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1.
BMC Med Educ ; 23(1): 668, 2023 Sep 14.
Article in English | MEDLINE | ID: mdl-37710200

ABSTRACT

BACKGROUND: Physician decision-making skills training is a priority to improve adoption of the cerebral palsy (CP) clinical guideline and, through this, lower the age of CP diagnosis. Clinical guideline implementation aims to improve physician practice, but evaluating meaningful change is complex. Limitations in the validity evidence of evaluation instruments impact the evidence base. Validity frameworks, such as Kane's, enable a targeted process to gather evidence for instrument scores, congruent to context and purpose. Yet, application of argument-based methodology to implementation validation is rare. Key-features examination methodology has established validity evidence supporting its use to measure decision-making skills, with potential to predict performance. We aimed to apply Kane's framework to evaluate a pilot key-features examination on physician decision-making in early CP diagnosis. METHODS: Following Kane's framework, we evaluated evidence across inferences of scoring, generalisation, extrapolation and implications in a study design describing the development and pilot of a CP diagnosis key-features examination for practising physicians. If found to be valid, we proposed to use the key-feature scores as an outcome measure of decision-making post education intervention to expedite CP diagnosis and to correlate with real-world performance data to predict physician practice. RESULTS: Supporting evidence for acceptance of scoring inferences was achieved through examination development with an expert group (n = 10) and pilot results (n = 10): (1) high internal consistency (0.82); (2) acceptable mean item-discrimination (0.34); and (3) acceptable reliability of examination scorers (95.2% congruence). Decreased physician acceptance of examination time (70%) was identified as a threat and prioritised in case reduction processes. Partial acceptance of generalisation, extrapolation and implications inferences were defensible with: (1) accumulated development evidence following established key-features methodology; (2) high pilot acceptance for authenticity (90%); and (3) plausibility of assumptions of score correlation with population register data. CONCLUSIONS: Kane's approach is beneficial for prioritising sources of validity evidence alongside the iterative development of a key-features examination in the CP field. The validity argument supports scoring assumptions and use of scores as an outcome measure of physician decision-making for CP guideline education implementation interventions. Scoring evidence provides the foundation to direct future studies exploring association of key-feature scores with real-world performance.


Subject(s)
Cerebral Palsy , Physicians , Humans , Cerebral Palsy/diagnosis , Reproducibility of Results , Clinical Decision-Making , Educational Status
2.
Rozhl Chir ; 102(1): 11-16, 2023.
Article in English | MEDLINE | ID: mdl-36809889

ABSTRACT

INTRODUCTION: Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disease that leads to chronic renal failure in about half of patients. It is a multisystemic disease with a predominance of kidney involvement, which significantly worsens the patient's health. Controversial issues include the indication and the timing and technique of nephrectomy of native polycystic kidneys. METHODS: A retrospective observational study focused on the surgical aspects of patients with ADPKD who underwent native nephrectomy at our institution. The group included patients operated on in the period 1/1/2000-31/12/2020. A total of 115 patients with ADPKD were enrolled (14.7% of all transplant recipients). We evaluated the basic demographic data, type of surgery, indications and complications in this group. RESULTS: Native nephrectomy was performed in 68 out of a total of 115 (59%) patients. Unilateral nephrectomy was done in 22 (32%) patients and bilateral in 46 (68%). The most common indications were infections (42 patients, 36%), pain (31 patients, 27%), hematuria (14 patients, 12%), gastrointestinal reasons (1 patient, 1%), respiratory reasons (1 patient, 1%), obtaining a site for transplantation (17 patients, 15%) and suspected tumor (5 patients, 4%). CONCLUSION: Native nephrectomy is recommended in symptomatic kidneys, or in asymptomatic kidneys when it is necessary to obtain a place for kidney transplantation, and in kidneys where a tumor is suspected.


Subject(s)
Kidney Transplantation , Polycystic Kidney, Autosomal Dominant , Humans , Kidney Transplantation/methods , Polycystic Kidney, Autosomal Dominant/complications , Polycystic Kidney, Autosomal Dominant/pathology , Polycystic Kidney, Autosomal Dominant/surgery , Retrospective Studies , Kidney/pathology , Nephrectomy/methods
3.
J Neonatal Perinatal Med ; 15(1): 11-18, 2022.
Article in English | MEDLINE | ID: mdl-34219672

