bluuebunny/crossref_metadata_2025 huggingface dataset:
A rat model reproducing key pathological responses of alcoholic chronic pancreatitis
Authors: Gukovsky Ilya , Lugea Aurelia , Shahsahebi Mohammad , Cheng Jason H. , Hong Peggy P. , Jung Yoon J. , Deng Quing-gao , French Barbara A. , Lungo William , French Samuel W. , Tsukamoto Hidekazu , Pandol. Stephen J.
Published: September 2007

Although alcohol abuse is the major cause of chronic pancreatitis, the pathogenesis of alcoholic chronic pancreatitis (ACP) remains obscure. A critical obstacle to understanding the mechanism of ACP is lack of animal models. Our objective was to develop one such model. Rats were pair-fed for 8 wk ethanol or control Lieber-DeCarli liquid diet. For the last 2 wk, they received cyclosporin A (CsA; 20 mg/kg once daily) or vehicle. After 1 wk on CsA, one episode of acute pancreatitis was induced by four 20 μg/kg injections of cerulein (Cer); controls received saline. Pancreas was analyzed 1 wk after the acute pancreatitis. CsA or Cer treatments alone did not result in pancreatic injury in either control (C)- or ethanol (E)-fed rats. We found, however, that alcohol dramatically aggravated pathological effect of the combined CsA+Cer treatment on pancreas, resulting in massive loss of acinar cells, persistent inflammatory infiltration, and fibrosis. Macrophages were prominent in the inflammatory infiltrate. Compared with control-fed C+CsA+Cer rats, their ethanol-fed E+CsA+Cer counterparts showed marked increases in pancreatic NF-κB activation and cytokine/chemokine mRNA expression, collagen and fibronectin, the expression and activities of matrix metalloproteinase-2 and -9, and activation of pancreatic stellate cells. Thus we have developed a model of alcohol-mediated postacute pancreatitis that reproduces three key responses of human ACP: loss of parenchyma, sustained inflammation, and fibrosis. The results indicate that alcohol impairs recovery from acute pancreatitis, suggesting a mechanism by which alcohol sensitizes pancreas to chronic injury.
A role of Wnt/β-catenin signals in hepatic fate specification of human umbilical cord blood-derived mesenchymal stem cells
Authors: Yoshida Yoko , Shimomura Takashi , Sakabe Tomohiko , Ishii Kyoko , Gonda Kazue , Matsuoka Saori , Watanabe Yumi , Takubo Kazuko , Tsuchiya Hiroyuki , Hoshikawa Yoshiko , Kurimasa Akihiro , Hisatome Ichiro , Uyama Taro , Terai Masanori , Umezawa Akihiro , Shiota Goshi
Published: September 2007

Human umbilical cord blood-derived mesenchymal stem cells (UCBMSCs) are expected to be an excellent source of cells for transplantation. In addition, the stem cell plasticity of human UCBMSCs, which can transdifferentiate into hepatocytes, has been reported. However, the mechanisms involved remain to be clarified. To identify the genes and/or signals that are important in specifying the hepatic fate of human UCBMSCs, we analyzed gene expression profiles during the hepatic differentiation of UCBMSCs with human telomerase reverse transcriptase, UCBMSCs immortalized by infection with a retrovirus carrying telomerase reverse transcriptase, but whose differentiation potential remains unchanged. Efficient differentiation was induced by 5-azacytidine (5-aza)/hepatocyte growth factor (HGF)/oncostatin M (OSM)/fibroblast growth factor 2 (FGF2) treatment in terms of function as well as protein expression: 2.5-fold increase in albumin, 4-fold increase in CCAAT enhancer-binding protein α, 1.5-fold increase in cytochrome p450 1A1/2, and 8-fold increase in periodic acid-Schiff staining. Consequently, we found that the expression of Wnt/β-catenin-related genes downregulated, and the translocation of β-catenin was observed along the cell membrane and in the cytoplasm, although some β-catenin was still in the nucleus. Downregulation of Wnt/β-catenin signals in the cells by Fz8-small interference RNA treatment, which was analyzed with a Tcf4 promoter-luciferase assay, resulted in similar hepatic differentiation to that observed with 5-azacytidine/HGF/OSM/FGF2. In addition, the subcellular distribution of β-catenin was similar to that of cells treated with 5-azacytidine/HGF/OSM/FGF2. In conclusion, the suppression of Wnt/β-catenin signaling induced the hepatic differentiation of UCBMSCs, suggesting that Wnt/β-catenin signals play an important role in the hepatic fate specification of human UCBMSCs.
Mechanisms of platelet and leukocyte recruitment in experimental colitis
Authors: Vowinkel Thorsten , Wood Katherine C. , Stokes Karen Y. , Russell Janice , Tailor Anitaben , Anthoni Christoph , Senninger Norbert , Krieglstein Christian F. , Granger D. Neil
Published: September 2007

