bluuebunny/crossref_metadata_2025 huggingface dataset:
π-ELECTRONS IN A SINGLE STRAND OF DNA: A PHENOMENOLOGICAL APPROACH
Authors: IGUCHI KAZUMOTO
Published: July 2004

We revisit the problem of the electronic properties of a single strand of DNA, formulating the Hückel approximation for π-electrons in both the sugar-phosphate backbone chain and the π-stacking of nitrogenous bases in a single strand of DNA where the nitrogenous bases are adenine (A), guanine (G), cytosine (C) and thymine (T), respectively. We calculate the electronic band structure of π-electrons: (i) in the single nitrogenous base molecules such as A, G, C and T, (ii) in the single sugar-phosphate molecule, (iii) in the single nucleotide systems such as A, G, C, T with the single sugar-phosphate group, and (iv) in the system of a single strand of DNA with an infinite repetition of a nucleotide such as A, G, C and T, respectively. We find the following: In the case of (i), there is an energy gap between the energy levels for the HOMO and LUMO in the nitrogenous base. This guarantees the semiconducting character of the bases as a mother material. In the case of (ii), there are the HOMO localized at the oxygen site with a double bond and the LUMO localized around the phosphorus atom, which have a quite large energy gap. In the case of (iii), the energy levels for the HOMO and LUMO of the nitrogenous base remain almost the same as those of the nucleotide, while those of the sugar-phosphate group remain the same as well. The HOMO of the sugar-phosphate group exists right below the HOMO of the nitrogenous base. Therefore, comparing the energy levels for the HOMOs of the nitrogenous base group with those of the sugar-phosphate group, the nitrogenous base group behaves as a donor while the sugar-phosphate group behaves as an acceptor. In the case of (iv), there are energy bands and band gaps for the extended states in the nitrogenous base group and the sugar-phosphate group as well as the discrete levels for the localized states at the phosphate site in the spectrum. There is a transition from semiconductor to semimetal as the π-electron hopping between the nitrogenous bases of nucleotide is increased. The details of the above will be discussed in the present paper. Thus, we show the powerfulness of the Hückel theory in the study of DNA as well, although this theory is, at the first glance, oversimplified and purely phenomenological.
PROSODY AND THE MUSIC OF THE HUMAN SPEECH
Authors: D'AUTILIA ROBERTO
Published: July 2004

We propose the use of a self-oscillating dynamical system — the pre-Galileian clock equation — for modeling the laryngeal tone. The parameters are shown to be the minimal control needed for generating the prosody of the human speech. Based on this model, we outline a peak delay detection algorithm for extracting the prosody of the real speech.
PARAMETER MISMATCHES AND INVERSE SYNCHRONIZATION IN THE IKEDA MODEL
Authors: SHAHVERDIEV E. M. , NURIEV R. A. , HASHIMOV R. H.
Published: July 2004

We investigate inverse retarded synchronization between two uni-directionally linearly coupled chaotic non-identical Ikeda models and show that parameter mismatches are of crucial importance to achieve synchronization. We establish that independent of the relation between the delay time in the coupled systems and the coupling delay time, only inverse retarded synchronization with the coupling delay time is obtained. We derive existence and stability conditions for the inverse retarded synchronization manifold. We show that with parameter mismatch or without it neither inverse complete nor inverse anticipating synchronization occurs. Numerical simulations fully support the analytical approach.
Electroneutral sodium absorption and electrogenic anion secretion across murine small intestine are regulated in parallel
Authors: Gawenis Lara R. , Hut Hans , Bot Alice G. M. , Shull Gary E. , de Jonge Hugo R. , Stien Xavier , Miller Marian L. , Clarke Lane L.
Published: July 2004

Electrolyte transport processes of small intestinal epithelia maintain a balance between hydration of the luminal contents and systemic fluid homeostasis. Under basal conditions, electroneutral Na+absorption mediated by Na+/H+exchanger 3 (NHE3) predominates; under stimulated conditions, increased anion secretion mediated by CFTR occurs concurrently with inhibition of Na+absorption. Homeostatic adjustments to diseases that chronically affect the activity of one transporter (e.g., cystic fibrosis) may include adaptations in the opposing transport process to prevent enterosystemic fluid imbalance. To test this hypothesis, we measured electrogenic anion secretion (indexed by the short-circuit current) across NHE3-null [NHE3(−)] murine small intestine and electroneutral Na+absorption (by radioisotopic flux analysis) across small intestine of mice with gene-targeted disruptions of the anion secretory pathway, i.e., CFTR-null [CFTR(−)] or Na+-K+-2Cl−cotransporter-null [NKCC1(−)]. Protein expression of NHE3 and CFTR in the intestinal epithelia was measured by immunoblotting. In NHE3(−), compared with wild-type small intestine, maximal and bumetanide-sensitive anion secretion following cAMP stimulation was significantly reduced, and there was a corresponding decrease in CFTR protein expression. In CFTR(−) and NKCC1(−) intestine, Na+absorption was significantly reduced compared with wild-type. NHE3 protein expression was decreased in the CFTR(−) intestine but was unchanged in the NKCC1(−) intestine, indicating that factors independent of expression also downregulate NHE3 activity. Together, these data support the concept that absorptive and secretory processes determining NaCl and water movement across the intestinal epithelium are regulated in parallel to maintain balance between the systemic fluid volume and hydration of the luminal contents.
Functional effects of enhancing or silencing adenosine A2breceptors in cardiac fibroblasts
Authors: Chen Yinghong , Epperson Sara , Makhsudova Lala , Ito Bruce , Suarez Jorge , Dillmann Wolfgang , Villarreal Francisco
Published: July 2004