ABSTRACT

BACKGROUND: Perinatal stroke is one of the principal causes of cerebral palsy (CP) in preterm infants. Stroke in preterm infants is different from stroke in term infants, given the differences in brain maturation and the mechanisms of injury exclusive to the immature brain. We conducted a systematic review to explore the epidemiology and pathogenesis of periventricular hemorrhagic infarction (PVHI), perinatal arterial ischemic stroke (PAIS) and cerebral sinovenous thrombosis (CSVT) in preterm infants. METHODS: Studies were identified based on predefined study criteria from MEDLINE, EMBASE, SCOPUS and WEB OF SCIENCE electronic databases from 2000 -2019. Results were combined using descriptive statistics. RESULTS: Fourteen studies encompassed 546 stroke cases in preterm infants between 23 -36 weeks gestational ages and birth weights between 450 -3500 grams. Eighty percent (436/546) of the stroke cases were PVHI, 17%(93/546) were PAIS and 3%(17/546) were CSVT. Parietal PVHI was more common than temporal and frontal lobe PVHI. For PAIS, left middle cerebral artery (MCA) was more common than right MCA or cerebellar stroke. For CSVT partial or complete thrombosis in the transverse sinus was universal. All cases included multiple possible risk factors, but the data were discordant precluding aggregation within a meta-analysis. CONCLUSION: This systematic review confirms paucity of data regarding the etiology and the precise causal pathway of stroke in preterm infants. Moreover, the preterm infants unlike the term infants do not typically present with seizures. Hence high index of clinical suspicion and routine cUS will assist in the timely diagnosis and understanding of stroke in this population.


Subject(s)
Cerebral Palsy , Stroke , Brain , Female , Gestational Age , Humans , Infant , Infant, Newborn , Infant, Premature , Pregnancy , Stroke/epidemiology , Stroke/etiology
4.
Early Hum Dev ; 139: 104841, 2019 12.
Article in English | MEDLINE | ID: mdl-31607402

ABSTRACT

Conveying a diagnosis of a disability to the parents of young children is difficult both for the parent and the clinician, however there is an ethical and medical imperative to do so. However, the process and manner of disclosure needs to be done well. When communication between parent and clinicians fails, parental mental health can be adversely affected. This paper adapts and explains how to use the SPIKES protocol to deliver "bad news" about a developmental disability diagnosis with families of infants <12-months old, using cerebral palsy as an example. Next, the range of responses parents experience to the delivery of bad news from "watchful waiting" to "acceptance" are outlined and explained. The knowledge needs of parents range from causes and prognosis to treatments and outcomes. Using clinical scenarios of recently diagnosed infants, commonly asked questions and suggested answers are tabled.


Subject(s)
Disabled Children , Parents/psychology , Practice Guidelines as Topic , Attitude to Health , Cerebral Palsy , Child , Disability Evaluation , Humans , Physician-Patient Relations
5.
Rozhl Chir ; 98(8): 321-325, 2019.
Article in English | MEDLINE | ID: mdl-31462054

ABSTRACT

INTRODUCTION: Symptomatic lymphocele could impair the function of a graft kidney. The aim of our research was to conduct a five-year follow-up after symptomatic lymphocele therapy. METHODS: Overall 50 patients undergoing the therapy of symptomatic lymphocele were enrolled in the study cohort. Demographic data, renal failure causes, indication of therapy and lymphocele management were retrospectively evaluated. Laboratory tests were done to evaluate serum creatinine, total plasma protein and albumin levels. Survival rates of the patients and of the grafts were analysed using Kaplan-Meier curves. RESULTS: The mean age of the 50 patients (44% females, 56% males) was 51.5±11.8 years, and the time between kidney transplantation and symptomatic lymphocele diagnosis was 12.8±21.5 months. Average lymphocele diameter was 71±35 mm. Causes of the native kidney failure were: glomerulonephritis (34%), tubulointerstitial nephritis (30%), polycystosis (24%), diabetic nephropathy (10%) and nephrosclerosis (2%). The therapy indications were: serum creatinine elevation (44%), graft hydronephrosis (38%), serum creatinine elevation associated with hydronephrosis (8%), infection associated with hydronephrosis (6%) and infection (4%). The lymphocele was managed by: open surgical intraperitoneal drainage (40%), percutaneous aspiration (26%), percutaneous long-term drainage (18%) and laparoscopic intraperitoneal drainage (16%). Mean serum creatinine levels at the time of the therapy and 60 months later were 231 µmol/L and 172 µmol/L, respectively; total plasma protein levels were 59 g/L and 69 g/L, respectively; albumin plasma levels were 36 g/L and 43 g/L, respectively. The five-year patient survival rate was 86% and the graft survival rate was 66%. CONCLUSION: Adequate management of symptomatic lymphocele stabilizes the graft function. If the post-transplant lymphocele is indicated for therapy, the therapy should be applied as soon as possible to prevent fibrous changes in the surrounding tissues. No patient death or graft loss had any direct relationship with lymphocele management.