Both leukocytes and platelets accumulate in the colonic microvasculature during experimental colitis, leading to microvascular dysfunction and tissue injury. The objective of this study was to determine whether the recruitment of leukocytes and platelets in inflamed colonic venules are codependent processes. The rolling and adherence of leukocytes and platelets in colonic venules of mice with dextran sodium sulfate (DSS)-induced colitis were monitored by intravital videomicroscopy. DSS elicited an increased recruitment of both rolling and adherent leukocytes and platelets. DSS-colitic mice rendered thrombocytopenic with anti-platelet serum exhibited profound reductions in leukocyte adhesion. Neutropenia, induced with anti-neutrophil serum, significantly reduced the adhesion of leukocytes and the accumulation of platelet-leukocyte aggregates while greatly enhancing the number of platelets that roll and adhere directly to venular endothelial cells. The enhanced platelet adhesion associated with neutropenia was mediated by platelet P-selectin interactions with endothelial cell P-selectin glycoprotein ligand (PSGL-1). DSS colitis was also associated with an increased expression of PSGL-1 in the colonic vasculature. These findings indicate that the recruitment of leukocytes and platelets in inflamed colonic venules are codependent processes.
Cannabidiol, a nonpsychoactive Cannabis constituent, protects against myocardial ischemic reperfusion injury
Authors: Durst Ronen , Danenberg Haim , Gallily Ruth , Mechoulam Raphael , Meir Keren , Grad Etty , Beeri Ronen , Pugatsch Thea , Tarsish Elizabet , Lotan Chaim
Published: September 2007

Cannabidiol (CBD) is a major, nonpsychoactive Cannabis constituent with anti-inflammatory activity mediated by enhancing adenosine signaling. Inasmuch as adenosine receptors are promising pharmaceutical targets for ischemic heart diseases, we tested the effect of CBD on ischemic rat hearts. For the in vivo studies, the left anterior descending coronary artery was transiently ligated for 30 min, and the rats were treated for 7 days with CBD (5 mg/kg ip) or vehicle. Cardiac function was studied by echocardiography. Infarcts were examined morphometrically and histologically. For ex vivo evaluation, CBD was administered 24 and 1 h before the animals were killed, and hearts were harvested for physiological measurements. In vivo studies showed preservation of shortening fraction in CBD-treated animals: from 48 ± 8 to 39 ± 8% and from 44 ± 5 to 32 ± 9% in CBD-treated and control rats, respectively ( n = 14, P < 0.05). Infarct size was reduced by 66% in CBD-treated animals, despite nearly identical areas at risk (9.6 ± 3.9 and 28.2 ± 7.0% in CBD and controls, respectively, P < 0.001) and granulation tissue proportion as assessed qualitatively. Infarcts in CBD-treated animals were associated with reduced myocardial inflammation and reduced IL-6 levels (254 ± 22 and 2,812 ± 500 pg/ml in CBD and control rats, respectively, P < 0.01). In isolated hearts, no significant difference in infarct size, left ventricular developed pressures during ischemia and reperfusion, or coronary flow could be detected between CBD-treated and control hearts. Our study shows that CBD induces a substantial in vivo cardioprotective effect from ischemia that is not observed ex vivo. Inasmuch as CBD has previously been administered to humans without causing side effects, it may represent a promising novel treatment for myocardial ischemia.
Evaluation of two cold thermoregulatory models for prediction of core temperature during exercise in cold water
Authors: Castellani John W. , O'Brien Catherine , Tikuisis Peter , Sils Ingrid V. , Xu Xiaojiang
Published: September 2007

Cold thermoregulatory models (CTM) have primarily been developed to predict core temperature (Tcore) responses during sedentary immersion. Few studies have examined their efficacy to predict Tcore during exercise cold exposure. The purpose of this study was to compare observed Tcore responses during exercise in cold water with the predicted Tcore from a three-cylinder (3-CTM) and a six-cylinder (6-CTM) model, adjusted to include heat production from exercise. A matrix of two metabolic rates (0.44 and 0.88 m/s walking), two water temperatures (10 and 15°C), and two immersion depths (chest and waist) were used to elicit different rates of Tcore changes. Root mean square deviation (RMSD) and nonparametric Bland-Altman tests were used to test for acceptable model predictions. Using the RMSD criterion, the 3-CTM did not fit the observed data in any trial, whereas the 6-CTM fit the data (RMSD less than standard deviation) in four of eight trials. In general, the 3-CTM predicted a rapid decline in core temperature followed by a plateau. For the 6-CTM, the predicted Tcore appeared relatively tight during the early part of immersion, but was much lower during the latter portions of immersion, accounting for the nonagreement between RMSD and SD values. The 6-CTM was rerun with no adjustment for exercise metabolism, and core temperature and heat loss predictions were tighter. In summary, this study demonstrated that both thermoregulatory models designed for sedentary cold exposure, currently, cannot be extended for use during partial immersion exercise in cold water. Algorithms need to be developed to better predict heat loss during exercise in cold water.
Role of adenosine in regulating the heterogeneity of skeletal muscle blood flow during exercise in humans
Authors: Heinonen Ilkka , Nesterov Sergey V. , Kemppainen Jukka , Nuutila Pirjo , Knuuti Juhani , Laitio Ruut , Kjaer Michael , Boushel Robert , Kalliokoski Kari K.
Published: September 2007

Evidence from both animal and human studies suggests that adenosine plays a role in the regulation of exercise hyperemia in skeletal muscle. We tested whether adenosine also plays a role in the regulation of blood flow (BF) distribution and heterogeneity among and within quadriceps femoris (QF) muscles during exercise, measured using positron emission tomography. In six healthy young women, BF was measured at rest and then during three incremental low and moderate intermittent isometric one-legged knee-extension exercise intensities without and with theophylline-induced nonselective adenosine receptor blockade. BF heterogeneity within muscles was calculated from 16-mm3voxels in BF images and heterogeneity among the muscles from the mean values of the four QF compartments. Mean BF in the whole QF and its four parts increased, and heterogeneity decreased with workload both without and with theophylline ( P < 0.001). Adenosine receptor blockade did not have any effect on mean bulk BF or BF heterogeneity among the QF muscles, yet blockade increased within-muscle BF heterogeneity in all four QF muscles ( P = 0.03). Taken together, these results show that BF becomes less heterogeneous with increasing exercise intensity in the QF muscle group. Adenosine seems to play a role in muscle BF heterogeneity even in the absence of changes in bulk BF at low and moderate one-leg intermittent isometric exercise intensities.
Effects of aging on adipose resistance artery vasoconstriction: possible implications for orthostatic blood pressure regulation
Authors: Ramsey Michael W. , Behnke Bradley J. , Prisby Rhonda D. , Delp Michael D.
Published: September 2007