Cardiac fibroblasts (CF) express adenosine (ADO) receptors, and pharmacological evidence suggests the possible involvement of the A2(A2aand A2b) receptor (A2aR and A2bR) subtypes in inhibiting cell functions involved in fibrosis. The main objective of this study was to define the contributions of A2aand/or A2breceptors in modulating ADO-induced decreases in CF functions. For this purpose, CF were either treated pharmacologically or had the A2aR or A2bR levels modified through the use of recombinant adenovirus or siRNA. The assessment of mRNA expression in adult rat CF yielded evidence for A1R, A2bR, A2aR, and A3R. Endogenously or exogenously enhanced ADO significantly inhibits CF proliferation, collagen, and protein synthesis. A2R and A2aR agonists, although capable of inhibiting CF protein and collagen synthesis, were unable to define the contributions derived from A2aR or A2bR. Overexpression of A2bR in CF yielded significant decreases in basal levels of collagen and protein synthesis and correlated with increases in cAMP levels. However, at higher doses of ADO receptor agonists, significant increases in protein and collagen synthesis were observed. CF with underexpression of A2bR yielded increases in protein and collagen synthesis. In contrast, A2aR underexpression did not modify ADO-induced decreases in CF protein or collagen synthesis. In conclusion, results derived from the molecular manipulation of receptor levels indicate that A2bR are critically involved in ADO-mediated inhibition of CF functions.
Exercise hyperventilation, dyspnea sensation, and ergoreflex activation in lone atrial fibrillation
Authors: Guazzi Marco , Belletti Sebastiano , Tumminello Gabriele , Fiorentini Cesare , Guazzi Maurizio D.
Published: July 2004

Lone atrial fibrillation may be associated with daily life disability and exercise limitation. The extracardiac pathophysiology of these effects is poorly explored. In 35 subjects with lone atrial fibrillation (mean age 67 ± 7 yr), we investigated pulmonary function, symptom-limited cardiopulmonary exercise performance, muscle ergoreflex (handgrip exercise) contribution to ventilation, and brachial artery flow-mediated dilation (as a measure of endothelial function) before and after (average interval 20 ± 5 days) restoring sinus rhythm with external cardioversion. Respiratory volumes and lung diffusing capacity at rest were within normal limits during both atrial fibrillation and after restoring sinus rhythm. Cardioversion was associated with the following changes: a decrease of the slope of exercise ventilation vs. CO2 production (from 35 ± 5 to 29 ± 3; P < 0.01) and of dyspnea sensation (Borg score from 4 to 2) and an increase of peak oxygen uptake (V̇o2; from 16 ± 4 to 20 ± 5 ml·min−1·kg−1; P < 0.01), V̇o2 at anaerobic threshold (from 11 ± 2 to 13 ± 2 ml·min−1·kg−1; P < 0.05), and O2 pulse (from 8 ± 3 to 11 ± 3 ml/beat; P < 0.01). After cardioversion, the observed improvement in ventilatory efficiency was accompanied by a significant peak end-tidal CO2 increase (from 33 ± 2 to 37 ± 2 mmHg; P < 0.01) and no changes in dead space-to-tidal volume ratio (from 0.23 ± 0.03 to 0.23 ± 0.02; P = not significant). In addition, the ergoreflex contribution to ventilation was remarkably attenuated, and the brachial artery flow-mediated dilatation was significantly augmented (from 0.32 ± 0.07 to 0.42 ± 0.08 mm; P < 0.01). Ten patients had atrial fibrillation relapse and, compared with values after restoration of regular sinus rhythm, invariably showed worsening of endothelial function, exercise ventilatory efficiency, and muscle ergoreflex contribution to ventilation. In subjects with lone atrial fibrillation, an impairment in ventilatory efficiency appears to be involved in the pathophysiology of exercise limitation, and to be primarily related with a demodulated peripheral control of ventilation.
Intravenous administration of mesenchymal stem cells improves cardiac function in rats with acute myocardial infarction through angiogenesis and myogenesis
Authors: Nagaya Noritoshi , Fujii Takafumi , Iwase Takashi , Ohgushi Hajime , Itoh Takefumi , Uematsu Masaaki , Yamagishi Masakazu , Mori Hidezo , Kangawa Kenji , Kitamura Soichiro
Published: July 2004

Mesenchymal stem cells (MSCs) are pluripotent cells that differentiate into a variety of cells, including cardiomyocytes and endothelial cells. However, little information is available regarding the therapeutic potency of systemically delivered MSCs for myocardial infarction. Accordingly, we investigated whether intravenously transplanted MSCs induce angiogenesis and myogenesis and improve cardiac function in rats with acute myocardial infarction. MSCs were isolated from bone marrow aspirates of isogenic adult rats and expanded ex vivo. At 3 h after coronary ligation, 5 × 106 MSCs (MSC group, n = 12) or vehicle (control group, n = 12) was intravenously administered to Lewis rats. Transplanted MSCs were preferentially attracted to the infarcted, but not the noninfarcted, myocardium. The engrafted MSCs were positive for cardiac markers: desmin, cardiac troponin T, and connexin43. On the other hand, some of the transplanted MSCs were positive for von Willebrand factor and formed vascular structures. Capillary density was markedly increased after MSC transplantation. Cardiac infarct size was significantly smaller in the MSC than in the control group (24 ± 2 vs. 33 ± 2%, P < 0.05). MSC transplantation decreased left ventricular end-diastolic pressure and increased left ventricular maximum dP/d t (both P < 0.05 vs. control). These results suggest that intravenous administration of MSCs improves cardiac function after acute myocardial infarction through enhancement of angiogenesis and myogenesis in the ischemic myocardium.
Overexpression of human heme oxygenase-1 attenuates endothelial cell sloughing in experimental diabetes
Authors: Abraham Nader G. , Rezzani Rita , Rodella Luigi , Kruger Adam , Taller Derek , Li Volti Giovanni , Goodman Alvin I. , Kappas Attallah
Published: July 2004