Subject(s)
Kidney Transplantation , Lymphocele , Adult , Drainage , Female , Follow-Up Studies , Humans , Lymphocele/etiology , Lymphocele/therapy , Male , Middle Aged , Retrospective Studies
6.
J Phys Chem A ; 122(8): 2079-2085, 2018 Mar 01.
Article in English | MEDLINE | ID: mdl-29384676

ABSTRACT

In this work, the study was performed with 37 gas-phase conformers of biotin and two biologically active conformers of biotin in the ligand-receptor complexes with astavidin and streptavidin. The ionization energies and photoelectron spectra of conformers were calculated by two methods: the general-R symmetry-adapted cluster-configuration interaction (general-R-SAC-CI) method and the outer-valence Green's function (OVGF) method. The photoelectron spectrum of each conformer was calculated using basis set D95 (df,pd) for both methods. The simulated photoelectron spectra of free molecules and bioactive conformers calculated by the two methods were compared. Natural bonding orbital (NBO) calculations were also performed for the assignment of ionization bands of each conformer. NBO calculation indicated that the first to five ionization bands correspond to ionizations from orbitals localized in the two rings. The most important point about the ionization of all conformers is that the removal of an electron from the σ-bonding orbital (C-S) takes place above 10.0 eV.

7.
Eur J Pain ; 22(4): 716-727, 2018 04.
Article in English | MEDLINE | ID: mdl-29194912

ABSTRACT

OBJECTIVE: To analyse the frequency of nonrecreational prescription analgesic sharing, associated factors and differences between lenders and borrowers. METHODS: A cross-sectional study was conducted in 10 outpatient family medicine practices in Croatia amongst 1000 patients to whom their physicians have prescribed analgesics at least once in their lives. A questionnaire was used to collect data about patients' pain intensity, prescription analgesic sharing habits, factors associated with this behaviour, perception of risks associated with the conduct and demographic data. Logistic regression was conducted to analyse independent factors associated with lending and borrowing prescription analgesics. RESULTS: We found that 61% of patients in family medicine practices engage in sharing prescription analgesics, whether it was lending (42%) and/or borrowing (54%). Independent predictors of lending prescription analgesics were as follows: history of sharing prescription medication other than analgesics, providing information regarding the medication alongside the prescription medication itself, not reading package insert that accompanies medication, subjective perception of personal health and decreased awareness of personal harm associated with prescription analgesic sharing. Independent predictors of prescription analgesic borrowing were as follows: younger age, communicating details regarding the medication that was given, scanning of package insert accompanying the medication, biased subjective perception of personal health and perceiving alternative medicine as a safer option over conventional medicine. CONCLUSIONS: Sharing prescription analgesics is highly prevalent amongst patients in family medicine. Healthcare providers should remain alert by routinely questioning patients regarding such behaviours. Preventive interventions should be conceived and established. SIGNIFICANCE: Sharing of prescription analgesics is a highly prevalent behaviour amongst pain patients, and there exist independent factors associated with such conduct. This information can be useful in the design of interventions aimed at mitigating analgesic sharing behaviour in the future.


Subject(s)
Analgesics/therapeutic use , Family Practice , Pain/drug therapy , Prescription Drugs/therapeutic use , Adult , Aged , Cross-Sectional Studies , Drug Prescriptions , Female , Humans , Male , Middle Aged
8.
Philos Trans A Math Phys Eng Sci ; 375(2093)2017 May 13.
Article in English | MEDLINE | ID: mdl-28373383

ABSTRACT

The complexity of fracture-induced segmentation in elastically constrained cohesive (fragile) systems originates from the presence of competing interactions. The role of discreteness in such phenomena is of interest in a variety of fields, from hierarchical self-assembly to developmental morphogenesis. In this paper, we study the analytically solvable example of segmentation in a breakable mass-spring chain elastically linked to a deformable lattice structure. We explicitly construct the complete set of local minima of the energy in this prototypical problem and identify among them the states corresponding to the global energy minima. We show that, even in the continuum limit, the dependence of the segmentation topology on the stretching/pre-stress parameter in this problem takes the form of a devil's type staircase. The peculiar nature of this staircase, characterized by locking in rational microstructures, is of particular importance for biological applications, where its structure may serve as an explanation of the robustness of stress-driven segmentation.This article is part of the themed issue 'Patterning through instabilities in complex media: theory and applications.'

