration was intensified in the endothelium of CRF rats and this was attenuated by rosiglitazone. In conclusion, rosiglitazone prevents the decrease in arginine uptake in CRF through both depletion and inactivation of PKCα. These findings are associated with restoration of eNO generation and attenuation of protein nitration and therefore may serve as a novel mechanism to explain the beneficial effects of rosiglitazone on endothelial function in uremia.
Salt-sensitive hypertension and cardiac hypertrophy in mice deficient in the ubiquitin ligase Nedd4-2
Authors: Shi Peijun P. , Cao Xiao R. , Sweezer Eileen M. , Kinney Thomas S. , Williams Nathan R. , Husted Russell F. , Nair Ramesh , Weiss Robert M. , Williamson Roger A. , Sigmund Curt D. , Snyder Peter M. , Staub Olivier , Stokes John B. , Yang Baoli
Published: June 2008

Nedd4-2 has been proposed to play a critical role in regulating epithelial Na+ channel (ENaC) activity. Biochemical and overexpression experiments suggest that Nedd4-2 binds to the PY motifs of ENaC subunits via its WW domains, ubiquitinates them, and decreases their expression on the apical membrane. Phosphorylation of Nedd4-2 (for example by Sgk1) may regulate its binding to ENaC, and thus ENaC ubiquitination. These results suggest that the interaction between Nedd4-2 and ENaC may play a crucial role in Na+ homeostasis and blood pressure (BP) regulation. To test these predictions in vivo, we generated Nedd4-2 null mice. The knockout mice had higher BP on a normal diet and a further increase in BP when on a high-salt diet. The hypertension was probably mediated by ENaC overactivity because 1) Nedd4-2 null mice had higher expression levels of all three ENaC subunits in kidney, but not of other Na+ transporters; 2) the downregulation of ENaC function in colon was impaired; and 3) NaCl-sensitive hypertension was substantially reduced in the presence of amiloride, a specific inhibitor of ENaC. Nedd4-2 null mice on a chronic high-salt diet showed cardiac hypertrophy and markedly depressed cardiac function. Overall, our results demonstrate that in vivo Nedd4-2 is a critical regulator of ENaC activity and BP. The absence of this gene is sufficient to produce salt-sensitive hypertension. This model provides an opportunity to further investigate mechanisms and consequences of this common disorder.
Seychelles Lagoon Provides Corals with a Refuge from Bleaching
Authors: Iluz David , Vago Razi , Chadwick Nanette E. , Hoffman Razi , Dubinsky Zvy
Published: June 2008

An extensive bleaching event in the summer of the year 1997-1998 affected most reefs along East Africa's shores. In the aftermath of that episode, the reefs of Île Alphonse in the Seychelles were examined and it was found that reefs along the seaward slopes of the island lost >95% of their branching coral colonies, with considerably higher survival of massive species. Île Alphonse features a nearly circular shallow lagoon, with steep seaward slopes. Contrary to our expectations, mortality in the warmer lagoon was far lower than of coral colonies on the surrounding slopes, bathed in deeper and cooler waters. We suggest that corals in the lagoon were protected from UV radiation by leachate stemming from seagrass leaves steeped in the lagoon. Our measurements in the lagoon showed a strong attenuation of ultraviolet radiation, not observed in the waters outside the lagoon, and laboratory examination confirmed that the strong UV absorption of substances leached into seawater from decomposing leaves of the seagrassThalassodendron (=Cymodocea) testudinaceum. Our findings demonstrate the synergism between elevated seawater temperature and UV radiation in triggering bleaching on shallow reefs.
Genome-Based Construction of the Metabolic Pathways ofOrientia tsutsugamushiand Comparative Analysis within the Rickettsiales Order
Authors: Min Chan-Ki , Yang Jae-Seong , Kim Sanguk , Choi Myung-Sik , Kim Ik-Sang , Cho Nam-Hyuk
Published: June 2008