Heme oxygenase (HO)-1 represents a key defense mechanism against oxidative injury. Hyperglycemia produces oxidative stress and various perturbations of cell physiology. The effect of streptozotocin (STZ)-induced diabetes on aortic HO activity, heme content, the number of circulating endothelial cells, and urinary 8-epi-isoprostane PGF2α(8-Epi) levels in control rats and rats overexpressing or underexpressing HO-1 was measured. HO activity was decreased in hyperglycemic rats. Hyperglycemia increased urinary 8-Epi, and this increase was augmented in rats underexpressing HO-1 and diminished in rats overexpressing HO-1. The number of detached endothelial cells and O2−formation increased in diabetic rats and in hyperglycemic animals underexpressing HO-1 and decreased in diabetic animals overexpressing HO-1 compared with controls. These data demonstrate that HO-1 gene transfer in hyperglycemic rats brings about a reduction in O2−production and a decrease in endothelial cell sloughing. Upregulation of HO-1 decreases oxidant production and endothelial cell damage and shedding and may attenuate vascular complications in diabetes.
Acclimatization to neurological decompression sickness in rabbits
Authors: Su Chien-Ling , Wu Chin-Pyng , Chen Shao-Yuan , Kang Bor-Hwang , Huang Kun-Lun , Lin Yu-Chong
Published: July 2004

Diving acclimatization refers to a reduced susceptibility to acute decompression sickness (DCS) in individuals undergoing repeated compression-decompression cycles. We demonstrated in a previous study that the mechanism responsible for this acclimatization is similar to that of stress preconditioning. In this study, we investigated the protective effect of prior DCS preconditioning on the severity of neurological DCS in subsequent exposure to high pressure in rabbits. We exposed the rabbits ( n = 10) to a pressure cycle of 6 absolute atmospheres (ATA) for 90 min, which induced signs of neurological DCS in 60% of the animals. Twenty-four hours after the pressure cycle, rabbits with DCS expressed more heat-shock protein 70 (HSP70) in the lungs, liver, and heart than rabbits without signs of disease or those in the control group ( n = 6). In another group of rabbits ( n = 24), 50% of animals presented signs of neurological DCS after exposure to high pressure, with a neurological score of 46.5 (SD 19.5). A course of hyperbaric oxygen therapy alleviated the signs of neurological DCS and ensured the animals' survival for 24 h. Experiencing another pressure cycle of 6 ATA for 90 min, 50% of 12 rabbits with prior DCS preconditioning developed signs of DCS, with a neurological score of 16.3 (SD 28.3), significantly lower than that before hyperbaric oxygen therapy ( P = 0.002). In summary, our results show that the occurrence of DCS in rabbits after rapid decompression is associated with increased expression of a stress protein, indicating that the stress response is induced by DCS. This phenomenon was defined as “DCS preconditioning.” DCS preconditioning attenuated the severity of neurological DCS caused by subsequent exposure to high pressure. These results suggest that bubble formation in tissues activates the stress response and stress preconditioning attenuates tissue injury on subsequent DCS stress, which may be the mechanism responsible for diving acclimatization.
System β and System A amino acid transporters in the feline endotheliochorial placenta
Authors: Champion E. E. , Mann S. J. , Glazier J. D. , Jones C. J. P. , Rawlings J. M. , Sibley C. P. , Greenwood S. L.
Published: July 2004

There is no knowledge of the transport mechanisms by which solutes cross the cat placenta or any other endotheliochorial placenta. Here, we investigated whether the amino acid transport systems β and A are present in the cat placenta using a placental fragment uptake technique. Data were compared with studies in the human placenta, in which the presence of these two transport systems has been well established. A time course of [3H]taurine (substrate for system β) and [14C]MeAIB (nonmetabolizable substrate for system A) uptake was determined in the term cat and human placental fragments in the presence and absence (choline substituted) of Na+, and further studies were carried out over 15 min. Taurine uptake into both cat and human placenta fragments was found to be Na+ and Cl− dependent, and Na+-dependent taurine uptake was blocked by excess β-alanine. MeAIB uptake was found to be Na+ dependent, and Na+-dependent MeAIB uptake was blocked by excess MeAIB or glycine. Western blotting and immunohistochemistry performed on cat and human placenta showed expression of TAUT and ATA2 (SNAT2), proteins associated with system β and system A activity, respectively. This study therefore provides the first evidence of the presence of amino acid transport systems β and A in the cat placenta.
Effect of power, pedal rate, and force on average muscle fiber conduction velocity during cycling
Authors: Farina Dario , Macaluso Andrea , Ferguson Richard A. , De Vito Giuseppe
Published: July 2004

