260 results match your criteria: "Steele Memorial Children's Research Center[Affiliation]"

Sp1 and Sp3 mediate NHE2 gene transcription in the intestinal epithelial cells.

Am J Physiol Gastrointest Liver Physiol

July 2007

Department of Pediatrics, Steele Memorial Children's Research Center, 1501 N. Campbell Ave., Tucson, AZ 85724, USA.

Our previous studies have identified a minimal Sp1-driven promoter region (nt -36/+116) directing NHE2 expression in mouse renal epithelial cells. However, this minimal promoter region was not sufficient to support active transcription of NHE2 gene in the intestinal epithelial cells, suggesting the need for additional upstream regulatory elements. In the present study, we used nontransformed rat intestinal epithelial (RIE) cells as a model to identify the minimal promoter region and transcription factors necessary for the basal transcription of rat NHE2 gene in the intestinal epithelial cells.

View Article and Find Full Text PDF

Mouth-to-mouth rescue breathing is a barrier to the performance of bystander cardiopulmonary resuscitation. Experimental data suggest that mouth-to-mouth rescue breathing may not be necessary for brief periods of bystander cardiopulmonary resuscitation until defibrillation is available. These data are insufficient to recommend changes in cardiopulmonary resuscitation guidelines, but are compelling enough to recommend further experimental and human trials.

View Article and Find Full Text PDF

HSP90: a rising star on the horizon of anticancer targets.

Future Oncol

August 2005

Whitehead Institute for Biomedical Research, Room 649, 9 Cambridge Center, Cambridge, MA 02142, and University of Arizona, Steele Memorial Children's Research Center, Tucson, AZ 85724, USA.

Over the past decade, heat-shock protein (HSP)90 has begun to draw increasing attention as a novel anticancer target with unique features. As a molecular chaperone, HSP90 promotes the maturation and maintains the stability of a large number of conformationally labile client proteins, most of which are involved in biologic processes that are often deranged within tumor cells, such as signal transduction, cell-cycle progression and apoptosis. As a result, and in contrast to other molecular targeted therapeutics, inhibitors of HSP90 achieve their promising anticancer activity through simultaneous disruption of many oncogenic substrates within cancer cells.

View Article and Find Full Text PDF

HSP90 and the chaperoning of cancer.

Nat Rev Cancer

October 2005

Steele Memorial Children's Research Center, University of Arizona, Tucson, Arizona 85724, USA.

Standing watch over the proteome, molecular chaperones are an ancient and evolutionarily conserved class of proteins that guide the normal folding, intracellular disposition and proteolytic turnover of many of the key regulators of cell growth, differentiation and survival. This essential guardian function is subverted during oncogenesis to allow malignant transformation and to facilitate rapid somatic evolution. Pharmacologically 'bribing' the essential guard duty of the chaperone HSP90 (heat-shock protein of 90 kDa) seems to offer a unique anticancer strategy of considerable promise.

View Article and Find Full Text PDF

Chaperone-rich cell lysates, immune activation and tumor vaccination.

Cancer Immunol Immunother

March 2006

Department of Pediatrics, Steele Memorial Children's Research Center, University of Arizona, 1501 N. Campbell Ave., PO Box 245073, Tucson, AZ 85724-5073, USA.

We have utilized a free-solution-isoelectric focusing technique (FS-IEF) to obtain chaperone-rich cell lysates (CRCL) fractions from clarified tumor homogenates. The FS-IEF technique for enriching multiple chaperones from tumor lysate is relatively easy and rapid, yielding sufficient immunogenic material for clinical use. We have shown that tumor-derived CRCL carry antigenic peptides.

View Article and Find Full Text PDF

Molecular physiology of vesicular glutamate transporters in the digestive system.

World J Gastroenterol

March 2005

Departments of Pediatrics, Room 3325, Steele Memorial Children's Research Center, University of Arizona Health Sciences Center, Tucson, AZ 85724, USA.

Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system (CNS). Packaging and storage of glutamate into glutamatergic neuronal vesicles require ATP-dependent vesicular glutamate uptake systems, which utilize the electrochemical proton gradient as a driving force. Three vesicular glutamate transporters (VGLUT1-3) have been recently identified from neuronal tissue where they play a key role to maintain the vesicular glutamate level.

View Article and Find Full Text PDF

Objectives: This study was designed to compare outcome after adult defibrillation dosing versus pediatric dosing in a piglet model of prolonged prehospital ventricular fibrillation (VF).

Background: Weight-based 2 to 4 J/kg monophasic defibrillation dosing is recommended for children in VF, but impractical for automated external defibrillator (AED) use. Present AEDs can only provide adult shock doses or newly developed attenuated adult doses intended for children.

View Article and Find Full Text PDF

Post-shock chest compression delays with automated external defibrillator use.

Resuscitation

March 2005

Department of Pediatrics, Steele Memorial Children's Research Center, Sarver Heart Center, University of Arizona College of Medicine, P.O. Box 245073, 1501 N Campbell Avenue, Tucson, AZ 85724, USA.

Primary Objective: In a swine model of out-of-hospital ventricular fibrillation (VF) cardiac arrest, we established that automated external defibrillator (AED) defibrillation could worsen outcome from prolonged VF compared with manual defibrillation. Worse outcomes were due to substantial interruptions and delays in chest compressions for AED rhythm analyses and shock advice. In particular, the mean interval from first AED shock to first post-shock compressions was 46+/-6s.

View Article and Find Full Text PDF

Subcloning, localization, and expression of the rat intestinal sodium-hydrogen exchanger isoform 8.

Am J Physiol Gastrointest Liver Physiol

July 2005

Department of Pediatrics, Steele Memorial Children's Research Center, 1501 N. Campbell Ave., Tucson, AZ 85724, USA.

Apically expressed intestinal and renal sodium-hydrogen exchangers (NHEs) play a major role in Na(+) absorption. Our previous studies on NHE ontogeny have shown that NHE-2 and NHE-3 are expressed at very low levels in young animals. Furthermore, single and/or double NHE-2 and NHE-3 knockout mice display no obvious abnormalities before weaning.

View Article and Find Full Text PDF

Background: Most out-of-hospital ventricular fibrillation (VF) is prolonged (>5 minutes), and defibrillation from prolonged VF typically results in asystole or pulseless electrical activity. Recent visual epicardial observations in an open-chest, open-pericardium model of swine VF indicate that blood flows from the high-pressure arterial system to the lower-pressure venous system during untreated VF, thereby overdistending the right ventricle and apparently decreasing left ventricular size. Therefore, inadequate left ventricular stroke volume after defibrillation from prolonged VF has been postulated as a major contributor to the development of pulseless rhythms.

View Article and Find Full Text PDF

Managing Henoch-Schonlein purpura in children with fish oil and ACE inhibitor therapy.

Nephrology (Carlton)

December 2004

Department of Pediatrics, Steele Memorial Children's Research Center, University of Arizona, Tucson, Arizona 85724, USA.

Background: Henoch-Schonlein purpura (HSP) is a vasculitic syndrome with palpable purpura and renal involvement. The treatment for HSP with persistent renal disease remains controversial. The kidney biopsy in HSP shows IgA deposits and fish-oil therapy has proven to be promising in halting the progression of IgA nephropathy.

View Article and Find Full Text PDF

Identification of differentially expressed genes in response to dietary iron deprivation in rat duodenum.

Am J Physiol Gastrointest Liver Physiol

May 2005

Department of Pediatrics, Steele Memorial Children's Research Center, University of Arizona, 1501 N. Campbell Ave., Tucson, Arizona 85724, USA.

We sought to identify novel genes involved in intestinal iron absorption by inducing iron deficiency in rats during postnatal development from the suckling period through adulthood. We then performed comparative gene chip analyses (RAE230A and RAE230B chips; Affymetrix) with cRNA derived from duodenal mucosa. Real-time PCR was used to confirm changes in gene expression.

