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The quality of care delivered to residents in long-term care in Australia: an indicator-based review of resident records (CareTrack Aged study). BMC Med 2024; 22:22. [PMID: 38254113 PMCID: PMC10804560 DOI: 10.1186/s12916-023-03224-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 12/12/2023] [Indexed: 01/24/2024] Open
Abstract
BACKGROUND This study estimated the prevalence of evidence-based care received by a population-based sample of Australian residents in long-term care (LTC) aged ≥ 65 years in 2021, measured by adherence to clinical practice guideline (CPG) recommendations. METHODS Sixteen conditions/processes of care amendable to estimating evidence-based care at a population level were identified from prevalence data and CPGs. Candidate recommendations (n = 5609) were extracted from 139 CPGs which were converted to indicators. National experts in each condition rated the indicators via the RAND-UCLA Delphi process. For the 16 conditions, 236 evidence-based care indicators were ratified. A multi-stage sampling of LTC facilities and residents was undertaken. Trained aged-care nurses then undertook manual structured record reviews of care delivered between 1 March and 31 May 2021 (our record review period) to assess adherence with the indicators. RESULTS Care received by 294 residents with 27,585 care encounters in 25 LTC facilities was evaluated. Residents received care for one to thirteen separate clinical conditions/processes of care (median = 10, mean = 9.7). Adherence to evidence-based care indicators was estimated at 53.2% (95% CI: 48.6, 57.7) ranging from a high of 81.3% (95% CI: 75.6, 86.3) for Bladder and Bowel to a low of 12.2% (95% CI: 1.6, 36.8) for Depression. Six conditions (skin integrity, end-of-life care, infection, sleep, medication, and depression) had less than 50% adherence with indicators. CONCLUSIONS This is the first study of adherence to evidence-based care for people in LTC using multiple conditions and a standardised method. Vulnerable older people are not receiving evidence-based care for many physical problems, nor care to support their mental health nor for end-of-life care. The six conditions in which adherence with indicators was less than 50% could be the focus of improvement efforts.
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Unsafe care in residential settings for older adults: a content analysis of accreditation reports. Int J Qual Health Care 2023; 35:mzad085. [PMID: 37795694 PMCID: PMC10654691 DOI: 10.1093/intqhc/mzad085] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 09/20/2023] [Accepted: 09/29/2023] [Indexed: 10/06/2023] Open
Abstract
Residents of aged care services can experience safety incidents resulting in preventable serious harm. Accreditation is a commonly used strategy to improve the quality of care; however, narrative information within accreditation reports is not generally analysed as a source of safety information to inform learning. In Australia, the Aged Care Quality and Safety Commission (ACQSC), the sector regulator, undertakes over 500 accreditation assessments of residential aged care services against eight national standards every year. From these assessments, the Aged Care Quality and Safety Commission generates detailed Site Audit Reports. In over one-third (37%) of Site Audit Reports, standards relating to Personal and Clinical Care (Standard 3) are not being met. The aim of this study was to identify the types of resident Safety Risks that relate to Personal and Clinical Care Standards not being met during accreditation or re-accreditation. These data could inform priority setting at policy, regulatory, and service levels. An analytical framework was developed based on the World Health Organization's International Classification for Patient Safety and other fields including Clinical Issue (the issue related to the incident impacting the resident, e.g. wound/skin or pain). Information relating to safety incidents in the Site Audit Reports was extracted, and a content analysis undertaken using the analytical framework. Clinical Issue and the International Classification for Patient Safety-based classification were combined to describe a clinically intuitive category ('Safety Risks') to describe ways in which residents could experience unsafe care, e.g. diagnosis/assessment of pain. The resulting data were descriptively analysed. The analysis included 65 Site Audit Reports that were undertaken between September 2020 and March 2021. There were 2267 incidents identified and classified into 274 types of resident Safety Risks. The 12 most frequently occurring Safety Risks account for only 32.3% of all incidents. Relatively frequently occurring Safety Risks were organisation management of infection control; diagnosis/assessment of pain, restraint, resident behaviours, and falls; and multiple stages of wounds/skin management, e.g. diagnosis/assessment, documentation, treatment, and deterioration. The analysis has shown that accreditation reports contain valuable data that may inform prioritization of resident Safety Risks in the Australian residential aged care sector. A large number of low-frequency resident Safety Risks were detected in the accreditation reports. To address these, organizations may use implementation science approaches to facilitate evidence-based strategies to improve the quality of care delivered to residents. Improving the aged care workforces' clinical skills base may address some of the Safety Risks associated with diagnosis/assessment and wound management.