9.
BMJ Open ; 6(10): e012924, 2016 10 24.
Article in English | MEDLINE | ID: mdl-27798026

ABSTRACT

OBJECTIVES: To examine the funding for cerebral palsy (CP) research in Australia, as compared with the National Institutes of Health (NIH). DESIGN: Observational study. SETTING: For Australia, philanthropic funding from Cerebral Palsy Alliance Research Foundation (CPARF) (2005-2015) was compared with National Health and Medical Research Council (NHMRC, 2000-2015) and Australian Research Council (ARC, 2004-2015) and CPARF and NHMRC funding were compared with NIH funding (USA). PARTICIPANTS: Cerebral Palsy researchers funded by CPARF, NHMRC or NIH. RESULTS: Over 10 years, total CPARF philanthropic funding was $21.9 million, including people, infrastructure, strategic and project support. As competitive grants, CPARF funded $11.1 million, NHMRC funded $53.5 million and Australian Research Council funded $1.5 million. CPARF, NHMRC and NIH funding has increased in real terms, but only the NIH statistically significantly increased in real terms (mean annual increase US$4.9 million per year, 95% CI 3.6 to 6.2, p<0.001). The NHMRC budget allocated to CP research remained steady over time at 0.5%. A network analysis indicated the relatively small number of CP researchers in Australia is mostly connected through CPARF or NHMRC funding. CONCLUSIONS: Funding for CP research from the Australian government schemes has stabilised and CP researchers rely on philanthropic funding to fill this gap. In comparison, the NIH is funding a larger number of CP researchers and their funding pattern is consistently increasing.


Subject(s)
Biomedical Research/economics , Cerebral Palsy , Financing, Organized , Research Support as Topic , Australia , Financing, Organized/trends , Humans , Research Support as Topic/trends , United States
10.
Pflugers Arch ; 468(11-12): 1865-1875, 2016 11.
Article in English | MEDLINE | ID: mdl-27752766

ABSTRACT

In the recent decades, ion channels became the focus of cancer biologists, as many channels are overexpressed in tumour tissue and functionally they are linked to abnormal cell behaviour with processes including apoptosis, chemo- and radioresistance, proliferation and migration. KCa3.1 is a Ca2+-activated K+ channel that plays a central role in tumour progression in many cancer types. Therefore, the aim of the present study was to investigate KCa3.1 expression in pancreatic cancer cells and assess possible implications to disease progression. Using qPCR technique, we found abundant expression of KCa3.1 in pancreatic cancer cell lines. Patch clamp measurements on MiaPaCa-2 cells revealed a Ca2+-activated K+ current that matched biophysical characteristics as described for KCa3.1. Moreover, the current was sensitive to the commonly used channel modulators TRAM-34, clotrimazole and DC-EBIO, and it was abolished following transient gene knockdown of KCa3.1. We utilized both pharmacology and RNAi to assess a possible role of the channel in tumour cell behaviour. We found that the channel supported MiaPaCa-2 cell proliferation. Using RNAi protocols, we also identified KCa3.1 as important entity in cell invasion. However, TRAM-34 had unexpected stimulatory effects on cell migration and invasion estimated in various assays. Moreover, TRAM-34 increased intracellular Ca2+. In conclusion, we found prominent functional expression of KCa3.1 in pancreatic cancer cells. We provide evidence that the channel has a key role in cell proliferation and for the first time identify KCa3.1 as important entity in PDAC cell migration. We further reveal anomalous effects of TRAM-34.


Subject(s)
Adenocarcinoma/metabolism , Cell Movement/drug effects , Cell Proliferation/drug effects , Intermediate-Conductance Calcium-Activated Potassium Channels/metabolism , Pancreatic Neoplasms/metabolism , Potassium Channel Blockers/pharmacology , Pyrazoles/pharmacology , Action Potentials , Benzimidazoles/pharmacology , Calcium/metabolism , Cell Line, Tumor , Clotrimazole/pharmacology , Humans , Intermediate-Conductance Calcium-Activated Potassium Channels/antagonists & inhibitors , Intermediate-Conductance Calcium-Activated Potassium Channels/genetics
11.
Eur Biophys J ; 45(7): 749-763, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27652669