Orientia tsutsugamushi, the causative agent of scrub typhus, is an obligate intracellular bacterium that belongs to the order of Rickettsiales. Recently, we have reported thatO. tsutsugamushihas a unique genomic structure, consisting of highly repetitive sequences, and suggested that it may provide valuable insight into the evolution of intracellular bacteria. Here, we have used genomic information to construct the major metabolic pathways ofO. tsutsugamushiand performed a comparative analysis of the metabolic genes and pathways ofO. tsutsugamushiwith other members of the Rickettsiales order. WhileO. tsutsugamushihas the largest genome among the members of this order, mainly due to the presence of repeated sequences, its metabolic pathways have been highly streamlined. Overall, the metabolic pathways ofO. tsutsugamushiwere similar toRickettsiabut there were notable differences in several pathways including carbohydrate metabolism, the TCA cycle, and the synthesis of cell wall components as well as in the transport systems. Our results will provide a useful guide to the postgenomic analysis ofO. tsutsugamushiand lead to a better understanding of the virulence and physiology of this intracellular pathogen.
Modulation of the expression of the invasion-suppressor CRMP-1 by cyclooxygenase-2 inhibition via reciprocal regulation of Sp1 and C/EBPα
Authors: Wu Cheng-Chung , Lin Jau-Chen , Yang Shuenn-Chen , Lin Chiu-Wen , Chen Jeremy J.W. , Shih Jin-Yuan , Hong Tse-Ming , Yang Pan-Chyr
Published: June 2008

Collapsin response mediator protein-1 (CRMP-1) controls neural development and axonal growth but also acts as a cancer invasion suppressor. In this study, we investigated the transcriptional regulation of CRMP-1 expression. Using a serial deletion strategy, we identified a basal promoter region between nucleotides -100 and -180 in the 5′ flanking region of CRMP-1 (nucleotides -1,920 to +50) that contains multiple putative Sp1 and C/EBPα sites. Site-directed mutagenesis and deletion analysis revealed that the two C/EBPα sites, from nucleotides -122 to -133 and from nucleotides -101 to -113, are the most important regulatory elements. Gel-shift and antibody supershift assays showed that Sp1 protein was also present at this C/EBPα site, which overlaps with a Sp1 site. Overexpression of Sp1 decreased CRMP-1 promoter activity and protein expression, whereas overexpression of C/EBPα produced the opposite effect. Chromatin immunoprecipitation assays confirmed that Sp1 and C/EBPα compete for binding at the overlapping C/EBPα and Sp1 sites and reciprocally regulate CRMP-1 expression. Overexpression of cyclooxygenase-2 (COX-2) decreased CRMP-1 mRNA and protein expression. Conversely, the COX-2 inhibitor, celecoxib, induced a dose-dependent increase in CRMP-1 expression. COX-2 inhibition also decreased Sp1-DNA complex formation and inhibited cell invasion. We conclude that transcription of the invasion suppressor, CRMP-1, is reciprocally regulated at the promoter region by C/EBPα and Sp1. COX-2 inhibitors increase CRMP-1 expression by inhibiting Sp1-DNA complex formation and enhancing DNA binding of C/EBPα at the promoter. [Mol Cancer Ther 2008;7(6):1365–75]
Continuous Positive Airway Pressure and Surfactant
Authors: Bohlin Kajsa , Jonsson Baldvin , Gustafsson Ann-Sofi , Blennow Mats
Published: June 2008

Nasal continuous positive airway pressure (nCPAP) is an effective treatment of respiratory distress syndrome. Due to long-standing experience of early nCPAP as the primary respiratory support option in preterm infants, this approach is sometimes labeled ‘the Scandinavian Model’. Mechanical ventilation is potentially harmful to the immature lungs and cohort studies have demonstrated that centers using more CPAP and less mechanical ventilation have reduced rates of bronchopulmonary dysplasia. However, there is a lack of evidence in the form of larger, randomized controlled trials to prove the superiority of either method. Surfactant is essential in the treatment of respiratory distress syndrome and has generally been reserved for infants on mechanical ventilation. With the development of INSURE (INtubation SURfactant Extubation), in which surfactant is administered during a brief intubation followed by immediate extubation, surfactant therapy can be given during nCPAP treatment further reducing need for mechanical ventilation. In this review the history, current knowledge and techniques of CPAP and surfactant are discussed.
Prevalence of Type 2 Diabetes Mellitus among Kuwaiti Children and Adolescents
Authors: Moussa Mohamed A.A. , Alsaeid Mayra , Abdella Nabila , Refai Thanaa M.K. , Al-Sheikh Nashami , Gomez Joseph E.
Published: June 2008