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Comparing rates of adverse events detected in incident reporting and the Global Trigger Tool: a systematic review. Int J Qual Health Care 2023; 35:mzad056. [PMID: 37440353 PMCID: PMC10367579 DOI: 10.1093/intqhc/mzad056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 06/21/2023] [Accepted: 07/11/2023] [Indexed: 07/15/2023] Open
Abstract
Many hospitals continue to use incident reporting systems (IRSs) as their primary patient safety data source. The information IRSs collect on the frequency of harm to patients [adverse events (AEs)] is generally of poor quality, and some incident types (e.g. diagnostic errors) are under-reported. Other methods of collecting patient safety information using medical record review, such as the Global Trigger Tool (GTT), have been developed. The aim of this study was to undertake a systematic review to empirically quantify the gap between the percentage of AEs detected using the GTT to those that are also detected via IRSs. The review was conducted in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Studies published in English, which collected AE data using the GTT and IRSs, were included. In total, 14 studies met the inclusion criteria. All studies were undertaken in hospitals and were published between 2006 and 2022. The studies were conducted in six countries, mainly in the USA (nine studies). Studies reviewed 22 589 medical records using the GTT across 107 institutions finding 7166 AEs. The percentage of AEs detected using the GTT that were also detected in corresponding IRSs ranged from 0% to 37.4% with an average of 7.0% (SD 9.1; median 3.9 and IQR 5.2). Twelve of the fourteen studies found <10% of the AEs detected using the GTT were also found in corresponding IRSs. The >10-fold gap between the detection rates of the GTT and IRSs is strong evidence that the rate of AEs collected in IRSs in hospitals should not be used to measure or as a proxy for the level of safety of a hospital. IRSs should be recognized for their strengths which are to detect rare, serious, and new incident types and to enable analysis of contributing and contextual factors to develop preventive and corrective strategies. Health systems should use multiple patient safety data sources to prioritize interventions and promote a cycle of action and improvement based on data rather than merely just collecting and analysing information.
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Designing Clinical Indicators for Common Residential Aged Care Conditions and Processes of Care: The CareTrack Aged Development and Validation Study. Int J Qual Health Care 2022; 34:6571667. [PMID: 35445264 DOI: 10.1093/intqhc/mzac033] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 02/27/2022] [Accepted: 04/20/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND People who live in aged care homes have high rates of illness and frailty. Providing evidence-based care to this population is vital to ensure the highest possible quality of life. This study (CareTrack Aged, CT Aged) aimed to develop a comprehensive set of clinical indicators for guideline-adherent, appropriate care of commonly managed conditions and processes of care in aged care. METHODS Indicators were formulated from recommendations found through systematic searches of Australian and international clinical practice guidelines (CPGs). Experts reviewed the indicators using a multi-round modified Delphi process to develop consensus on what constitutes appropriate care. RESULTS From 139 CPGs, 5,609 recommendations were used to draft 630 indicators. Clinical experts (n=41) reviewed the indicators over two rounds. A final set of 236 indicators resulted, mapped to 16 conditions and processes of care. The conditions and processes were admission assessment; bladder and bowel problems; cognitive impairment; depression; dysphagia and aspiration; end of life/palliative care; hearing and vision; infection; medication; mobility and falls; nutrition and hydration; oral and dental care; pain; restraint use; skin integrity; and sleep. CONCLUSIONS The suite of CT Aged clinical indicators can be used for research, assessment of quality of care in individual facilities and across organisations to guide improvement, and to supplement regulation or accreditation of the aged care sector. They are a step forward for Australian and international aged care sectors, helping to improve transparency, so that the level of care delivered to aged care consumers can be rigorously monitored and continuously improved.