Muscle fiber conduction velocity (MFCV) provides indications on motor unit recruitment strategies due to the relation between conduction velocity and fiber diameter. The aim of this study was to investigate MFCV of thigh muscles during cycling at varying power outputs, pedal rates, and external forces. Twelve healthy male participants aged between 19 and 30 yr cycled on an electronically braked ergometer at 45, 60, 90, and 120 rpm. For each pedal rate, subjects performed two exercise intensities, one at an external power output corresponding to the previously determined lactate threshold (100% LT) and the other at half of this power output (50% LT). Surface electromyogram signals were detected during cycling from vastus lateralis and medialis muscles with linear adhesive arrays of eight electrodes. In both muscles, MFCV was higher at 100% LT compared with 50% LT for all average pedal rates except 120 rpm (mean ± SE, 4.98 ± 0.19 vs. 4.49 ± 0.18 m/s; P < 0.001). In all conditions, MFVC increased with increasing instantaneous knee angular speed (from 4.14 ± 0.16 to 5.08 ± 0.13 m/s in the range of instantaneous angular speeds investigated; P < 0.001). When MFCV was compared at the same external force production (i.e., 90 rpm/100% LT vs. 45 rpm/50% LT, and 120 rpm/100% LT vs. 60 rpm/50% LT), MFCV was higher at the faster pedal rate (5.02 ± 0.17 vs. 4.64 ± 0.12 m/s, and 4.92 ± 0.19 vs. 4.49 ± 0.11 m/s, respectively; P < 0.05) due to the increase in inertial power required to accelerate the limbs. It was concluded that, during repetitive dynamic movements, MFCV increases with the external force developed, instantaneous knee angular speed, and average pedal rate, indicating progressive recruitment of large, high conduction velocity motor units with increasing muscle force.
Enhancement of Quality of Life with Adjustment of Dry Weight by Echocardiographic Measurement of Inferior Vena cava Diameter in Patients Undergoing Chronic Hemodialysis
Authors: Chang Shih-Tai , Chen Chein-Lung , Chen Chien-Chung , Lin Fun-Chung , Wu Delon
Published: July 2004

Background/Aims: Ideal dry weight (DW) can serve as a marker of good quality of life (QOL) in patients receiving chronic hemodialysis. The size of the inferior vena cava (IVC) reflects the intravascular fluid status, and the diameter of IVC correlates indirectly with DW in these patients. Adjusting DW using echocardiographic measurement of the diameter of the IVC thus may be useful in maintenance of a better QOL in patients receiving chronic hemodialysis. Methods: This study included 119 patients with ages ranging between 27 and 90 years (mean ± standard deviation of 58.3 ± 12.8). All of the patients received the IVC diameter (IVCD) measurement by echocardiography every 2 months for 1 year. The study group included 68 patients in whom the DW were adjusted by echocardiographic measurement of the IVCD, while the control group included 51 patients in whom the DW was adjusted by the conventional method. QOL was evaluated using the short form 36 questionnaire (SF-36) at the beginning and at the end of the study. Besides, the Kt/Vurea value, a parameter of total urea clearance, was measured at the beginning and at the end of the study in patients of both groups. Results: The scores of physical functioning, physical role functioning, general health and physical component summary showed a prominent improvement in the study group but not in the control group. The impact of periodic echocardiographic evaluation also demonstrated a significant change in the scores of physical functioning, physical role functioning and physical component summary in the study group. Furthermore, the Kt/Vurea value, a parameter of total urea clearance, also increased significantly in the study group. Conclusion: Ideal DW is better adjusted by periodic echocardiographic measurement of the IVCD in patients undergoing chronic hemodialysis. Maintenance of a better DW leads to improve hemodialysis quality and QOL in these patients.
Role of Isoprenoids in Cytoskeleton Integrity and Albumin Endocytosis by Opossum Kidney Cells
Authors: McTaggart Steven J. , Eitle Eveline , Harris Peter J. , Jones Colin L.
Published: July 2004

Background: The actin cytoskeleton has been increasingly implicated in endocytic events that are involved in the reabsorption of filtered protein by the proximal tubule. Isoprenylated small G proteins have emerged as key regulators of the actin cytoskeleton. This study examines the role of isoprenoid intermediates in organization of the cytoskeleton, and the effect of modification of the cytoskeleton on albumin endocytosis. Methods: The effect of lovastatin on cytoskeleton morphology of opossum kidney cells (OK cells) was determined by staining with fluorescent isothiocyanate (FITC)-phalloidin followed by examination using confocal microscopy. Quantitative effects on albumin binding and uptake were determined using a well-established method. Results: Inhibition of isoprenoid synthesis by lovastatin led to morphological disruption of the cytoskeleton with a concentration-dependent decrease in albumin uptake into OK cells. Addition of mevalonate, but not cholesterol, ameliorated the effects of lovastatin on the cytoskeleton and albumin uptake. Selective inhibition of isoprenoid intermediates with a farnesyltransferase inhibitor suggests that geranylgeranylated proteins mediate cytoskeleton organization. Conclusion: These results confirm the importance of cytoskeleton integrity in albumin endocytosis in renal proximal tubules. While the present data suggest that synthesis of isoprenoids via the mevalonate pathway is a critical step in maintenance of the cytoskeleton, the role of individual small G proteins in control of the cytoskeleton and other endocytic events is yet to be defined.
Reliability of T7-Based mRNA Linear Amplification Validated by Gene Expression Analysis of Human Kidney Cells Using cDNA Microarrays
Authors: Rudnicki Michael , Eder Susanne , Schratzberger Gabriele , Mayer Bernd , Meyer Timothy W. , Tonko Martin , Mayer Gert
Published: July 2004