Objectives: To determine the prevalence of type 2 diabetes among 6- to 18-year-old Kuwaiti children. Subjects and Methods: Children with type 2 diabetes were identified at 182 schools (50 primary, 63 intermediate, and 69 secondary) randomly selected using the 2000/2001 educational districts’ registers as a sampling frame. Prevalence rates were adjusted to the 2002 Kuwaiti population. Diagnosis of type 2 diabetes was based on the World Health Organization and the American Diabetes Association criteria. Results: Type 2 diabetes was identified in 45 of the 128,918 children surveyed, thereby giving an overall prevalence of 34.9 per 100,000 [95% confidence interval (CI) 24.7–45.1]. There was a significant difference in prevalence between males (47.3, 95% CI 28.7–65.8) and females (26.3, 95% CI 14.8–37.8) at p = 0.05 and a significant trend for an increase in prevalence of type 2 diabetes with age (p = 0.026). The overall age-adjusted prevalence rate in the 2002 Kuwaiti population was 33.2 (95% CI 26.6–39.9), 41.6 (95% CI 31.2–52.0) in male and 24.6 (95% CI 16.4–32.7) in female children; the difference was significant at p = 0.013. There was no significant difference in prevalence between regions. Children with type 2 diabetes had a significantly higher frequency (51.1%) of a positive family history of diabetes than children of a similar age without type 2 diabetes (22.2%) (p = 0.004). Conclusion: The prevalence of type 2 diabetes in adult Kuwaitis is spreading to children and adolescents, making it an emergency public health problem. Efforts need to be initiated to address prevention strategies of type 2 diabetes in youth.
Surgical Intervention for Gastrointestinal Foreign Bodies in Adults: A Case Series
Authors: Syrakos Theodoros , Zacharakis Emmanouil , Antonitsis Polichronis , Zacharakis Evangelos , Spanos Constantinos , Georgantis G. , Kiskinis Dimitrios
Published: June 2008

Objective: The aim of our study was to demonstrate our experience regarding the surgical treatment of complications after foreign body ingestion. Subject and Methods: From 1997 to 2005, we treated 16 adult patients (mean age 44.8 years, range 21–77), who presented with complications after foreign body ingestion. Results: The complications treated were perforation-peritonitis: n = 7 (44%), intra-abdominal abscess formation: n = 5 (31%), upper gastrointestinal bleeding: n = 3 (19%) and inflammatory mass formation: n = 1 (6%) patient. The diagnosis was made intra-operatively in 13 (81.3%) of the cases. The commonest anatomical position of the perforation was the large bowel, in 7 (43%) of the cases. Bony food parts were the commonest foreign bodies accidentally swallowed, in 9 (56%) patients. The median hospital stay was 7 days (2–18), while no death occurred in the postoperative period among the patients of the study. The postoperative morbidity rate was 22.2%. Conclusions: The most common complication after foreign body ingestion was the perforation of the gastrointestinal tract. The risk of perforation was higher when sharp foreign bodies were ingested. The pre-operative diagnosis was difficult, and it was usually achieved intra-operatively.
Value of Radiographic Esophageal Imaging in Determining an Optimal Atrial Septal Puncture Site for Percutaneous Balloon Mitral Valvuloplasty
Authors: Wu Tong-Guo , Wang Le-Xin , Chen Si-Wei , Lin Zi-Qing , Yan Cheng-Jun , Huang Li-Ping
Published: June 2008

Objective: To investigate the value of radiographic esophageal imaging in facilitating transseptal catheterization in patients undergoing percutaneous balloon mitral valvuloplasty. Subjects and Methods: A total of 468 patients were randomized into either the study group (n = 234), in which radiographic esophageal imaging by the oral administration of a contrast media took place, or the control group (n = 234), in which the Ross technique was used.Of the 468 patients, 203 were males and 265 were females. The average ages of the study and control groups were 53 ± 16 and 51 ± 17 years, respectively. The patients had severe left atrial enlargement, as measured using 2-dimensional echocardiography. Results: In the study group, the left atrial impression on the esophagus was clearly seen, and was used to identify the puncture site on the right atrial side for the passage of the transseptal catheter. In the control group, the left atrial silhouette was not clearly shown by fluoroscopy in 112 patients (47.5%). The success rate of transseptal catheterization in the study group was higher than in the control group (99.6 vs. 45.7%, p = 0.0001). There were no complications in the study group, but pericardial tamponade occurred in 1 patient in the control group. Conclusion: Radiographic esophageal imaging facilitates the identification of an optimal atrial transseptal puncture site, and improves the success rate of transseptal catheterization in patients undergoing percutaneous balloon mitral valvuloplasty.
Viral, Bacterial and Parasitic Etiology of Pediatric Diarrhea in Gaza, Palestine
Authors: Abu-Elamreen Farid H. , Abed Abdalla A. , Sharif Fadel A.
Published: June 2008