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Child and caregiver experiences and perceptions of asthma self-management. NPJ Prim Care Respir Med 2021; 31:42. [PMID: 34504105 PMCID: PMC8429661 DOI: 10.1038/s41533-021-00253-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 08/19/2021] [Indexed: 02/07/2023] Open
Abstract
Asthma is the most common chronic condition of childhood. Self-management is integral to good asthma control. This qualitative paper explores how children with asthma and their parents perceive asthma, their experience with asthma, and how they manage symptoms, preventions and medications within and outside the home. We undertook 15 focus groups with 41 school-aged (6-11 years) children with asthma and 38 parents. Parents and their children attended the same focus groups. We used thematic analysis to analyse the transcripts. Our findings show the impact asthma can have on children's social and emotional wellbeing and highlight how reliant school-aged children are on their parents to effectively manage their asthma. Parents reported being unsure when their child's symptoms warranted visiting their doctor or hospital. Schools were identified as a source of difficulty regarding asthma management; families reported that children may be self-conscious about their asthma and using their inhaler at school. School policies and teachers' lack of asthma knowledge were reported to exacerbate children's reluctance to use their inhaler at school. Our results have implications for the design and implementation of children's self-management interventions for their asthma, particularly when they are at school and away from their parents.
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Assessing the appropriateness of the management of gastro-oesophageal reflux in Australian children: a population-based sample survey. Sci Rep 2021; 11:7744. [PMID: 33833360 PMCID: PMC8032666 DOI: 10.1038/s41598-021-87369-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 03/25/2021] [Indexed: 11/23/2022] Open
Abstract
Gastro-oesophageal reflux (GOR) is a common physiological state in infants and young children, with gastro-oesophageal reflux disease (GORD) its pathological manifestation. Management of GOR/GORD requires elimination of possible underlying causes, parental reassurance, modification of feeding and symptom mitigation, monitoring, and referral to paediatricians if warning signs are present. Published clinical practice guidelines (CPGs) seek to support clinicians and improve management. This study aimed to measure the proportion of Australian GOR/GORD paediatric care that was in line with CPG recommendations. National and international CPGs for GOR/GORD were systematically identified and candidate indicators extracted; a Delphi process selected 32 indicators relevant to Australian paediatric care in 2012 and 2013. Medical records were identified in General Practices, the offices of general paediatricians, Emergency Departments and inpatient settings. Adherence to indicators was assessed by nine trained paediatric nurses undertaking retrospective medical record review. Medical records were reviewed in 115 healthcare sites; identifying 285 children, three-quarters aged < 1 year, who had 359 visits for management of GOR/GORD; 2250 eligible indicator assessments were performed. Estimated adherence rates are reported for 21 indicators with ≥ 25 assessments. Five indicators recommending differential diagnostic tests (e.g., urinalysis) for infants presenting with recurrent regurgitation and poor weight gain had ~ 10% adherence; conversely, avoidance of unrecommended tests (e.g., barium swallow and meal) was high (99.8% adherence: 95% CI 97.0-100). Avoidance of prescription of acid-suppression medication for infants at the first presentation was higher if they were healthy and thriving (86.9% adherence: 95% CI 86.0-96.8), intermediate if they had feeding refusal (73.1%: 95% CI 56.0-86.3) and lower if they presented with irritability and unexplained crying (58.8%: 95% CI 28.2-85.0). A guideline targeting Australian health professionals caring for infants and children with GOR/GORD is warranted, highlighting the importance of differential diagnostic testing and avoidance of acid-suppression medication in infants.
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Guideline adherence in the management of attention deficit hyperactivity disorder in children: An audit of selected medical records in three Australian states. PLoS One 2021; 16:e0245916. [PMID: 33556083 PMCID: PMC7869992 DOI: 10.1371/journal.pone.0245916] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 01/08/2021] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE To assess General Practitioner (GP) and pediatrician adherence to clinical practice guidelines (CPGs) for diagnosis, treatment and management of attention deficit hyperactivity disorder (ADHD). METHOD Medical records for 306 children aged ≤15 years from 46 GP clinics and 20 pediatric practices in Australia were reviewed against 34 indicators derived from CPG recommendations. At indicator level, adherence was estimated as the percentage of indicators with 'Yes' or 'No' responses for adherence, which were scored 'Yes'. This was done separately for GPs, pediatricians and overall; and weighted to adjust for sampling processes. RESULTS Adherence with guidelines was high at 83.6% (95% CI: 77.7-88.5) with pediatricians (90.1%; 95% CI: 73.0-98.1) higher than GPs (68.3%; 95% CI: 46.0-85.8; p = 0.02). Appropriate assessment for children presenting with signs or symptoms of ADHD was undertaken with 95.2% adherence (95% CI: 76.6-99.9), however ongoing reviews for children with ADHD prescribed stimulant medication was markedly lower for both pediatricians (51.1%; 95% CI: 9.6-91.4) and GPs (18.7%; 95% CI: 4.1-45.5). CONCLUSION Adherence to CPGs for ADHD by pediatricians was generally high. Adherence by GPs was lower across most domains; timely recognition of medication side effects is a particular area for improvement.