Genome wide gene expression analysis by cDNA microarrays is often limited by minute amounts of starting RNA. We therefore tested an optimized linear RNA amplification protocol using the RiboAmp® amplification kit in the setting of cDNA microarrays. We isolated mRNA from a human kidney cell line (HK-2; ATCC) and from Universal Human Reference RNA (STR; Stratagene). After performing one and two rounds of linear RNA amplification, respectively, the amplified RNAs were co-hybridized to cDNA microarrays. Linearity and reproducibility of the individual experiments were then assessed by calculating the Pearson correlation. The intra-amplification consistency showed a correlation of 0.968 for the first round, 0.907 for the second round and 0.912 for two successive rounds of amplification. If the first round was compared to unamplified material, r was 0.925. The second round amplification yielded a correlation of 0.897 if compared to unamplified mRNA. Two rounds of amplification starting from 200 pg of mRNA compared to unamplified material resulted in a correlation of 0.868. These results indicate that linear amplification using RiboAmp® kit yields amplified RNA with a high degree of linearity and reproducibility.
Expression of Osteopontin in Cisplatin-Induced Tubular Injury
Authors: Iguchi Seitaro , Nishi Shinichi , Ikegame Mika , Hoshi Kazuto , Yoshizawa Tatsuya , Kawashima Hiroyuki , Arakawa Masaaki , Ozawa Hidehiro , Gejyo Fumitake
Published: July 2004

Osteopontin (OPN) is considered as a key protein in cell regeneration. OPN is thought to have many functions in cell-cell binding and cell-matrix binding via OPN receptors in various organs. But there is little information on the precise role of OPN. To clarify the functional role of OPN in tubular injury, we performed in situ hybridization and immunohistochemical analysis of the expression of OPN in a renal cortical necrosis model induced by cisplatin from the acute injury to late recovery phases. In the acute injury phase, both mRNA and protein of OPN were markedly induced in damaged tubular lumens with cell debris. In the late recovery phase, on the other hand, OPN protein and mRNA were observed in dilated and flattened tubular epithelial cells showing a regenerative appearance. Most of these cells were also immunostained with CD44, a receptor of OPN. PCNA staining was also co-localized with these expressions. In light of the CD44 function regulating cell proliferation, these findings suggest that OPN may contribute to regeneration of tubular epithelial cells during the acute to late recovery phases of cortical tubular damage induced by cisplatin.
CT in the Differentiation of Pancreatic Neoplasms – Progress Report
Authors: Gritzmann Norbert , Macheiner Peter , Hollerweger Alois , Hübner Erich
Published: July 2004

Today, computed tomography (CT) is the most commonly used imaging method in the assessment of pancreatic tumors. The sensitivity of CT in detection of pancreatic tumors is more than 90% when direct and indirect signs are used for diagnosis. However, the potential to differentiate exocrine (non-endocrine) tumors of the pancreas is limited. CT is used in these lesions to perform an adequate staging, especially for surgical purposes. The operative resectability, primarily in regard to vessels, lymph node metastasis and hepatic metastasis, has to be assessed. Keeping in mind the limitations of this macromorphological imaging procedure, CT has the best reproducibility and overall accuracy of all imaging methods. Using multislice CT it is possible to perform non-axial reconstructions with high resolution. In functional endocrine tumors, multislice spiral CT will enhance the diagnostic capabilities, since the whole organ can be examined in thin slices, with high resolution during the rather short arterial phase of the contrast medium. Since some endocrine tumors are hypovascular, a scan during the portovenous phase is recommended too. The diagnosis of benign pancreatic tumors, like serous cystadenoma and pancreatic lipomas, is addressed. The most important pseudotumors of the pancreas are discussed.
ERCP and MRCP in the Differentiation of Pancreatic Tumors
Authors: Hartmann Dirk , Schilling Dieter , Bassler Boris , Adamek Henning E. , Layer Günter , Riemann Jürgen F.
Published: July 2004

The introduction of endoscopic retrograde cholangiopancreatography (ERCP) in the early 1970s provided gastroenterologists with a number of diagnostic as well as therapeutic possibilities for examining biliopancreatic systems. In the meantime, magnetic resonance cholangiopancreatography presents a non-invasive alternative to diagnostic ECRP providing the advantage of a lower rate of possible complications. This article addresses the two methods presently available for differentiating pancreatic tumors. The objective of this article is to describe the advantages and disadvantages as well as the possibilities inherent in both methods.
Echo-Enhanced Sonography – An Increasingly Used Procedure for the Differentiation of Pancreatic Tumors
Authors: Rickes Steffen , Malfertheiner Peter
Published: July 2004

Echo-enhanced sonography is increasingly being used for differential diagnosis of pancreatic tumors. Ductal carcinomas are often hypovascularized compared with the surrounding tissue. On the other hand, neuroendocrine tumors are hypervascularized lesions. Tumors associated with pancreatitis have a different vascularization pattern depending on inflammation and necrosis. Cystadenomas frequently show many vessels along the fibrotic strands. Pancreatic tumors have a different vascularization pattern in echo-enhanced sonography. These characteristics can be used for differential diagnosis. However, histology is the standard of reference.
CT Scan and MRI in the Differentiation of Liver Tumors
Authors: Hori Masatoshi , Murakami Takamichi , Kim Tonsok , Tomoda Kaname , Nakamura Hironobu
Published: July 2004