Objectives: To determine the etiology of acute diarrhea in Palestinian children under 5 years of age and to improve knowledge of the etiology of gastrointestinal pathogens using traditional and molecular diagnostic techniques. Materials and Methods: Various common enteropathogens (viral, bacterial and parasites) associated with diarrhea were investigated by conventional and molecular techniques (PCR) in 150 children less than 5 years of age admitted to the Central Pediatric Hospital, Gaza Strip, Palestine. Results: The occurrence of enteropathogens identified was as follows: rotavirus 42/150 (28%), Entamoeba histolytica/dispar 23/150 (15%), Shigella spp. 9/150 (6%), Campylobacter coli/jejuni and Escherichia coli O157:H7 7/150 (5%) each, Salmonella spp. 3/150 (2%), Giardia intestinalis 1/150 (1%), and Strongyloides stercoralis 1/150 (1%) of the samples. Shigella and Salmonella isolates were tested for their susceptibility to common antimicrobial agents and most of the isolates were resistant to ampicillin and trimethoprim/sulfamethoxazole. Conclusion: This study demonstrated that rotavirus, E. coli O157:H7 and Campylobacter, which are not routinely screened for in Gaza Strip, were significant enteropathogens. The results highlight the value of using a combination of traditional and PCR techniques in the diagnosis of enteropathogens related to gastroenteritis.
Self-Medication Practices among Diabetic Patients in Kuwait
Authors: Awad Abdelmoneim , Al-Rabiy Shahd , Abahussain Eman
Published: June 2008

Objectives: The aim of this study was to estimate the prevalence of self-medication with proprietary medicines and/or herbs among diabetic patients and evaluate factors associated with self-medication among diabetic patients. Subjects and Methods: A total of 104 diabetic patients were selected randomly from eight diabetic clinics from three governorates. Data were collected via face-to-face structured interview of the respondents in the clinics using a developed and piloted questionnaire. Results: The response rate was 96.2%. Seventy-four percent of the study participants reported that they seek medical consultation when they get an illness, 92% indicated that they know that the use of medicines and/or herbs to treat an illness without a medical consultation can be harmful. Only 13% of the respondents reported that they had used medicine or herbs without medical consultation to treat an illness within the previous 2 months of the study period. Nine percent of the study population reported that they used herbs to treat diabetes, and 2% used them for other illness. Only two (2%) indicated that they used medicines, which were analgesics, diet pills and vitamins. There was no significant association between self-medication with medicines or herbs and the sociodemographic characteristics of the respondents (p > 0.05). Conclusion: The prevalence of self-medication with medicines, including herbs, among diabetic patients in Kuwait is low. Enforcement of a strict prescription policy and coverage of medical consultation and treatment by health insurance may have contributed to low self-medication practices among diabetic patients.
Synchronous Hodgkin’s Disease and Gastric Adenocarcinoma
Authors: Comez Gazi , Pehlivan Yavuz , Kalender Mehmet Emin , Sevinc Alper , Sari Ibrahim , Camci Celalettin
Published: June 2008

Background: Adenocarcinoma is the most frequent pathological type of stomach cancer. Hodgkin’s lymphoma is a lymphoproliferative disease arising from lymphoid tissue which is characterized by Reed-Sternberg cells. Synchronous occurrence of these two malignancies has not been reported in the English literature so far. Case: Here we present a 52-year-old male complaining of epigastric pain and fever diagnosed as stomach adenocarcinoma and Hodgkin’s lymphoma. Conclusion: It is thought that this case is the first of a synchronous stomach adenocarcinoma and Hodgkin’s lymphoma encountered in the English literature. It should be kept in mind that second malignancies can be seen in mass lesions in patients diagnosed with cancer.
Response of a Patient with Pleural and Peritoneal Mesothelioma after Second-Line Chemotherapy with Lipoplatin and Gemcitabine
Authors: Karpathiou Georgia , Argiana Evangelia , Koutsopoulos Anastassios , Froudarakis Marios E.
Published: June 2008