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Characterising the types of paediatric adverse events detected by the global trigger tool – CareTrack Kids. JOURNAL OF PATIENT SAFETY AND RISK MANAGEMENT 2020. [DOI: 10.1177/2516043520969329] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
IntroductionA common method of learning about adverse events (AEs) is by reviewing medical records using the global trigger tool (GTT). However, these studies generally report rates of harm. The aim of this study is to characterise paediatric AEs detected by the GTT using descriptive and qualitative approaches.MethodsMedical records of children aged 0–15 were reviewed for presence of harm using the GTT. Records from 2012–2013 were sampled from hospital inpatients, emergency departments, general practice and specialist paediatric practices in three Australian states. Nurses undertook a review of each record and if an AE was suspected a doctor performed a verification review of a summary created by the nurse. A qualitative content analysis was undertaken on the summary of verified AEs.ResultsA total of 232 AEs were detected from 6,689 records reviewed. Over four-fifths of the AEs (193/232, 83%) resulted in minor harm to the patient. Nearly half (112/232, 48%) related to medication/intravenous (IV) fluids. Of these, 83% (93/112) were adverse drug reactions. Problems with medical devices/equipment were the next most frequent with nearly two-thirds (32/51, 63%) of these related to intravenous devices. Problems associated with clinical processes/procedures comprise one in six AEs (38/232, 16%), of which diagnostic problems (12/38, 32%) and procedural complications (11/38, 29%) were the most frequent.ConclusionAdverse drug reactions and issues with IVs are frequently identified AEs reflecting their common use in paediatrics. The qualitative approach taken in this study allowed AE types to be characterised, which is a prerequisite for developing and prioritising improvements in practice.
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Reducing preventable harm to residents in aged care: A systems approach. Australas J Ageing 2020; 40:72-76. [PMID: 33006429 DOI: 10.1111/ajag.12861] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 08/30/2020] [Accepted: 09/02/2020] [Indexed: 11/30/2022]
Abstract
Residents in Australian aged care facilities can suffer serious preventable harm from incidents ('adverse events' (AEs)). An inadequate response to AEs by aged care facilities can compound distress to residents and their families/carers. Facilities have an obligation to respond to and investigate AEs involving residents, learn from them, and take action to reduce the chance of them reoccurring . Residential aged care facilities have a duty to create a culture where staff, residents and families/carers feel comfortable reporting AEs or complaints; there is adequate time and resources to manage AEs and complaints; and feedback is provided to staff, residents and their families/carers on the results of investigations into AEs/complaints. The Aged Care Quality and Safety Commission's role should encompass additional governance functions such as sharing results and lessons learnt from AEs, complaints and investigations across Australia, assuring the quality of investigations conducted by facilities, and undertaking national system-wide investigations.