Computed tomography (CT) and magnetic resonance imaging (MRI) are useful for detection and characterization of liver tumors, and widely used in clinical practice. By using dynamic CT and MRI with extracellular contrast material or MRI with liver-specific contrast material, we can investigate the morphological, hemodynamical and functional nature of focal hepatic lesions. Tumors often show characteristic findings on CT and MRI. Thus, we can correctly establish a diagnosis of liver tumors based on those findings. In this article, we describe the role of CT scan and MRI in the differentiation of liver tumors as well as presenting some typical CT and MR images.
Imaging of Inflammatory Bowel Disease: CT and MR
Authors: Zalis Michael , Singh Ajay K.
Published: July 2004

Cross-sectional imaging has come to play a central role in the imaging of the abdomen. Concurrent to this, the role of CT and MRI in the imaging of inflammatory bowel disease has also increased in importance. These modalities offer numerous advantages over more traditonal methods of radiologic diagnosis, and provide essential information not only for initial diagnosis, but for management, follow-up and detection of potential complications. On the horizon are several derivative techniques involving CT and MRI, potentially in combination with PET imaging; these may further improve the specificity and sensitivity of imaging modalities for diagnosis of inflammatory bowel disease.
Doppler Sonography in the Diagnosis of Inflammatory Bowel Disease
Authors: Di Sabatino Antonio , Armellini Elia , Corazza Gino Roberto
Published: July 2004

Over the past few years, thanks to its ability to reveal neovascularization and inflammatory hyperemia, Doppler sonography has proved to be a valuable method for the assessment of disease activity in inflammatory bowel disease. Hypervascularization has been detected by Doppler imaging both in splanchnic vessels, in terms of flow volume and velocity, or resistance and pulsatility index on spectral analysis, and in small vessels of the affected bowel wall in terms of vessel density. In particular, power Doppler has been shown to be a highly sensitive method for evaluating the presence of flow in vessels that are poorly imaged by conventional color Doppler, and in detecting internal fistulas complicating Crohn’s disease. Recently, the use of ultrasound contrast agents, such as Levovist, has been shown to improve the image quality of color Doppler by increasing the backscattered echoes from the desired regions, thus making it possible to better monitor the response to treatment and discriminate between active inflammatory and fibrotic bowel wall thickness in Crohn’s disease. Additionally, Levovist-enhanced power Doppler sonography has proved to be highly sensitive and specific in the detection of inflammatory abdominal masses associated with Crohn’s disease. In clinical practice, used in combination with second harmonic imaging and new generations of stable contrast agents, Doppler sonography appears to be a non-invasive and effective diagnostic tool in the diagnosis and follow-up of Crohn’s disease and ulcerative colitis.
Evaluation of Criteria for the Activity of Crohn’s Disease by Power Doppler Sonography
Authors: Neye Holger , Voderholzer Winfried , Rickes Steffen , Weber Jutta , Wermke Wolfram , Lochs Herbert
Published: July 2004

Background/Aim: In recent years, power Doppler sonography has been proposed as a method to assess disease activity in patients with Crohn’s disease. The aim of this prospective study was to evaluate diagnostic criteria for power Doppler sonography by blinded comparison with ileocolonoscopy. Methods: Twenty-two patients with confirmed Crohn’s disease were prospectively investigated with B-mode and power Doppler sonography (HDI 5000, Philips Ultrasound) as well as ileocolonoscopy. Sonography was performed within 3 days before endoscopy. All procedures were performed by experienced examiners who were blinded to the clinical data and other results. Defined ultrasound parameters (bowel wall thickness, vascularization pattern) were used to determine a sonographic score of the activity. The degree of activity was scored from 1 (none) to 4 (high) by both ultrasound and ileocolonoscopy (pattern, extent of typical lesions). For each patient all segments of the colon and the terminal ileum were evaluated by both ultrasound and endoscopy. The weighted ĸ test was used (StatXact software) for statistical analysis. Results: In total, 126 bowel segments were evaluated by both ultrasound and endoscopy. The study showed a high concordance of power Doppler sonography and ileocolonoscopy (weighted ĸ by region: sigmoid colon: 0.81; transverse colon: 0.78; ascending colon: 0.75; cecum: 0.84; terminal ileum: 0.82). Highest concordance was found in the descending colon (weighted ĸ: 0.91; 95% CI: 0.83–0.98). Conclusions: Combination of B-mode and power Doppler sonography has a high accuracy in the determination of disease activity in Crohn’s disease when compared to ileocolonoscopy. The diagnostic criteria established in this study can be useful for the evaluation of inflammatory bowel diseases by ultrasound.
Fibromyalgia: A Stress Disorder?
Authors: van Houdenhove Boudewijn , Egle Ulrich T.
Published: July 2004

Fibromyalgia (FM) is a controversial syndrome, characterised by persistent widespread pain, abnormal pain sensitivity and additional symptoms such as fatigue and sleep disturbance. The syndrome largely overlaps with other functional somatic disorders, particularly chronic fatigue syndrome (CFS). Although the exact aetiology and pathogenesis of FM are still unknown, it has been suggested that stress may play a key role in the syndrome. This article first reviews the function of the stress response system, placing special emphasis on the relationships between adverse life experiences, stress regulation and pain-processing mechanisms, and summarising the evidence for a possible aetiopathogenetic role of stress in FM. Finally, an integrative biopsychosocial model that conceptualises FM as a stress disorder is proposed, and the clinical and research implications of the model are discussed.
Psychosocial Intervention for Women with Primary, Non-Metastatic Breast Cancer: A Comparison between Participants and Non-Participants
Authors: Vos Petra J. , Garssen Bert , Visser Adriaan P. , Duivenvoorden Hugo J. , de Haes Hanneke C.J.M.
Published: July 2004