View Article and Find Full Text PDF

Bacteriuria management and urological evaluation of patients with spina bifida and neurogenic bladder: a multicenter survey.

J Urol

January 2005

Department of Pediatrics and Steele Memorial Children's Research Center, University of Arizona Health Sciences Center, 1501 North Campbell Avenue, Tucson, Arizona 85724, USA.

Purpose: We assessed how groups at spina bifida clinics evaluate and manage the urinary tract in patients with spina bifida, neurogenic bladder and bacteriuria.

Materials And Methods: A survey was mailed to all 169 clinics listed by the Spina Bifida Association of America. Survey items addressed baseline and surveillance evaluation, criteria used to assess urinary tract health and approaches to treatment in patients with spina bifida and neurogenic bladder.

View Article and Find Full Text PDF

Effects of angiotensin II on NaPi-IIa co-transporter expression and activity in rat renal cortex.

Biochim Biophys Acta

December 2004

Department of Pediatrics, Steele Memorial Children's Research Center, University of Arizona Health Sciences Center, 1501 N. Campbell Avenue, Tucson, AZ 85724, USA.

The kidney plays a major role in reabsorption of phosphate with the majority occurring in the proximal tubule (PT). The type IIa sodium-phosphate co-transporter (NaPi-IIa) is the main player in PT. The purpose of current study was to determine the effect of angiotensin II (A-II) on membrane expression of NaPi-IIa in the rat renal cortex.

View Article and Find Full Text PDF

Molecular cloning and characterization of a human urate transporter (hURAT1) gene promoter.

Biochim Biophys Acta

November 2004

Department of Pediatrics, Steele Memorial Children's Research Center, University of Arizona Health Sciences Center, Room 3325, 1501 North Campbell Avenue, Tucson, AZ 85724, USA.

We report the novel cloning and preliminary characterization of a human urate transporter (hURAT1) gene promoter. The transcription initiation site was mapped to a base 337 bp upstream of the ATG start codon by primer extension and 5'-RACE. The minimal functional promoter region is within 253 bp when the promoter/luciferase constructs were transfected into OK cells.

View Article and Find Full Text PDF

Cargo from tumor-expressed albumin inhibits T-cell activation and responses.

Cancer Res

November 2004

Department of Pediatrics, Steele Memorial Children's Research Center, University of Arizona, Arizona Health Sciences Center, Tucson, Arizona, USA.

In this study, we show that rodent albumin is expressed by and cell surface localized on at least some murine tumor cells. We have been able to purify this tumor-expressed albumin from in vivo grown tumor masses. The tumor-expressed albumin, unlike normal serum albumin purified from blood, is capable of inhibiting T-cell activation, proliferation, and function in both in vitro and in vivo settings.

View Article and Find Full Text PDF

Objective: To evaluate published data regarding the treatment of prolonged pediatric defibrillation, with special emphasis on the use of attenuated adult biphasic shocks for pediatric defibrillation.

Design: Review relevant human and animal literature.

Results: Rhythm analysis algorithms from two manufacturers of automated external defibrillators can accurately distinguish shockable from nonshockable rhythms in children.

View Article and Find Full Text PDF

The human intestinal type IIb Na+-P(i) cotransporter (hNaPi-IIb) gene promoter lacks a TATA box and has a high GC content in the 5'-flanking region. To understand the mechanism of hNaPi-IIb gene transcription, the current study was performed to characterize the minimal promoter region and transcriptional factor(s) necessary to activate gene expression in human intestinal cells (Caco-2). With the use of progressively shorter promoter constructs, a minimal promoter extending from bp -58 to +15 was identified and shown to direct high levels of hNaPi-IIb cotransporter expression in Caco-2 cells.