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Guideline adherence in the management of head injury in Australian children: A population-based sample survey. PLoS One 2020; 15:e0228715. [PMID: 32045446 PMCID: PMC7012413 DOI: 10.1371/journal.pone.0228715] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 01/21/2020] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Head injuries in children are a common and potentially devastating presentation. The CareTrack Kids (CTK) study assessed care of Australian children aged 0-15 years, in 2012 and 2013, to evaluate the proportion in line with guideline-based indicators for 17 common conditions. Overall adherence to guideline-based recommended practice occurred 59.8% of care encounters (95% CI: 57.5-62.0), and 78.3% (95% CI: 75.1-81.2) for head injury. This paper presents results for head injury, at indicator level. METHODS A modified version of the RAND-UCLA method of indicator development was used. Indicators, measurable components of a standard or guideline, were developed from international and national guidelines relating to head injury in children and were ratified by clinical experts using a Delphi process. Paediatric nurses extracted data from medical records from general practitioners (GPs), emergency departments (EDs) and inpatient wards in Queensland, New South Wales and South Australia, for children under 15 years receiving care in 2012-13. Our purpose was to estimate the percentage adherent for each indicator. RESULTS The medical records of 629 children with head injury were examined. Fifty-one percent of children were under 5 years old, with more males (61%) than females. Thirty-eight indicators were assessed. Avoidance of nasotracheal airways (100%; 95% CI: 99.4-100) or nasogastric tubes (99.7%; 95% CI: 98.5-100) for children with a head injury had the highest adherence. Indicators relating to primary and secondary assessment of head injuries were mostly adhered to. However, adherence to other indicators was poor (e.g., documentation of the past history of children (e.g., presence or absence of seizures) before the injury; 29.9% (95% CI: 24.5-35.7)), and for others was difficult to estimate with confidence due to small sample sizes (e.g., Children with a head injury who were intubated had PaO2 above 80mm Hg; 56.0% (95% CI: 28.6-80.9)). Indicators guiding clinical decision making regarding the need for CT scan had insufficient data to justify reporting. CONCLUSION This study highlights that management of head injury in children mostly follows guidelines, but also flags some specific areas of inconsistency. Individual sites are encouraged to use these results to guide investigation of local practices and inform quality improvement endeavours.
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Assessing the adherence to guidelines in the management of croup in Australian children: a population-based sample survey. Int J Qual Health Care 2019; 31:759-767. [PMID: 31665290 DOI: 10.1093/intqhc/mzz088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 05/28/2019] [Accepted: 07/17/2019] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVE To determine the extent to which care received by Australian children presenting with croup is in agreement with Clinical Practice Guidelines (CPGs). DESIGN Retrospective population-based sample survey. Croup clinical indicators were derived from CPGs. DATA SOURCES/STUDY SETTING Medical records from three healthcare settings were sampled for selected visits in 2012 and 2013 in three Australian states. DATA COLLECTION Data were collected by nine experienced paediatric nurses, trained to assess eligibility for indicator assessment and adherence to CPGs. Surveyors undertook criterion-based medical record reviews using an electronic data collection tool. RESULTS Documented guideline adherence was lower for general practitioners (65.9%; 95% CI: 60.8-70.6) than emergency departments (91.1%; 95% CI: 89.5-92.5) and inpatient admissions (91.3%; 95% CI: 88.1-93.9). Overall adherence was very low for a bundle of 10 indicators related to assessment (4.5%; 95% CI: 2.4-7.6) but higher for a bundle of four indicators relating to the avoidance of inappropriate therapy (83.1%; 95% CI: 59.5-96.0). CONCLUSIONS Most visits for croup were characterized by appropriate treatment in all healthcare settings. However, most children had limited documented clinical assessments, and some had unnecessary tests or inappropriate therapy, which has potential quality and cost implications. Universal CPG and clinical assessment tools may increase clinical consistency.
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The quality of preventive care for pre-school aged children in Australian general practice. BMC Med 2019; 17:218. [PMID: 31805928 PMCID: PMC6896286 DOI: 10.1186/s12916-019-1455-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 10/28/2019] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Variable and poor care quality are important causes of preventable patient harm. Many patients receive less than recommended care, but the extent of the problem remains largely unknown. The CareTrack Kids (CTK) research programme sought to address this evidence gap by developing a set of indicators to measure the quality of care for common paediatric conditions. In this study, we focus on one clinical area, 'preventive care' for pre-school aged children. Our objectives were two-fold: (i) develop and validate preventive care quality indicators and (ii) apply them in general medical practice to measure adherence. METHODS Clinical experts (n = 6) developed indicator questions (IQs) from clinical practice guideline (CPG) recommendations using a multi-stage modified Delphi process, which were pilot tested in general practice. The medical records of Australian children (n = 976) from general practices (n = 80) in Queensland, New South Wales and South Australia identified as having a consultation for one of 17 CTK conditions of interest were retrospectively reviewed by trained paediatric nurses. Statistical analyses were performed to estimate percentage compliance and its 95% confidence intervals. RESULTS IQs (n = 43) and eight care 'bundles' were developed and validated. Care was delivered in line with the IQs in 43.3% of eligible healthcare encounters (95% CI 30.5-56.7). The bundles of care with the highest compliance were 'immunisation' (80.1%, 95% CI 65.7-90.4), 'anthropometric measurements' (52.7%, 95% CI 35.6-69.4) and 'nutrition assessments' (38.5%, 95% CI 24.3-54.3), and lowest for 'visual assessment' (17.9%, 95% CI 8.2-31.9), 'musculoskeletal examinations' (24.4%, 95% CI 13.1-39.1) and 'cardiovascular examinations' (30.9%, 95% CI 12.3-55.5). CONCLUSIONS This study is the first known attempt to develop specific preventive care quality indicators and measure their delivery to Australian children in general practice. Our findings that preventive care is not reliably delivered to all Australian children and that there is substantial variation in adherence with the IQs provide a starting point for clinicians, researchers and policy makers when considering how the gap between recommended and actual care may be narrowed. The findings may also help inform the development of specific improvement interventions, incentives and national standards.