Background: Despite improvements in the medical treatment of breast cancer, resulting in better prognoses, women diagnosed with the illness often experience psychosocial problems. As a result, many psychosocial intervention programs have been developed, usually with positive results. The aim of this study was to examine the effects of two 12-week psychosocial intervention programs for women with a primary, non-metastatic breast cancer diagnosis in comparison to women who were on a waiting list for these interventions for 3 months. Methods: Sixty-nine women with primary, non-metastatic breast cancer, but otherwise without psychosocial problems, were randomized to a group of patients treated with the intervention program (group psychotherapy or social support group) or a control group (on a waiting list). Differences between both groups in psychosocial adjustment, social support and coping at the short-term follow-up were described in this study. Results: Women who participated in the group intervention programs did not differ from women in the control group regarding psychosocial adjustment at the end of the study. Women who participated in the social support groups reported to receive more social support from others not very close to them. They also used more palliative coping than women from the psychotherapy group. Conclusions: Apparently, women who are being diagnosed with breast cancer, but otherwise have no psychosocial adjustment problems following the diagnosis, do not especially benefit from a short-term intervention program compared to women in the control group.
Predicting Long-Term Outcome in Group Treatment of Atopic Dermatitis
Authors: Stangier Ulrich , Ehlers Anke , Gieler Uwe
Published: July 2004

Background: Psychological group treatments are effective adjuncts to dermatological treatments in improving dermatological symptoms and quality of life. However, no data are available on variables that may predict which patients benefit from such group treatments. Methods: On the basis of data from the Marburg group treatment study, we explored which variables are associated with successful treatment. Treatment outcome was defined by a marked reduction of dermatological symptoms at 1-year follow-up. Results: Regardless of the treatment condition, a high pretreatment level of scratching, a low serum IgE level, low scores on the internal Health Locus of Control Scale and a high frequency of coping-related cognitions regarding itching predicted good outcome at 1 year. Logistic regression analyses indicated that the predictive power of locus of control and itch-related cognitions differed between different treatment conditions. Conclusion: In patients with atopic dermatitis, indication for psychological treatment may be based on the assessment of psychological target problems including excessive scratching and dysfunctional cognitions.
Impact of a Psychoeducational Family Intervention on Caregivers of Stabilized Bipolar Patients
Authors: Reinares M. , Vieta E. , Colom F. , Martínez-Arán A. , Torrent C. , Comes M. , Goikolea J.M. , Benabarre A. , Sánchez-Moreno J.
Published: July 2004

Background: Environmental stress has an important role in the course of bipolar disorder. Some findings have shown that family beliefs about the illness could predict family burden, and this burden could influence the outcome of bipolar disorder. To the best of our knowledge, there is scant information about the effects of family intervention on the caregiver’s burden in bipolar disorder. The aim of this study was to assess the effects of psychoeducational family intervention on bipolar patients’ caregivers, including the assessment of the caregiver’s burden. Methods: 45 medicated euthymic bipolar outpatients were randomized into an experimental and a control group. Relatives of patients from the experimental group received 12 psychoeducational, 90-min sessions about bipolar disorder and coping skills. The caregivers’ knowledge of bipolar disorder, the relationship subscales of the Family Environment Scale, and the family burden subscales from an adapted version of the Social Behavior Assessment Schedule were assessed for both caregiver groups before and after the intervention. Results: Psychoeducated caregivers significantly improved their knowledge of bipolar disorder and reduced both the subjective burden and the caregiver’s belief about the link between the objective burden and the patient. No significant differences were found in the objective burden nor in the family relationship subscales. Conclusions: These preliminary results suggest that psychoeducational intervention on caregivers of bipolar patients may improve the caregiver’s knowledge of the illness, reduce their distress or subjective burden and alter their beliefs about the link between the disruptions in their life and the patient’s illness.
QT Interval and QT Dispersion in Eating Disorders
Authors: Takimoto Yoshiyuki , Yoshiuchi Kazuhiro , Kumano Hiroaki , Yamanaka Gaku , Sasaki Tadashi , Suematsu Hiroyuki , Nagakawa Yuzo , Kuboki Tomifusa
Published: July 2004

Background: Eating disorders are thought to be risk factors for cardiac sudden death secondary to arrhythmia. Results in previous studies on QT interval and QT dispersion, markers of fatal arrhythmia, have been inconsistent. Methods: We prospectively examined 179 female eating disorder patients, being over 18 years old and diagnosed according to the DSM-IV criteria between January 1995 and December 2002, and 52 healthy women. Patients with abnormal plasma electrolytes or taking medications that might influence the electrocardiogram (ECG) were excluded from the study. QT intervals were corrected for heart rate using Bazett’s formula and the nomogram method, which is more reliable at extremely low heart rates than Bazett’s formula. QT dispersion was measured as the difference between the longest and shortest QT intervals. QT intervals and QT dispersion in each patient group were compared with those in the control group. Results: The 164 eligible patients consisted of 43 patients with anorexia nervosa restricting type, 35 with anorexia nervosa binge eating/purging type, 63 with bulimia nervosa purging type, and 23 with bulimia nervosa nonpurging type. There was no significant difference in age between eating disorder patients and controls. QT interval and QT dispersion were significantly longer in all eating disorder subtypes than in the control group. QT interval and QT dispersion were significantly correlated with the rate of body weight loss in bulimia nervosa. Conclusions: QT interval and QT dispersion were prolonged in both anorexia nervosa and bulimia nervosa. Examination of ECG in eating disorder patients without extremely low body weight also appears to be clinically important.
Can We Continue Research in Splenectomized Dogs? Mycoplasma haemocanis: Old Problem – New Insight
Authors: Kemming G. , Messick J.B. , Mueller W. , Enders G. , Meisner F. , Muenzing S. , Kisch-Wedel H. , Schropp A. , Wojtczyk C. , Packert K. , Messmer K. , Thein E.
Published: July 2004