We report the case of a 56-year-old patient with malignant pleural mesothelioma of epithelial type, who responded to second-line chemotherapy with lipoplatin plus gemcitabine. Diagnosis and staging of the disease was done by medical thoracoscopy with biopsies of the right pleura in December 2003, when he was treated with talc pleurodesis. Eighteen months later, he presented with pleural effusion of the left side and underwent first-line chemotherapy with cisplatin plus vinorelbine. After 8 cycles, the patient presented renal toxicity limiting further cisplatinum chemotherapy and disease progression with peritoneal invasion of the tumor and ascites. Treatment with lipoplatin-gemcitabine was decided on in November 2006, and the patient showed important improvement in the clinical status and peritoneal effusion. He survived for 36 weeks, with symptom-free survival of 34 weeks.
Acoustic and Electroglottographic Voice Characteristics in Chronic Cough and Paradoxical Vocal Fold Movement
Authors: Vertigan Anne E. , Theodoros Deborah G. , Winkworth Alison L. , Gibson Peter G.
Published: June 2008

Objective: Chronic cough (CC) and paradoxical vocal fold movement (PVFM) may be associated with voice problems. Objective acoustic and electroglottographic (EGG) measures have the capacity to delineate these vocal characteristics. This study investigated acoustic and EGG voice features of CC and PVFM. Patients and Methods: Acoustic and EGG findings were compared among 5 groups of participants. The first 3 groups, CC (n = 56), PVFM (n = 8) and combined CC-PVFM (n = 55), included individuals with cough and respiratory symptoms that persisted despite medical treatment. Groups 4 and 5 included individuals with muscle tension dysphonia (n = 25) and healthy controls (n = 27). Results: Participants with CC/PVFM recorded reduced phonation times (p < 0.001), greater jitter (p < 0.001), reduced harmonic to noise ratio (p = 0.001), reduced phonation range (p = 0.007) and shorter closed phase of vocal fold vibration (p = 0.006) in comparison to healthy controls. Females with CC had reduced fundamental frequency in connected speech (p = 0.009). There was consistent overlap between the participants with CC and those with PVFM. Duration of closed phase and fundamental frequency were lower in the participants with CC and PVFM than in those with muscle tension dysphonia. Conclusion: These results confirm abnormalities in acoustic and EGG voice features in CC and PVFM.
Distinguishing Properties of Cells From the Myocardial Sleeves of the Pulmonary Veins
Authors: Jones Sandra A. , Yamamoto Mitsuru , Tellez James O. , Billeter Rudi , Boyett Mark R. , Honjo Haruo , Lancaster Matthew K.
Published: June 2008

Background—

A common source of arrhythmogenic spontaneous activity instigating atrial fibrillation is the myocardial tissue, or sleeves, at the base of the pulmonary veins. This study compared the properties of cells from the myocardial sleeves of the pulmonary veins (PV
m
) with cells from the normal cardiac pacemaker (the sinoatrial node) and regions of the atria. Our objective was to identify key features of these cells that predispose them to becoming the focus of cardiac arrhythmias.

Methods and Results—

Single cells were isolated from samples of rabbit PV
m
, central and peripheral sinoatrial node, crista terminalis, and left and right atria. Detailed morphology of cells was assessed and intracellular calcium concentrations measured with the use of Fluo-3. Cells from the PV
m
were smaller than atrial cells and showed large elevations in diastolic calcium during activation at physiological rates, a feature the PV
m
cells shared with cells from the sinoatrial node. Unstimulated spontaneous activity was observed in a minority of cells from the PV
m
, but numerous cells from this region showed spontaneous activity for a brief period immediately subsequent to stimulation at physiological rates. This was not observed in atrial cells. Assessment of calcium removal pathways showed sarcolemmal calcium extrusion in cells from the PV
m
to have a high reliance on “slow” extrusion pathways to maintain intracellular calcium homeostasis because of a low expression of sodium–calcium exchanger.