ABSTRACT

The altered expression and/or activity of ion channels and transporters (transportome) have been associated with malignant behavior of cancer cells and were proposed to be a hallmark of cancer. However, the impact of altered transportome in epithelial cancers, such as pancreatic ductal adenocarcinoma (PDAC), as well as its pathophysiological consequences, still remains unclear. Here, we report the in silico analysis of 840 transportome genes in PDAC patients' tissues. Our study was focused on the transportome changes and their correlation with functional and behavioral responses in PDAC tumor and stromal compartments. The dysregulated gene expression datasets were filtered using a cut-off of fold-change values ≤-2 or ≥2 (adjusted p value ≤0.05). The dysregulated transportome genes were clearly associated with impaired physiological secretory mechanisms and/or pH regulation, control of cell volume, and cell polarity. Additionally, some down-regulated transportome genes were found to be closely linked to epithelial cell differentiation. Furthermore, the observed decrease in genes coding for calcium and chloride transport might be a mechanism for evasion of apoptosis. In conclusion, the current work provides a comprehensive overview of the altered transportome expression and its association with predicted PDAC malignancy with special focus on the epithelial compartment.


Subject(s)
Adenocarcinoma/metabolism , Computational Biology , Computer Simulation , Gene Expression Profiling , Ion Channels/genetics , Ion Channels/metabolism , Pancreatic Neoplasms/metabolism , Adenocarcinoma/genetics , Adenocarcinoma/pathology , Epithelium/metabolism , Humans , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , Tumor Microenvironment
12.
Vestn Oftalmol ; 132(1): 57-62, 2016.
Article in Russian | MEDLINE | ID: mdl-27030436

ABSTRACT

AIM: to perform comparative evaluation of intra- and postoperative clinical RESULTS in patients with complicated cataracts (grade I-II lens subluxation, pseudoexfoliation syndrome, or surgically treated glaucoma) undergoing either standard or femtosecond laser-assisted phacoemulsification. MATERIAL AND METHODS: A total of 197 patients (245 eyes) aged 32-85 years (58.5 years on average) with complicated cataracts were divided into two groups by the technique used for phacoemulsification. Group 1 (main group, 120 eyes of 105 patients) underwent femtosecond laser-assisted phacoemulsification. Group 2 (controls, 125 eyes of 92 patients) received standard procedures. Subjective and objective measures of ocular structure and function were evaluated in 1, 3, and 7 days and 1 month after the surgery. RESULTS: In the femtosecond laser-assisted group, all lenses were well-centered in the capsular bag as documented by ultrasound biomicroscopy. During the whole follow-up period the studied parameters were stable. No dislocations occurred. In group 2 (standard phaco), all parameters demonstrated high changeability over the follow-up period. CONCLUSION: The improved technique of femtosecond laser-assisted phacoemulsification offers many advantages to surgical management of complicated cataracts. Not only does it allow to reduce ultrasound time, but also to perform precise capsulorhexis with preset parameters, decrease intra- and postoperative complications rates, and improve refraction outcomes in such patients.

13.
Pflugers Arch ; 468(7): 1171-1181, 2016 07.
Article in English | MEDLINE | ID: mdl-26965147

ABSTRACT

Adenosine modulates a wide variety of biological processes via adenosine receptors. In the exocrine pancreas, adenosine regulates transepithelial anion secretion in duct cells and is considered to play a role in acini-to-duct signaling. To identify the functional adenosine receptors and Cl(-) channels important for anion secretion, we herein performed experiments on Capan-1, a human pancreatic duct cell line, using open-circuit Ussing chamber and gramicidin-perforated patch-clamp techniques. The luminal addition of adenosine increased the negative transepithelial potential difference (V te) in Capan-1 monolayers with a half-maximal effective concentration value of approximately 10 µM, which corresponded to the value obtained on whole-cell Cl(-) currents in Capan-1 single cells. The effects of adenosine on V te, an equivalent short-circuit current (I sc), and whole-cell Cl(-) currents were inhibited by CFTRinh-172, a cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel inhibitor. The adenosine A2B receptor agonist, BAY 60-6583, increased I sc and whole-cell Cl(-) currents through CFTR Cl(-) channels, whereas the A2A receptor agonist, CGS 21680, had negligible effects. The A2B receptor antagonist, PSB 603, inhibited the response of I sc to adenosine. Immunohistochemical analysis showed that the A2A and A2B receptors colocalized with Ezrin in the luminal membranes of Capan-1 monolayers and in rat pancreatic ducts. Adenosine elicited the whole-cell Cl(-) currents in guinea pig duct cells. These results demonstrate that luminal adenosine regulates anion secretion by activating CFTR Cl(-) channels via adenosine A2B receptors on the luminal membranes of Capan-1 cells. The present study endorses that purinergic signaling is important in the regulation of pancreatic secretion.