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Assessing the quality of care for paediatric depression and anxiety in Australia: A population-based sample survey. Aust N Z J Psychiatry 2019; 53:1013-1025. [PMID: 31394909 DOI: 10.1177/0004867419866512] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE We examine the prevalence of quality care (as measured by adherence to recommendations in clinical practice guidelines) for Australian paediatric patients (⩽15 years) with depression and/or anxiety, using data from the CareTrack Kids study; a population-based study of the quality of healthcare practice in inpatient and ambulatory healthcare settings. METHODS A multistage stratified sample identified records of 6689 children. Of these, 156 records were identified for depression and 356 for anxiety. These were assessed for adherence to 15 depression and 13 anxiety indicators, respectively, using a review of medical records. RESULTS Adherence to assessment and management guidelines was low for both conditions: assessment bundle (depression = 33%, 95% confidence interval = [20, 48]; anxiety = 54%, 95% confidence interval = [43, 64] and depression management bundle = 35%, 95% confidence interval = [15, 60]). Across both conditions, the highest adherence was recorded for indicators that addressed prescription of medications (e.g. venlafaxine, 100%; benzodiazepines, 100%; selective serotonin reuptake inhibitor, 94% and antidepressants, 91%), while compliance was the lowest for ensuring children with depression had an emergency safety plan (44%), informing parents of the risks and benefits of prescribed anxiety medication (51%) and assessment for other causes (59% for depression; 68% for anxiety). CONCLUSION These findings suggest that strategies are needed to improve guideline adherence for mental health disorders in children and adolescents, particularly among general practitioners. Learning from these indicators could inform clinical prompts in electronic medical records, as well as links to additional information, to assist in decision-making and streamline work practices.
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Abstract
INTRODUCTION The aged population is increasing rapidly across the world and this is expected to continue. People living in residential aged care facilities (RACFs) represent amongst the sickest and frailest cohort of the aged population, with a high prevalence of chronic conditions and complex comorbidities. Given the vulnerability of RACF residents and the demands on the system, there is a need to determine the extent that care is delivered in line with best practice ('appropriate care') in RACFs. There is also a recognition that systems should provide care that optimises quality of life (QoL), which includes support for physical and psychological well-being, independence, social relationships, personal beliefs and a caring external environment. The aims of CareTrack Aged are to develop sets of indicators for appropriate care and processes of care for commonly managed conditions, and then assess the appropriateness of care delivered and QoL of residents in RACFs in Australia. METHODS AND ANALYSIS We will extract recommendations from clinical practice guidelines and, using expert review, convert these into sets of indicators for 15 common conditions and processes of care for people living in RACFs. We will recruit RACFs in three Australian states, and residents within these RACFs, using a stratified multistage sampling method. Experienced nurses, trained in the CareTrack Aged methods ('surveyors'), will review care records of recruited residents within a 1-month period in 2019 and 2020, and assess the care documented against the indicators of appropriate care. Surveyors will concurrently assess residents' QoL using validated questionnaires. ETHICS AND DISSEMINATION The study has been reviewed and approved by the Human Research Ethics Committee of Macquarie University (5201800386). The research findings will be published in international and national journals and disseminated through conferences and presentations to interested stakeholder groups, including consumers, national agencies, healthcare professionals, policymakers and researchers.