The purpose of this investigation was to determine mean arterial pressure (MAP) and regional vascular conductance responses in young and aged Fisher-344 rats during orthostatic stress, i.e., 70° head-up tilt (HUT). Both groups demonstrated directionally different changes in MAP during HUT (young, 7% increase; aged, 7% decrease). Vascular conductance during HUT in young rats decreased in most tissues but largely remained unchanged in the aged animals. Based on the higher vascular conductance of white adipose tissue from aged rats during HUT, resistance arteries from white visceral fat were isolated and studied in vitro. There was diminished maximal vasoconstriction to phenylephrine and norepinephrine (NE: young, 42 ± 5%; old, 18 ± 6%) in adipose resistance arteries from aged rats. These results demonstrate that aging reduces the ability to maintain MAP during orthostatic stress, and this is associated with a diminished vasoconstriction of adipose resistance arteries.
Bronchodilatory effect of deep inspiration on the dynamics of bronchoconstriction in mice
Authors: Bates Jason H. T. , Cojocaru Ana , Lundblad Lennart K. A.
Published: September 2007

We recently developed a computational model of an airway embedded in elastic parenchyma (Bates JH, Lauzon AM. J Appl Physiol 102: 1912–1920, 2007) that accurately mimics the time dependence of airway resistance on tidal volume and positive end-expiratory pressure (PEEP) following methacholine injection in normal animals. In the present study, we compared the model predictions of bronchodilation induced by a deep inflation (DI) of the lung following administration of the bronchial agonist methacholine to corresponding experimental measurements made in mice. We found that a DI in mice caused an immediate reduction in airway resistance when it was administered soon after intravenous injection of methacholine, while the airway smooth muscle was in the process of contracting. However, the magnitude of the reduction in resistance was greater and its subsequent rate of increase less than that predicted by the model. We found that this effect was most pronounced when the DI was given within ∼3 s following methacholine injection, again in contrast to the predictions of the model. The reduction of airway resistance was virtually independent of the rate of lung inflation during the DI, however, which agrees with model predictions. We conclude that while the model accounts for a substantial fraction of the post-DI reduction in airway resistance seen experimentally, there remain important differences between prediction and experiment that suggest that the effects of a DI are not simply due to eccentric contraction of the airway smooth muscle.
ACE ID genotype affects blood creatine kinase response to eccentric exercise
Authors: Yamin Chen , Amir Offer , Sagiv Moran , Attias Eric , Meckel Yoav , Eynon Nir , Sagiv Michael , Amir Ruthie E.
Published: September 2007

Unaccustomed exercise may cause muscle breakdown with marked increase in serum creatine kinase (CK) activity. The skeletal muscle renin-angiotensin system (RAS) plays an important role in exercise metabolism and tissue injury. A functional insertion ( I)/deletion ( D) polymorphism in the angiotensin I-converting enzyme ( ACE) gene (rs4646994) has been associated with ACE activity. We hypothesized that ACE ID genotype may contribute to the wide variability in individuals' CK response to a given exercise. Young individuals performed maximal eccentric contractions of the elbow flexor muscles. Pre- and postexercise CK activity was determined. ACE genotype was significantly associated with postexercise CK increase and peak CK activity. Individuals harboring one or more of the I allele had a greater increase and higher peak CK values than individuals with the DD genotype. This response was dose-dependent (mean ± SE U/L: II, 8,882 ± 2,362; ID, 4,454 ± 1,105; DD, 2,937 ± 753, ANOVA, P = 0.02; P = 0.009 for linear trend). Multivariate stepwise regression analysis, which included age, sex, body mass index, and genotype subtypes, revealed that ACE genotype was the most powerful independent determinant of peak CK activity (adjusted odds ratio 1.3, 95% confidence interval 1.03–1.64, P = 0.02). In conclusion, we indicate a positive association of the ACE ID genotype with CK response to strenuous exercise. We suggest that the II genotype imposes increased risk for developing muscle damage, whereas the DD genotype may have protective effects. These findings support the role of local RAS in the regulation of exertional muscle injury.
Precursor Lesions of the Adrenal Gland
Authors: van Nederveen F.H. , de Krijger R.R.
Published: September 2007