View Article and Find Full Text PDF

Drugs that inhibit the function of heat shock protein 90 (Hsp90) are of interest in the treatment of pediatric cancers because these agents deplete the cellular levels of signaling molecules that are important for the growth and survival of many childhood tumors. To generate preclinical data in anticipation of clinical trials of Hsp90 inhibitors in children, we evaluated the effects of the Hsp90 inhibitor geldanamycin (GA) alone and in combination with cis-platinum (II)-diamine dichloride (cisplatin) in pediatric tumor cells. Immunoblotting demonstrated depletion of the Hsp90 client proteins AKT and the type 1 insulin-like growth factor receptor (IGF1R) in a panel of pediatric tumor cell lines after exposure to GA.

View Article and Find Full Text PDF

The PHEX gene encodes an endopeptidase expressed in osteoblasts that inactivates an uncharacterized peptide hormone, phosphatonin, which suppresses bone mineralization as well as renal phosphate reabsorption and vitamin D bioactivation. We demonstrate that 1alpha-25-dihydroxyvitamin D (1,25(OH)2D3), the, active renal vitamin D metabolite, decreases PHEX mRNA in the rat osteoblastic cell line, UMR-106, as well as in mouse calvaria. Promoter/reporter construct analysis of the murine PHEX gene in transfected UMR-106 cells localized the repressive effect of 1,25(OH)2D3 to the -133 to -74 bp region, and gel mobility shift experiments revealed that 1,25(OH)2D3 treatment of the cells diminished the binding of a nuclear protein(s) to a stretch of 17 adenines from bp -116 to -100 in the proximal PHEX promoter.

View Article and Find Full Text PDF

Effect of angiotensin-II on renal Na+/H+ exchanger-NHE3 and NHE2.

Biochim Biophys Acta

July 2004

Department of Pediatrics and Physiology, Steele Memorial Children's Research Center, University of Arizona Health Sciences Center, 1501 N. Campbell Avenue, Tucson, AZ 85724, USA.

The purpose of the present study was to determine the effect of angiotensin II (A-II) on membrane expression of Na+/H+ exchange isoforms NHE3 and NHE2 in the rat renal cortex. A-II (500 ng/kg per min) was chronically infused into the Sprague-Dawley rats by miniosmotic pump for 7 days. Arterial pressure and circulating plasma A-II level were significantly increased in A-II rats as compared to control rats.

View Article and Find Full Text PDF

Transient hypothyroidism in a breastfed infant after maternal use of iodoform gauze.

J Pediatr Endocrinol Metab

April 2004

Steele Memorial Children's Research Center, Department of Pediatrics, University of Arizona, Tucson, AZ, USA.

We describe transient hypothyroidism induced in a 2 week-old breastfed infant by maternal use of iodoform gauze for a perirectal abscess. The initial newborn thyroid screen was normal. Low levels of thyroid hormone were discovered during a routine second newborn screen.

View Article and Find Full Text PDF

Objectives: To compare immediate countershocks (defibrillation 1st) with precountershock cardiopulmonary resuscitation (CPR 1st) for prolonged ventricular fibrillation (VF).

Design: Randomized, controlled trial.

Setting: University animal laboratory.

View Article and Find Full Text PDF

Epidermal growth factor and necrotizing enterocolitis.

Clin Perinatol

March 2004

Department of Pediatrics and Steele Memorial Children's Research Center, University of Arizona, 1501 N. Campbell Ave, P.O. Box 245073, Tucson, AZ 85724, USA.

As the number of extremely low-birth-weight infants increases,necrotizing enterocolitis remains a critical eminent problem. Supplementation of enteral feeds with biologically active substances normally present in breast milk, such as epidermal growth factor, seems to be a logical and safe way to reduce the incidence of intestinal inflammation and necrotizing enterocolitis. Continuing basic research and clinical studies are essential before epidermal growth factor can be introduced as an efficient therapeutic approach in the treatment of neonatal necrotizing enterocolitis.

View Article and Find Full Text PDF