We report the appearance of a Mycoplasma haemocanis infection in laboratory dogs, which has been reported previously, yet, never before in Europe. Outbreak of the disease was triggered by a splenectomy intended to prepare the dogs for a hemorrhagic shock study. The clinical course of the dogs was dramatic including anorexia and hemolytic anemia. Treatment included allogeneic transfusion, prednisone, and oxytetracycline. Systematic follow-up (n = 12, blood smears, antibody testing and specific polymerase chain reaction) gives clear evidence that persistent eradication of M. haemocanis is unlikely. We, therefore, had to abandon the intended shock study. In the absence of effective surveillance and screening for M. haemocanis, the question arises whether it is prudent to continue shock research in splenectomized dogs.
Skin Preservation at a Supraphysiologic Temperature and Induction of Epithelial Cysts by Subcutaneous Grafting: Attempts to Simplify Evaluation of Storage Media and of Graft Viability
Authors: Macionis V.
Published: July 2004

This pilot study used a new experimental rat model designed to explore whether in-depth investigation of the following two questions would be reasonable: (1) Can skin storage media be faster evaluated by storing skin at a supraphysiologic temperature, and (2) can evaluation of skin graft viability be facilitated by subcutaneous grafting leading to production of epithelial cysts from the viable portions of the grafts? The experiment involved skin storage at 47.3°C in saline and in 10% Dextran 40 solution for periods ranging from 0 to 18 min, followed by subcutaneous grafting. The surface area of the resultant epithelial cysts and the cyst-to-graft ratio inversely correlated with storage time, which is in accordance with a well-established analogous relationship involving the rate of graft ‘take’. The skin tended to remain viable longer in Dextran 40 solution, which is consistent with previous studies of low temperature storage demonstrating superiority of high-molecular-weight solutions. The results warrant further investigation of the above issues.
E-PASS (The Estimation of Physiologic Ability and Surgical Stress) Scoring System Helps the Prediction of Postoperative Morbidity and Mortality in Thoracic Surgery
Authors: Yamashita S. , Haga Y. , Nemoto E. , Nagai S. , Ohta M.
Published: July 2004

Objective: When a new scoring system, ‘E-PASS’, standing for the Estimation of Physiologic Ability and Surgical Stress that predicts the postoperative surgical risk by quantification of the patient’s reserve and surgical stress applied to a population of general thoracic surgery patients, it should be investigated if this system could help us or not. Methods: The comprehensive risk score (CRS) of the E-PASS and the clinical course were evaluated retrospectively in 282 consecutive patients with primary lung cancer (group A), and in 458 patients who underwent elective thoracic operations (group B). Results: The morbidity and mortality rates in both group A and group B increased as the CRS increased. The CRS correlated significantly with the morbidity score, length of stay and cost of hospitalization. Conclusions: E-PASS scoring system may be useful in surgical decision-making and evaluating quality of care in patients who are tolerable for lung resection.
Linkage of M5 Muscarinic and α7-Nicotinic Receptor Genes on 15q13 to Schizophrenia
Authors: De Luca Vincenzo , Wang Haoran , Squassina Alessio , Wong Greg W.H. , Yeomans John , Kennedy James L.
Published: July 2004

Most antipsychotic drugs act on the forebrain by blocking dopamine receptors. In rodents, the M5 muscarinic receptor (CHRM5) is important for prolonged dopamine release. We typed polymorphisms in CHRM5 and α7-nicotinic receptor (CHRNA7) genes on 15q13 in 82 Canadian families having at least 1 schizophrenic patient. Using the Family-Based Association Test, we performed haplotype analysis of the 2 loci and found biased transmission in schizophrenia (z = –2.651, p = 0.008). In the families tested, the 2 cholinergic genes interacted to affect schizophrenia in combination, while neither was sufficiently alone to confer susceptibility. Our present study provided the first line of direct evidence suggesting that the CHRM5 gene combined with the CHRNA7 gene may be linked to schizophrenia.
Sleep in Young Adults with Asperger Syndrome
Authors: Tani Pekka , Lindberg Nina , Nieminen-von Wendt Taina , von Wendt Lennart , Virkkala Jussi , Appelberg Björn , Porkka-Heiskanen Tarja
Published: July 2004

Asperger syndrome (AS) is a neurodevelopmental disorder belonging to autism spectrum disorders. Both children and adults with AS have subjective impairment in the initiation and continuity of sleep, and studies using objective assessment are sparse. Twenty young AS adults with frequent complaints of low sleep quality were compared to 10 age-, gender- and education-matched controls without sleep complaints using polysomnography and spectral power analysis of slow-wave sleep. AS subjects displayed a similar polysomnographic profile as compared with controls. In spectral power analysis, a statistically nonsignificant trend towards decreased relative delta power and increased theta power in slow-wave sleep was found in the AS group. It seems that nonorganic insomnia, due to anxiety inherent in AS, is responsible for the low sleep quality in these subjects.