Objective: To review the existing literature for evidence that adrenocortical and adrenomedullary tumours develop through a multistep process of carcinogenesis. Results: In the adrenal cortex hyperplasia and adenomas are frequently observed tumours or tumour-like conditions. In contrast, adrenocortical carcinomas are rare. Based on well-validated histopathological scoring systems, benign and malignant adrenocortical tumours can be separated, although a small subset of tumours remains hard to classify. Although extensive follow-up studies might argue against multistep carcinogenesis, analysis of chromosomal imbalances and gene expression profiling studies in these tumours are inconclusive and could give support for both multistep pathogenesis or de novo genesis of carcinomas. A major limit to most of these studies is the small sample size and the lack of extensive clinical (follow-up) data. In the adrenal medulla, pheochromocytomas (PCC) are the most frequent tumours in adults, with an incidence of 8 per million. They can be divided into benign and malignant PCC, but the distinction can only be made when metastases are present. Arbitrarily, lesions of less than 1 cm in diameter are called hyperplastic, but it should be expected that the majority of these are early lesions and if left in situ would grow to classify as PCC. In contrast to cortical tumours, the frequent 1p and 3q loss as an early event in tumourigenesis of benign PCC is verified in multiple studies. However, studies in malignant PCC yield divergent results, due to the small numbers analysed. Conclusion: Taken together, there appears to be a relationship between cortical and medullary hyperplasia on the one hand and cortical adenomas and PCC on the other. However, whether there is a transition from benign to malignant tumours, both cortical and medullary, remains to be determined.
Diabetes Provides an Unfavorable Environment for Muscle Mass and Function after Muscle Injury in Mice
Authors: Vignaud A. , Ramond F. , Hourdé C. , Keller A. , Butler-Browne G. , Ferry A.
Published: September 2007

It is of common knowledge that diabetes decreases skeletal muscle contractility and induces atrophy. However, how hyperglycemia and insulin deficiency modify muscle mass and neuromuscular recovery after muscle injury is not well known. We have analyzed two models of diabetes: streptozotocin (STZ)-treated Swiss mice and Akita mice that spontaneously develop diabetes. A fast muscle, the tibialis anterior, was injured following injection of a myotoxic agent (cardiotoxin). Neuromuscular function was evaluated by examining in situ isometric contractile properties of regenerating muscles in response to nerve stimulation 14, 28 and 56 days after myotoxic injury. We found that STZ-induced diabetes reduces muscle weight and absolute maximal tetanic force in both regenerating and uninjured muscles (p = 0.0001). Moreover, it increases specific maximal tetanic force and tetanic fusion in regenerating and uninjured muscles (p = 0.04). In the Akita mice, diabetes decreases muscle weight and absolute maximal tetanic force, and increases tetanic fusion in both regenerating and uninjured muscles (p ≤ 0.003). Interestingly, STZ-induced diabetes exerts more marked effects than diabetes of genetic origin, in particular on muscle weight. This reduction in muscle mass was not due to an increased expression of the atrogenes MuRF1 and atrogin-1 during STZ-induced diabetes. The present study in mice demonstrates that both models of diabetes impair regenerating muscles as well as uninjured muscles. Regenerating fast muscles are weaker, lighter and slower in diabetic compared with nondiabetic mice.
Helicobacter pylori-Associated Gastritis Is Related to babA2 Expression without Heterogeneity of the 3′ Region of the cagA Genotype in Gastric Biopsy Specimens
Authors: Xie X.F. , Ito M. , Sumii M. , Tanaka S. , Yoshihara M. , Chayama K.
Published: September 2007

Background: Cytotoxin-associated gene A (cagA) is the major virulence factor of Helicobacter pylori strains and affects the clinical outcome of patients. Blood group antigen binding adhesin (BabA) helps the strains adhere to the epithelial cell layer and is the most important adhesin of H. pylori.Objectives: We tried to study the association between the status of babA2 and cagA in H. pylori strains and histological gastritis. Methods: Thirty-six patients were included. RNA was extracted from two frozen biopsy samples of the antrum and corpus, respectively, and cagA/babA2 genotypes were analyzed with reverse transcription polymerase chain reaction and direct sequencing. Two gastric specimens of the antrum and corpus, respectively, were also stained with hematoxylin and eosin to analyze H. pylori-related gastritis. Results: In the antrum, 56% of the specimens were babA2 positive and in the corpus 53%. The gastritis scores of activity and inflammation were associated with the presence of babA2 in antrum specimens but not in corpus specimens. cagA gene encoding in the CagA EPIYA-D region was detected in all samples, and the sequence was completely identical between those from the gastric corpus and antrum. Conclusion:babA2 expression is heterogeneous and correlated with the extent of gastritis in the antrum, but not in the corpus, whereas cagA shows a monotonous genotype.
Supplementation with High-Dose Ascorbic Acid Improves Intestinal Anastomotic Healing
Authors: Cevikel M.H. , Tuncyurek P. , Ceylan F. , Meteoglu I. , Kozaci D. , Boylu S.
Published: September 2007

Background/Aim: Ascorbic acid modulates tissue healing but the value of ascorbic acid supplementation during anastomotic healing remains unclear. We examined the role of ascorbic acid treatment in experimental intestinal resection. Methods: Male Wistar albino rats (n = 30) were divided into three groups: sham treatment (group 1), and daily ascorbic acid treatment with 100 mg/kg (group 2) or 200 mg/kg (group 3) via the intramuscular route. Following sacrifice on the 7th postoperative day, bursting pressure of the anastomoses was measured. Hydroxyproline assessment and histological analysis were carried out. Results: The bursting pressure values of groups 2 (171.4 ± 4.3 mm Hg) and 3 (196.4 ± 2.2 mm Hg) were higher than that of group 1 (139.1 ± 4.1 mm Hg; p < 0.05). In addition, the hydroxyproline level of group 3 (249.2 ± 25.1 µg/mg) was higher than that of groups 1 (157.9 ± 14.9 µg/mg) and 2 (187.9 ± 14.8 µg/mg; p < 0.05). The histopathological scores indicated improved healing in groups 3 (6.0 ± 0.2) and 2 (4.4 ± 0.4), compared to group 1 (2.7 ± 0.3; p < 0.05). Conclusion: In the present study, supraphysiologic doses of ascorbic acid improved anastomotic healing. Therefore, vitamin C supplementation poses as a beneficial treatment in the context of collagen accumulation, inflammatory response, and anastomotic strength. However, the clinical value of high-dose ascorbic acid supplementation in the clinical setting is yet to be established.
Intraoperative Cochlear Nerve Monitoring in Vestibular Schwannoma Surgery – Does It Really Affect Hearing Outcome?
Authors: Piccirillo Enrico , Hiraumi Harukazu , Hamada Masashi , Russo Alessandra , De Stefano Alessandro , Sanna Mario
Published: September 2007