Subject(s)
Anions/metabolism , Epithelial Cells/metabolism , Pancreatic Ducts/metabolism , Receptor, Adenosine A2B/metabolism , Adenosine/analogs & derivatives , Adenosine/pharmacology , Aminopyridines/pharmacology , Animals , Cell Line , Chlorides/metabolism , Cystic Fibrosis Transmembrane Conductance Regulator/metabolism , Epithelial Cells/drug effects , Female , Guinea Pigs , Humans , Male , Membrane Potentials/drug effects , Pancreatic Ducts/drug effects , Phenethylamines/pharmacology , Rats , Rats, Wistar , Uridine/pharmacology
14.
Purinergic Signal ; 11(4): 533-50, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26431833

ABSTRACT

Extracellular adenosine triphosphate (ATP) regulates pancreatic duct function via P2Y and P2X receptors. It is well known that ATP is released from upstream pancreatic acinar cells. The ATP homeostasis in pancreatic ducts, which secrete bicarbonate-rich fluid, has not yet been examined. First, our aim was to reveal whether pancreatic duct cells release ATP locally and whether they enzymatically modify extracellular nucleotides/sides. Second, we wished to explore which physiological and pathophysiological factors may be important in these processes. Using a human pancreatic duct cell line, Capan-1, and online luminescence measurement, we detected fast ATP release in response to pH changes, bile acid, mechanical stress and hypo-osmotic stress. ATP release following hypo-osmotic stress was sensitive to drugs affecting exocytosis, pannexin-1, connexins, maxi-anion channels and transient receptor potential cation channel subfamily V member 4 (TRPV4) channels, and corresponding transcripts were expressed in duct cells. Direct stimulation of intracellular Ca(2+) and cAMP signalling and ethanol application had negligible effects on ATP release. The released ATP was sequentially dephosphorylated through ecto-nucleoside triphosphate diphosphohydrolase (NTPDase2) and ecto-5'-nucleotidase/CD73 reactions, with respective generation of adenosine diphosphate (ADP) and adenosine and their maintenance in the extracellular medium at basal levels. In addition, Capan-1 cells express counteracting adenylate kinase (AK1) and nucleoside diphosphate kinase (NDPK) enzymes (NME1, 2), which contribute to metabolism and regeneration of extracellular ATP and other nucleotides (ADP, uridine diphosphate (UDP) and uridine triphosphate (UTP)). In conclusion, we illustrate a complex regulation of extracellular purine homeostasis in a pancreatic duct cell model involving: ATP release by several mechanisms and subsequent nucleotide breakdown and ATP regeneration via counteracting nucleotide-inactivating and nucleotide-phosphorylating ecto-enzymes. We suggest that extracellular ATP homeostasis in pancreatic ducts may be important in pancreas physiology and potentially in pancreas pathophysiology.


Subject(s)
Adenosine Triphosphate/metabolism , Pancreas, Exocrine/metabolism , Pancreatic Ducts/metabolism , Adenosine/metabolism , Adenosine Diphosphate/metabolism , Adenosine Triphosphate/biosynthesis , Bile Acids and Salts/metabolism , Cell Line , Humans , Hydrogen-Ion Concentration , L-Lactate Dehydrogenase/metabolism , Osmolar Concentration , Pancreas, Exocrine/cytology , Pancreatic Ducts/cytology , Receptors, Purinergic P2X/metabolism , Receptors, Purinergic P2Y/metabolism , Stress, Physiological , Uridine Diphosphate/analogs & derivatives , Uridine Diphosphate/pharmacology , Uridine Triphosphate/analogs & derivatives , Uridine Triphosphate/pharmacology
15.
Pflugers Arch ; 467(7): 1495-1508, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25163766