Conclusions—

We conclude that cells from the PV
m
share some features with cells from the sinoatrial node but also have distinctly unique features that predispose them to the development of spontaneous activity.
Day of Admission and Clinical Outcomes for Patients Hospitalized for Heart Failure
Authors: Fonarow Gregg C. , Abraham William T. , Albert Nancy M. , Gattis Stough Wendy , Gheorghiade Mihai , Greenberg Barry H. , O’Connor Christopher M. , Nunez Eduardo , Yancy Clyde W. , Young James B.
Published: June 2008

Background—

Differences in hospital staffing may influence outcomes for patients with acute conditions, including heart failure (HF), depending on which day of the week the patients are admitted. This study examined the relationship between the day of the week patients are hospitalized for HF and death rate, length of stay (LOS), and rehospitalization rate.

Methods and Results—

A total of 259 US hospitals participating in the Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients With Heart Failure (OPTIMIZE-HF) submitted data on 48 612 patients with HF. Sixty- to 90-day postdischarge follow-up data were collected prospectively in a prespecified 10% sample. We analyzed day of admission and discharge, demographic, medical history, medication use, laboratory, and in-hospital procedure data for their association with hospital LOS and death rate. Patient characteristics were similar for weekday and weekend presentation. LOS was a median of 4.0 days and a mean of 5.7�5.7 days; in-hospital death rate was 3.8%. In-hospital and postdischarge risk of death were similar for each day of the week in the hospital and follow-up cohorts, respectively. LOS, however, was significantly influenced by day of admission, even after adjustment for other LOS risk factors. The shortest LOS by admission day of the week was Tuesday (5.39 days), and the longest was Friday (5.88 days;
P
<0.001).

Conclusions—

No differences in death rate by day of admission or discharge for HF hospitalizations were evident. Hospitalizations for HF on Thursday and Friday were associated with prolonged LOS. Understanding the factors responsible for the increased LOS and potential adjustments in staffing to facilitate weekend discharges may improve the efficiency of HF hospital care.
Aging and Disease as Modifiers of Efficacy of Cell Therapy
Authors: Dimmeler Stefanie , Leri Annarosa
Published: June 2008

Cell therapy is a promising option for treating ischemic diseases and heart failure. Adult stem and progenitor cells from various sources have experimentally been shown to augment the functional recovery after ischemia, and clinical trials have confirmed that autologous cell therapy using bone marrow—derived or circulating blood–derived progenitor cells is safe and provides beneficial effects. However, aging and risk factors for coronary artery disease affect the functional activity of the endogenous stem/progenitor cell pools, thereby at least partially limiting the therapeutic potential of the applied cells. In addition, age and disease affect the tissue environment, in which the cells are infused or injected. The present review article will summarize current evidence for cell impairment during aging and disease but also discuss novel approaches how to reverse the dysfunction of cells or to refresh the target tissue. Pretreatment of cells or the target tissue by small molecules, polymers, growth factors, or a combination thereof may provide useful approaches for enhancement of cell therapy for cardiovascular diseases.
Just-in-Time Connectivity for Large Spiking Networks
Authors: Lytton William W. , Omurtag Ahmet , Neymotin Samuel A. , Hines Michael L.
Published: June 2008

The scale of large neuronal network simulations is memory limited due to the need to store connectivity information: connectivity storage grows as the square of neuron number up to anatomically relevant limits. Using the NEURON simulator as a discrete-event simulator (no integration), we explored the consequences of avoiding the space costs of connectivity through regenerating connectivity parameters when needed: just in time after a presynaptic cell fires. We explored various strategies for automated generation of one or more of the basic static connectivity parameters: delays, postsynaptic cell identities, and weights, as well as run-time connectivity state: the event queue. Comparison of the JitCon implementation to NEURON's standard NetCon connectivity method showed substantial space savings, with associated run-time penalty. Although JitCon saved space by eliminating connectivity parameters, larger simulations were still memory limited due to growth of the synaptic event queue. We therefore designed a JitEvent algorithm that added items to the queue only when required: instead of alerting multiple postsynaptic cells, a spiking presynaptic cell posted a callback event at the shortest synaptic delay time. At the time of the callback, this same presynaptic cell directly notified the first postsynaptic cell and generated another self-callback for the next delay time. The JitEvent implementation yielded substantial additional time and space savings. We conclude that just-in-time strategies are necessary for very large network simulations but that a variety of alternative strategies should be considered whose optimality will depend on the characteristics of the simulation to be run.
Indices for Testing Neural Codes
Authors: Victor Jonathan D. , Nirenberg Sheila
Published: June 2008