Objective: The objective of this study was to examine the usefulness of intraoperative cochlear nerve monitoring (ICNM) in the preservation of normal and social hearing in vestibular schwannoma (VS) removal. Methods: A retrospective chart review was conducted. Of 1315 patients operated for VS between June 1988 and December 2005, 150 patients were subjected to hearing preservation surgery. Among these, 99 patients with preoperative normal and social hearing (class A and B in the modified Sanna classification) and with a small tumor <1.5 cm in size were included in the analysis. The difference in hearing preservation rates between patients operated with and without ICNM was statistically examined using Fisher’s exact test. An initial analysis was conducted for the total group. Patients were then divided into two subgroups according to the surgical approach (middle cranial fossa and retrosigmoid-retrolabyrinthine). The effectiveness of ICNM in each subgroup was analyzed. Results: The hearing preservation rate was 26.7% in cases operated with ICNM and 20.8% in cases without ICNM. The difference did not reach statistical significance (p = 0.79). In subgroup analyses, the ICNM did not prove to contribute to the significantly higher hearing preservation rate. Conclusions: ICNM did not increase the ratio of patients with postoperative normal and social hearing in VS surgery.
cDNA Microarray Analysis of Adaptive Changes after Renal Ablation in a Sclerosis-Resistant Mouse Strain
Authors: Rumberger Brigitta , Vonend Oliver , Kreutz Clemens , Wilpert Jochen , Donauer Johannes , Amann Kerstin , Rohrbach Rolf , Timmer Jens , Walz Gerd , Gerke Peter
Published: September 2007

Background:5/6 nephrectomy (Nx) in susceptible animals causes glomerular sclerosis and interstitial fibrosis in the remnant kidney. Oxidative stress, transforming growth factor-β (TGF-β), and the de novo synthesis of collagen seem to contribute to this process. However, these factors might also be required for tissue repair without fibrosis. Methods:We examined dynamic changes after nephron loss in a mouse strain capable of complete recovery. C57BL/6 mice underwent single-session Nx and were followed for 40 weeks. Gene expression was monitored over 20 days using 22,000 cDNA microarrays. Results:The mice developed transient hypertension and glomerular hypertrophy after Nx but failed to progress to glomerular sclerosis or renal failure. Gene expression profiles revealed three stages of recovery, an early phase of injury response, an intermediate phase of extracellular matrix (ECM) production and a later phase of reconstitution. Surprisingly, oxidative stress responses and collagen production were strongly upregulated soon after Nx. Furthermore, TGF-β1 and connective tissue growth factor were rapidly upregulated and remained elevated. Conclusion:We suggest that oxidative stress, collagen production, profibrotic growth factors and ECM turnover are part of the comprehensive adaptation to nephron loss and not necessarily associated with progressive loss of renal function.
Combined Effects of Carbonic Anhydrase Inhibitor and Adenosine A1 Receptor Antagonist on Hemodynamic and Tubular Function in the Kidney
Authors: Miracle Cynthia M. , Rieg Timo , Blantz Roland C. , Vallon Volker , Thomson Scott C.
Published: September 2007

Background: Carbonic anhydrase inhibitors (CAI) reduce proximal reabsorption, activating tubuloglomerular feedback (TGF) and reducing glomerular filtration rate (GFR). Adenosine A1 receptors (A1R) mediate the TGF response and stimulate proximal reabsorption. Methods: Clearance and micropuncture studies were performed in Wistar rats to determine whether blockade of A1R (KW3902 0.3 mg/kg i.v.) would prevent CAI (benzolamide 5 mg/kg i.v.) from lowering GFR, whether CAI and KW3902 exert additive effects on sodium excretion, and to what extent such interactions depend on events in the glomerulus, proximal tubule, or distal nephron. Results: KW3902 raised GFR and prevented CAI from lowering GFR. KW3902 and CAI caused additive diuresis and natriuresis. KW3902 and CAI increased lithium clearance, but their effects were redundant. CAI increased the dependence of proximal reabsorption on active chloride transport. KW3902, alone, did likewise, but to a lesser extent than CAI. Adding KW3902 to CAI lessened the shift toward active chloride transport. Conclusions: The data reveal that A1R mediate glomerular vascular resistance whether or not TGF is activated, that additive effects of CAI and KW3902 on salt excretion occur, in part, because KW3902 inhibits reabsorption downstream from the macula densa, and that KW3902 likely inhibits proximal reabsorption by interfering with apical sodium-hydrogen exchange.
Ex vivo Expansion of Umbilical Cord Blood Stem Cells Using Different Combinations of Cytokines and Stromal Cells
Authors: Madkaikar Manisha , Ghosh Kanjaksha , Gupta Maya , Swaminathan Suchitra , Mohanty Dipika
Published: September 2007