ABSTRACT

Pancreatic ductal adenocarcinoma (PDAC) has one of the worst survival rates of all cancers. ANO1 (TMEM16A) is a recently identified Ca(2+)-activated Cl(-) channel (CaCC) that is upregulated in several tumors. Although ANO1 was subject to extensive studies in the recent years, its pathophysiological function has only been poorly understood. The aim of the present study is to establish the significance of ANO1 in PDAC behavior and demarcate its roles in PDAC from those of the volume-regulated anion channel (VRAC). We performed qPCR and Western blot measurements on different PDAC cell lines (Panc-1, Mia PaCa 2, Capan-1, AsPC-1, BxPC-3) and compared the results to those obtained in a human pancreatic ductal epithelium (HPDE) cell line. All cancer cell lines showed an upregulation of ANO1 on mRNA and protein levels. Whole-cell patch-clamp recordings identified large Ca(2+) and voltage-dependent Cl(-) currents in PDAC cells. Using siRNA knockdown of ANO1 and three ANO1 inhibitors (T16Ainh-A01, CaCCinh-A01, and NS3728), we found that ANO1 is the main constituent of CaCC current in PDAC cells. We further characterized these three inhibitors and found that they had unspecific effects on the free intracellular calcium concentration. Functional studies on PDAC behavior showed that surprisingly inhibition of ANO1 did not influence cellular proliferation. On the other hand, we found ANO1 channel to be pivotal in PDAC cell migration as assessed in wound healing experiments.


Subject(s)
Adenocarcinoma/metabolism , Chloride Channels/metabolism , Neoplasm Proteins/metabolism , Pancreatic Neoplasms/metabolism , Anoctamin-1 , Calcium/metabolism , Case-Control Studies , Cell Line, Tumor , Cell Movement , Chloride Channels/antagonists & inhibitors , Chloride Channels/genetics , Chlorides/metabolism , Humans , Neoplasm Proteins/antagonists & inhibitors , Neoplasm Proteins/genetics , RNA, Messenger/genetics , RNA, Messenger/metabolism , Up-Regulation
16.
Purinergic Signal ; 10(3): 431-40, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24488439

ABSTRACT

ATP is released from cells in response to various stimuli. Our previous studies on pancreas indicated that pancreatic acini could be major stores of secreted ATP. In the present study, our aim was to establish the role of the vesicular nucleotide transporter (VNUT), SLC17A9, in storage and release of ATP. Freshly prepared acini from mice and AR42J rat acinar cells were used in this study. We illustrate that in AR42J cells, quinacrine (an ATP store marker) and Bodipy ATP (a fluorescent ATP analog) co-localized with VNUT-mCherry to vesicles/granules. Furthermore, in acini and AR42J cells, a marker of the zymogen granule membranes, Rab3D, and VNUT co-localized. Dexamethasone treatment of AR42J cells promoted formation of acinar structures, paralleled by increased amylase and VNUT expression, and increased ATP release in response to cholinergic stimulation. Mechanical stimulus (pressure) and cell swelling also induced ATP release, but this was not influenced by dexamethasone, most likely indicating different non-zymogen-related release mechanism. In conclusion, we propose that VNUT-dependent ATP release pathway is associated with agonist-induced secretion process and downstream purinergic signalling in pancreatic ducts.


Subject(s)
Acinar Cells/metabolism , Adenosine Triphosphate/metabolism , Nucleotide Transport Proteins/physiology , Pancreas/metabolism , Animals , Cell Line , Female , Mice , Mice, Inbred C57BL , Rats
18.
Acta Physiol (Oxf) ; 207(3): 503-15, 2013 Mar.
Article in English | MEDLINE | ID: mdl-22805606

ABSTRACT

AIM: A number of K(+) channels are regulated by small, fast changes in cell volume. The mechanisms underlying cell volume sensitivity are not known, but one possible mechanism could be purinergic signalling. Volume activated ATP release could trigger signalling pathways that subsequently lead to ion channel stimulation and cell volume back-regulation. Our aim was to investigate whether volume sensitivity of the voltage-gated K(+) channel, KCNQ1, is dependent on ATP release and regulation by purinergic signalling. METHODS: We used Xenopus oocytes heterologously expressing human KCNQ1, KCNE1, water channels (AQP1) and P2Y2 receptors. ATP release was monitored by a luciferin-luciferase assay and ion channel conductance was recorded by two-electrode voltage clamp. RESULTS: The luminescence assay showed that oocytes released ATP in response to mechanical, hypoosmotic stimuli and hyperosmotic stimuli. Basal ATP release was approx. three times higher in the KCNQ1 + AQP1 and KCNQ1 injected oocytes compared to the non-injected ones. Exogenously added ATP (0.1 mm) did not have any substantial effect on volume-induced KCNQ1 currents. Nevertheless, apyrase decreased all currents by about 50%. Suramin inhibited about 23% of the KCNQ1 volume sensitivity. Expression of P2Y2 receptors stimulated endogenous Cl(-) channels, but it also led to 68% inhibition of the KCNQ1 currents. Adenosine (0.1 mm) also inhibited the KCNQ1 currents by about 56%. CONCLUSION: Xenopus oocytes release ATP in response to mechanical stimuli and cell volume changes. Purinergic P2 and P1 receptors confer some of the KCNQ1 channel volume sensitivity, although endogenous adenosine receptors and expressed P2Y2 receptors do so in the negative direction.