One of the most critical challenges in systems neuroscience is determining the neural code. A principled framework for addressing this can be found in information theory. With this approach, one can determine whether a proposed code can account for the stimulus-response relationship. Specifically, one can compare the transmitted information between the stimulus and the hypothesized neural code with the transmitted information between the stimulus and the behavioral response. If the former is smaller than the latter (i.e., if the code cannot account for the behavior), the code can be ruled out.

The information-theoretic index most widely used in this context is Shannon's mutual information. The Shannon test, however, is not ideal for this purpose: while the codes it will rule out are truly nonviable, there will be some nonviable codes that it will fail to rule out. Here we describe a wide range of alternative indices that can be used for ruling codes out. The range includes a continuum from Shannon information to measures of the performance of a Bayesian decoder. We analyze the relationship of these indices to each other and their complementary strengths and weaknesses for addressing this problem.
Deep, Narrow Sigmoid Belief Networks Are Universal Approximators
Authors: Sutskever Ilya , Hinton Geoffrey E.
Published: June 2008

In this note, we show that exponentially deep belief networks can approximate any distribution over binary vectors to arbitrary accuracy, even when the width of each layer is limited to the dimensionality of the data. We further show that such networks can be greedily learned in an easy yet impractical way.
Improved Daytime Column-Integrated Precipitable Water Vapor from Vaisala Radiosonde Humidity Sensors
Authors: Cady-Pereira K. E. , Shephard M. W. , Turner D. D. , Mlawer E. J. , Clough S. A. , Wagner T. J.
Published: June 2008

Accurate water vapor profiles from radiosondes are essential for long-term climate prediction, weather prediction, validation of remote sensing retrievals, and other applications. The Vaisala RS80, RS90, and RS92 radiosondes are among the more commonly deployed radiosondes in the world. However, numerous investigators have shown that the daytime water vapor profiles measured by these instruments present a significant dry bias due to the solar heating of the humidity sensor. This bias in the column-integrated precipitable water vapor (PWV), along with variability due to calibration, can be removed by scaling the humidity profile to agree with the PWV retrieved from a microwave radiometer (MWR), as has been demonstrated by several previous studies. Infrared radiative closure analyses have shown that the MWR PWV does not present daytime versus nighttime differences; thus, scaling by the MWR is a possible approach for removing the daytime dry bias. However, MWR measurements are not routinely available at all radiosonde launch sites. Starting from a long-term series of sonde and MWR PWV measurements from the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site, the authors have developed a simple correction to the column-integrated sonde PWV, derived from an analysis of the ratio of the MWR and sonde measurements; this correction is a function of the atmospheric transmittance as determined by the solar zenith angle, and it effectively removes the daytime dry bias at all solar zenith angles. The correction was validated by successfully applying it to an independent dataset from the ARM tropical western Pacific (TWP) site.
Representation Error of Oceanic Observations for Data Assimilation
Authors: Oke Peter R. , Sakov Pavel
Published: June 2008

A simple approach to the estimation of representation error (RE) of sea level (η), temperature (T), and salinity (S) observations for ocean data assimilation is described. It is assumed that the main source of RE is due to unresolved processes and scales in the model. Therefore, RE is calculated as a function of model resolution. The methods described here exploit the availability of mapped sea level anomalies (mSLAs) and along-track sea level anomalies (atSLAs). The mSLA fields or atSLA observations are regarded as the true ocean state. Here, they are averaged according to the resolution of the model grid, and the averaged field is taken as a representation of the true state on the given grid. The difference between the original data and the averaged field is then regarded as the RE for η. Subsequently, the RE is projected for η over depth using a standard technique, giving an estimate of the RE for T and S. Examples of RE estimates for an intermediate- and high-resolution global grid are presented. It is found that there is significant spatial variability in the RE for η, T, and S, with values that are typically greater than or comparable to measurement error, particularly in regions of strong mesoscale variability.