Umbilical cord blood is a promising source of hematopoietic stem cells (HSC) for allogeneic transplantation. However, graft rejection and delayed engraftment remain major limitations, both of which are related to a limited number of stem cells in the cord blood graft. Ex vivo expansion of HSC has been suggested as one of the ways of overcoming the challenges caused by a limited hematopoietic cell number from cord blood stem cell transplantation. In this study, we quantified and characterized an ex vivo expansion capacity of cord blood-derived HSC in a liquid culture system under different conditions. These conditions included: the combinations and concentrations of hematopoietic growth factors [stem cell factor (SCF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-3, IL-6 and erythropoietin (EPO)], placental conditioning medium (PCM), and stromal cell support. During culture, the mean nucleated cell count, the mean CD34+ cell count, fold expansion, viability, clonogenic assays and immunophenotypic characterization were performed on day 0, day 7, day 12 and day 14 on the expanded cellular product. The maximum expansion was achieved using GF2 (SCF + IL-3 + GM-CSF) with stromal cell support. The mean CD34+ cell expansion on days 7 and 12 was 16.25- and 21.4-fold (5.2–32), respectively, and the mean nucleated cell expansion was 15.1- and 21-fold (18.1–23.2). The mean nucleated cell viability on day 12 was 87.9% (85.6–92.5). After 12 days, granulocyte-macrophage colony-forming units CFU-GEMM showed a 20.4-fold increase. A 21.4-fold increase in the CD34+ cells and a 20-fold increase in the CFU-GEMM should provide enough cells from a single cord blood unit to reduce the period of cytopenia after single unit cord blood transplantation. Even if there was some doubt about the long-term repopulating capacity of the expanded cells part of the collected umbilical cord cells (25%) could be expanded till day 12 after transplanting the major part (75%) of the collection.
Relationship between Behavioural and Psychological Symptoms of Dementia and Cognition in Alzheimer’s Disease
Authors: Starr John M. , Lonie Jane
Published: September 2007

Background: Behavioural and psychological symptoms of dementia (BPSDs) are common. It is unclear whether associations are stronger with the absolute cognitive level or that relative to premorbid mental ability. Methods: The Neuropsychiatric Inventory (NPI) was administered to carers of patients with Alzheimer’s disease (AD). Patients underwent cognitive testing with the National Adult Reading Test (NART) to estimate premorbid IQ and 6 tests of current cognitive function. Results: 556 patients, mean age 77.3 years, had NPI scores. The total NPI score correlated significantly with most cognitive test scores, but multi-linear regression identified NART-IQ as the only significant cognitive predictor (β = –0.17, p = 0.008). Principal component analysis of the 10 NPI domains extracted 3 components corresponding to mood, frontal and psychotic factors. The NPI mood factor correlated significantly with NART-IQ (ρ = –0.14, p = 0.014) and lexical verbal fluency (ρ = –0.09, p = 0.034) only. The NPI frontal factor correlation with NART-IQ approached significance (ρ = –0.11, p = 0.053). The NPI psychotic factor correlated significantly with the Mini-Mental State Examination (ρ = –0.15, p < 0.001) and the Hopkins verbal learning test (ρ = –0.11, p = 0.013) scores. Conclusion: The relationship between BPSDs and cognition in AD is weak and largely explained by premorbid IQ. There is a stronger relationship between current cognition and psychotic symptoms.
Frusemide Administration in Critically Ill Patients by Continuous Compared to Bolus Therapy
Authors: Ostermann Marlies , Alvarez George , Sharpe Michael D. , Martin Claudio M.
Published: September 2007

Background: Frusemide is frequently administered to critically ill patients in the intensive care unit (ICU). We investigated whether continuous frusemide infusion therapy was more effective than regular intermittent bolus doses at causing diuresis. Methods: 59 adult patients with fluid overload admitted to two tertiary multidisciplinary ICUs were randomised to either a continuous frusemide infusion or regular intermittent intravenous boluses of frusemide according to pre-defined algorithms aiming for a minimum hourly urine output. Results: There was no significant difference in diuretic response between the two groups during the first 24 h (5.3 liters in the bolus group vs. 5.4 liters in the infusion group). In the bolus group a significantly higher dose of frusemide was needed to achieve target diuresis (24.1 vs. 9.2 mg/h in the infusion group, p = 0.0002). Mean urine output per dose of frusemide was significantly higher in the infusion group (31.6 vs. 18 ml/mg in the bolus group, p = 0.014). At the end of the study, there were no differences in hospital mortality, number of patients requiring ventilatory support, change in serum creatinine or change in estimated glomerular filtration rate. Conclusions: Both intermittent boluses and continuous infusion of frusemide were successful in achieving algorithm-driven diuresis. However, continuous infusion therapy was more effective than intermittent boluses since the dose of frusemide required was significantly less.
Prevention of Hypertension with or without Renin-Angiotensin System Inhibition Precludes Nephrin Loss in the Early Stage of Experimental Diabetes Mellitus
Authors: Amazonas Roberto Bleuel , de Almeida Sanita Rodrigo , Kawachi Hiroshi , Lopes de Faria José B.
Published: September 2007