Subject(s)
Adenosine Triphosphate/metabolism , Adenosine/metabolism , Cell Size , KCNQ1 Potassium Channel/metabolism , Mechanotransduction, Cellular , Oocytes/metabolism , Receptors, Purinergic/metabolism , Animals , Aquaporin 1/genetics , Aquaporin 1/metabolism , Cell Size/drug effects , Genes, Reporter , Humans , Ion Channel Gating , KCNQ1 Potassium Channel/antagonists & inhibitors , KCNQ1 Potassium Channel/genetics , Mechanotransduction, Cellular/drug effects , Membrane Potentials , Osmotic Pressure , Patch-Clamp Techniques , Potassium Channels, Voltage-Gated/genetics , Potassium Channels, Voltage-Gated/metabolism , Purinergic Antagonists/pharmacology , Receptors, Purinergic/drug effects , Receptors, Purinergic/genetics , Receptors, Purinergic P2Y2/metabolism , Xenopus laevis
19.
J Endocrinol ; 213(2): 123-41, 2012 May.
Article in English | MEDLINE | ID: mdl-22396456

ABSTRACT

Pancreatic cells contain specialised stores for ATP. Purinergic receptors (P2 and P1) and ecto-nucleotidases are expressed in both endocrine and exocrine calls, as well as in stromal cells. The pancreas, especially the endocrine cells, were an early target for the actions of ATP. After the historical perspective of purinergic signalling in the pancreas, the focus of this review will be the physiological functions of purinergic signalling in the regulation of both endocrine and exocrine pancreas. Next, we will consider possible interaction between purinergic signalling and other regulatory systems and their relation to nutrient homeostasis and cell survival. The pancreas is an organ exhibiting several serious diseases - cystic fibrosis, pancreatitis, pancreatic cancer and diabetes - and some are associated with changes in life-style and are increasing in incidence. There is upcoming evidence for the role of purinergic signalling in the pathophysiology of the pancreas, and the new challenge is to understand how it is integrated with other pathological processes.


Subject(s)
Pancreas/physiology , Pancreas/physiopathology , Receptors, Purinergic/physiology , 5'-Nucleotidase/metabolism , Acinar Cells/physiology , Adenosine Triphosphate/physiology , Cystic Fibrosis/physiopathology , Diabetes Mellitus/physiopathology , Homeostasis , Humans , Insulin-Secreting Cells/physiology , Pancreas/innervation , Pancreas, Exocrine/physiopathology , Pancreatic Neoplasms/physiopathology , Pancreatic Stellate Cells/physiology , Pancreatitis/physiopathology , Signal Transduction/physiology
20.
J Int Med Res ; 39(2): 629-36, 2011.
Article in English | MEDLINE | ID: mdl-21672368

ABSTRACT

This study evaluated inflammatory, coagulation and microvascular responses to a continuous 24-h work day in 13 healthy intensive care physicians. Inflammatory markers (interleukin [IL]-2, IL-6, IL-10, tumour necrosis factor-α, matrix metalloproteinase [MMP]-9 and adiponectin), adhesion molecules (vascular cellular adhesion molecule-1 and intercellular adhesion molecule-1 [ICAM-1]), coagulation parameters (thrombin-anti thrombin, von Willebrand factor and tissue factor) and sublingual micro circulation were assessed before and after a 24-h work shift. The 24-h work shift had no effect on inflammatory markers and ICAM-1. Direct visualization of micro-circulation did not reveal stress-related perfusion abnormalities. A 24-h work shift in the intensive care unit was associated with significantly increased plasma levels of tissue factor - a potentially important mechanism linking acute job strain, haemostasis and atherosclerosis. The long-term consequences warrant further evaluation.


Subject(s)
Biological Phenomena , Health Personnel , Health , Intensive Care Units , Stress, Physiological , Adult , Biomarkers/blood , Endothelium, Vascular/physiopathology , Female , Hemodynamics , Hemostasis , Humans , Inflammation Mediators/metabolism , Male , Microcirculation , Thromboplastin/metabolism , Time Factors
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