Background and Aims: Several lines of clinical evidence support the concept that the reduction of blood pressure may be useful in the prevention of diabetic kidney disease. In young diabetic spontaneously hypertensive rats (SHR), prevention of hypertension reduces several early renal abnormalities including albuminuria. However, the contribution of nephrin loss to albuminuria in this early stage of experimental diabetes is unknown. Therefore, we investigated whether elevation of albuminuria in young diabetic SHR is associated with nephrin loss, and if prevention of hypertension, with or without inhibition of the renin-angiotensin system, precludes these abnormalities. Methods: Diabetes was induced by streptozotocin injection in 4-week-old still normotensive SHR and their genetically normotensive control, Wistar-Kyoto rats. Diabetic SHR were randomized for no treatment, or treatment with captopril, losartan, or triple therapy (hydrochlorothiazide, reserpine and hydralazine) for 20 days. Results: The increase in systolic blood pressure was equally prevented by all treatments. Albuminuria was higher in diabetic SHR and similarly reduced (p < 0.05) by captopril, losartan, and triple therapy. Glomerular expression of nephrin was significantly reduced in diabetic SHR in comparison with non-diabetic controls. The antihypertensive treatment prevented the reduction in glomerular expression of nephrin. Conclusions: These results demonstrate that the loss of nephrin is associated with albuminuria in a model of genetic hypertension and diabetes, and that the prevention of development of hypertension restores nephrin and prevents albuminuria. This finding suggests a crucial role of blood pressure in diabetes as determinant of nephrin expression and albuminuria.
Expression of the Pkd1 Gene Is Momentously Regulated by Sp1
Authors: Jeon Jeong Ok , Yoo Kyung Hyun , Park Jong Hoon
Published: September 2007

Background: Autosomal dominant polycystic kidney disease (ADPKD) is a common human genetic disease that is caused by a mutation of a single gene inherited from either parent. Mutations in the Pkd1 gene result in the formation of multiple fluid-filled cysts in kidneys. In previous studies, the functional regulatory sequences of Pkd1 promoter region were detected by the use of comparative genome analysis. Methods: To investigate the transcriptional regulation of the Pkd1 gene, the Pkd1 promoter was isolated. This promoter contains three Sp1-binding sites. Two of the sites which are found in a 300 bp fragment (–127 to +157) were mutated. An electrophoretic mobility shift assay (EMSA) was performed to determine which transcription factors are bound to Pkd1. Results: Based on studies using a luciferase assay, the Sp1-A site (the nearest Sp1 to the ATG start codon) is more important for activation of Pkd1. The result of EMSA showed that Sp1 transcription factor binds with Pkd1 promoter regions. Conclusions: Two of the Sp1 sites were found in a proximal promoter region of Pkd1 (–127 to +157). Sp1 sites affect an important role in the activation of the gene. Especially, the Sp1-A site is more important for expression of Pkd1.
Interaction of Alpha-Actinin-4 with Class I PxxP Motif-Containing OK/SW-CL.16 Protein
Authors: Togashi Masaru , Okuyama Shin , Wakui Hideki , Komatsuda Atsushi , Suzuki Daisuke , Toyoda Masao , Sawada Ken-ichi
Published: September 2007

Background: The aim of this study was to identify novel binding partners for α-actinin-4 (actinin-4), an essential component of the glomerular filtration barrier.Methods: We performed bacterial two-hybrid screenings of a human kidney cDNA library using as a bait human actinin-4 containing the spectrin-like repeat R1. The identified interactions were further verified by in vitro affinity assays. To investigate the expression of the identified molecules in the kidney and other tissues, a human tissue cDNA panel screening and in situ hybridization were performed. Results: One isolated cDNA from the library encoded OK/SW-CL.16 protein with a segment similar to known actinin-interacting regions. OK/SW-CL.16 protein also contained the class I PxxP motif, which can participate in binding to Src homology 3 (SH3) domain-containing signaling proteins. In vitro affinity assays showed interactions of recombinant actinin-4 R1 and full-length renal actinin-4 with recombinant OK/SW-CL.16 protein. A tissue cDNA panel screening revealed a ubiquitous expression of OK/SW-CL.16 mRNA.In situ hybridization showed glomerular expression of OK/SW-CL.16 mRNA, mainly in podocytes and mesangial cells. Conclusion: Our results suggest that OK/SW-CL.16 protein is a novel binding partner for actinin-4. OK/SW-CL16 protein might act as a linker between actinin-4 and some SH3 domain-containing signaling proteins in podocytes.
TNF-Alpha and IL-1Beta-Mediated Regulation of MMP-9 and TIMP-1 in Human Glomerular Mesangial Cells
Authors: Nee Larine , Tuite Niamh , Ryan Michael P. , McMorrow Tara
Published: September 2007

Background: Renal cells such as mesangial cells are known to secrete metalloproteinases that are capable of degrading the constituents of the glomerular basement membrane (GBM). Disruption of the GBM via cytokine-induced alterations in matrixmetalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) may be an important mechanism in the renal disease process. In renal disease, both resident renal cells and infiltrating immune cells are capable of secreting pro-inflammatory cytokines including tumour necrosing factor-α (TNFα) and interleukin-1β (IL-1β). In this study, we examine the potential of these cytokines to alter levels of MMPs and TIMPs in human mesangial cells. Methods: The T-HMC human mesangial cell line was cultured in RPMI 1640 containing 5% serum. Cells at confluency were serum starved for 24 h prior to exposure to TNF-α (0.1–100 ng/ml) or IL-1β (0.1–100 ng/ml) or a combination of both for 48 h. Activity of MMP-9 was examined by gelatin zymography and TIMP-1 expression was analysed by Western blotting. Results: TNF-α but not IL-1β resulted in a dose-dependent increase in the latent form of MMP-9 and a decrease in TIMP-1 production. Co-treatment with IL-1β had no effect on the induction of MMP-9 but increased the inhibition of TIMP-1 in the presence of TNF-α. Inhibition of PKC provided evidence of the importance of this pathway in mediating the TNF-α-induced suppression of TIMP-1. Activation of the ERK 1/2 MAPK mediated both the upregulation of MMP-9 and the inhibition of TIMP-1 following TNF-α treatment. p38 MAPK activation was also found to be involved in the TNF-α-stimulated MMP-9. Conclusion: The cytokine TNF-α causes different effects on human mesangial MMP-9 and TIMP-1 expression which are mediated through the TNF-RI, and the different signalling pathways of PKC, ERK 1/2 and p38 MAPK. This suggests an important role for pro-inflammatory cytokines in renal disease progression.
Clinical Isolation and Characterization of Yersinia enterocolitica in China Using Real-Time PCR and Culture Method
Authors: Zheng Haoxuan , Wang Jide , Sun Yong , Jiang Bo
Published: September 2007

Objective: To carry out a preliminary epidemiological investigation of Yersinia enterocolitica from a clinical perspective in China and to further validate the consistency of real-time polymerase chain reaction (RT-PCR) and culture method. Methods: 700 stool samples were randomly and continuously collected from in- and outpatients with diarrhea, which were detected by both the culture method and RT-PCR. Results: All 52 positive samples were successfully detected by both RT-PCR and the culture method. The total incidence of yersiniosis was about 7.4%, which was statistically higher than before (0.65%) by the Mann-Whitney U test. The morbidity was not significant between males and females (U = 0.354, p > 0.05) by the Mann-Whitney U test whereas it was significant between children and adults (U = 2.06, p < 0.05) as well as between the autumn-winter and spring-summer (U = 2.04, p < 0.05) months. Moreover, the constituent ratio of children and adults with yersiniosis in different systems was not significant by the McNemer test while it was significant between children and adults in the incidence of extraintestinal infection (U = 2.51, p < 0.05). Conclusion: RT-PCR with better applicability will become an efficient tool for detection of virulent Y. enterocolitica and will also be used as an alternative to the culture method. Due to the higher incidence than before, we should publicize dietary hygiene and pay more attention to earlier diagnosis for yersiniosis and its complications, aiming at children <4 years and adults >60 years during the autumn-winter months.
Cardiac Biomarkers in Haemodialysis Patients: The Prognostic Value of Amino-Terminal Pro-B-Type Natriuretic Peptide and Cardiac Troponin T
Authors: Sommerer Claudia , Giannitsis Evangelos , Schwenger Vedat , Zeier Martin
Published: September 2007

Cardiac biomarkers such as amino-terminal pro-B-type natriuretic peptide (NT-proBNP) and cardiac troponin T (cTNT) provide information on cardiovascular morbidity and mortality in patients with normal renal function. In a considerable number of chronic haemodialysis patients, both biomarkers – NT-proBNP and cTNT – are elevated despite the absence of cardiac ischaemia. The elevation of cardiac biomarkers in chronic haemodialysis patients is of prognostic value with respect to cardiovascular morbidity and mortality. They provide a useful rationale for the screening of occult cardiac disease and optimization of the dialysis procedure with respect to volume control.
Do Biochemical Measures Change in Living Kidney Donors?
Authors: Young Ann , Nevis Immaculate F.P. , Geddes Colin , Gill John , Boudville Neil , Storsley Leroy , Garg Amit X.
Published: September 2007

Background: Living kidney donation provides a unique opportunity to assess possible biochemical changes attributable to small decrements in glomerular filtration rate. We reviewed studies which followed 5 or more healthy donors, where changes in biochemical measures or anemia were assessed at least 4 months after nephrectomy. Methods: We searched MEDLINE, EMBASE, and Science Citation databases, and reviewed reference lists from 1966 through June 2006. We abstracted data on study and donor characteristics and biochemical outcomes of interest. Results: Eight studies examined at least one outcome of interest. The average time after donation ranged from 0.4 to 11 years, the postdonation creatinine clearance ranged from 73 to 99 ml/min, and the decrement after donation ranged from 11 to 38 ml/min. Nephrectomy did not change hemoglobin, erythropoietin, serum phosphate, calcium or C-reactive protein levels. The studies were inconsistent as to whether parathyroid hormone levels increased and 1,25-dihydroxyvitamin D levels decreased after nephrectomy. Uric acid levels increased variably post-donation. Plasma homocysteine increased in the single study included in this review. Conclusions: The mechanistic changes described above and their prognostic significance need clarification. Based on existing evidence, it is not necessary to routinely monitor living kidney donors for changes in these biochemical measures.
A Change from Subcutaneous to Intravenous Erythropoietin Increases the Cost of Anemia Therapy
Authors: McFarlane Philip A. , Hillmer Michael P. , Dacouris Niki
Published: September 2007

Background: It seems that more erythropoietin (EPO) is required when given intravenously (IV) than when given subcutaneously (SC). Estimates of the magnitude of this difference vary widely, impeding development of economic models in this area. Concerns about pure red cell aplasia led our program to switch from SC to IV EPO, so we studied the impact of this change on the cost of anemia therapy. Methods: All in-center hemodialysis patients who had received EPO for at least 3 months prior to and following conversion to IV EPO were studied. Data was obtained retrospectively for 1 year prior to and prospectively for 1 year following conversion. The costs of anemia therapy (EPO, transfusions and iron) were calculated from the hospital’s perspective. Results: 158 patients were studied. One month after switching, the hemoglobin fell significantly, reaching a nadir at 3 months. This triggered more use of EPO, iron and transfusions. By month 7 hemoglobin levels had returned to initial levels, with a median rise in EPO dose of 1,250 units/week (p < 0.001). After the switch, the median rise in total anemia therapy costs was 13.1% (CAD 665/patient-year, p < 0.01). Conclusions: Conversion of EPO from SC to IV dosing increased the costs of anemia therapy at our center.