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Assessing appropriateness of paediatric asthma management: A population-based sample survey. Respirology 2019; 25:71-79. [PMID: 31220876 DOI: 10.1111/resp.13611] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 03/11/2019] [Accepted: 04/30/2019] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND OBJECTIVE We conducted a comprehensive assessment of guideline adherence in paediatric asthma care, including inpatient and ambulatory services, in Australia. METHODS National and international clinical practice guidelines (CPG) relating to asthma in children were searched and 39 medical record audit indicator questions were developed. Retrospective medical record review was conducted across hospital inpatient admissions, emergency department (ED) presentations, general practice (GP) and paediatrician consultations in three Australian states for children aged ≤15 years receiving care in 2012 and 2013. Eligibility of, and adherence to, indicators was assessed from medical records by nine experienced and purpose-trained paediatric nurses (surveyors). RESULTS Surveyors conducted 18 453 asthma indicator assessments across 1600 visits for 881 children in 129 locations. Overall, the adherence for asthma care across the 39 indicators was 58.1%, with 54.4% adherence at GP (95% CI: 46.0-62.5), 77.7% by paediatricians (95% CI: 40.5-97.0), 79.9% in ED (95% CI: 70.6-87.3) and 85.1% for inpatient care (95% CI: 76.7-91.5). For 14 acute asthma indicators, overall adherence was 56.3% (95% CI: 47.6-64.7). Lowest adherences were for recording all four types of vital signs in children aged >2 years presenting with asthma attack (15.1%, 95% CI: 8.7-23.7), and reviewing patients' compliance, inhaler technique and triggers prior to commencing a new drug therapy (20.5%, 95% CI: 10.1-34.8). CONCLUSION The study demonstrated differences between existing care and CPG recommendations for paediatric asthma care in Australia. Evidence-based interventions to improve adherence to CPG may help to standardize quality of paediatric asthma care and reduce variation of care.
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Assessing the appropriateness of the management of upper respiratory tract infection in Australian children: a population-based sample survey. BMJ Open 2019; 9:e026915. [PMID: 31092659 PMCID: PMC6530449 DOI: 10.1136/bmjopen-2018-026915] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVE To assess the proportion of Australian children aged 0-15 years that received care in line with clinical practice guidelines (CPGs) for upper respiratory tract infections (URTIs). DESIGN Retrospective medical record review using a multistage sampling strategy. SETTING General practices, hospital emergency departments and hospital inpatient service providers in three Australian states. PARTICIPANTS Children aged up to 15 years who received care for URTI in 2012 and 2013. PRIMARY AND SECONDARY OUTCOME MEASURES The primary assessment was estimated adherence with 14 indicators of appropriate care as documented in medical records. Indicators were extracted from national and international CPGs and ratified by experts. Secondary assessment was adherence to two bundles of indicators (diagnostic symptoms and medical history taking), where all indicators must be adherent for the bundle to be scored as adherent. RESULTS There were 1653 children with one or more assessments of URTI care to CPG adherence. Over half of the children were under 3 years of age, with roughly equal numbers of males and females. Three indicators had fewer than 25 visits so were not reported. Overall adherence ranged from 0.5% for 'documented advice around antibiotics' to 88.3% for 'documentation of medical history'. Adherence with Bundle A (documentation of all three definitive symptoms) was 43.1% (95% CI 32.8% to 54.0%) and Bundle B (documentation of all four indicators of medical history) was 30.2% (95% CI 20.9% to 40.9%). CONCLUSIONS URTIs in children are common, usually self-limiting, conditions that are allocated considerable resources. The results suggest that there may be a need for more thorough holistic assessment of the patient and improved documentation. Since inappropriate prescription of antibiotics for URTIs is still a known problem in Australia, there is a need for consistent, clear communication around antibiotics' lack of impact on symptoms and a high association with undesirable side effects.
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Assessing the quality of health care in the management of bronchiolitis in Australian children: a population-based sample survey. BMJ Qual Saf 2019; 28:817-825. [PMID: 30940731 PMCID: PMC6837255 DOI: 10.1136/bmjqs-2018-009028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 03/12/2019] [Accepted: 03/18/2019] [Indexed: 11/24/2022]
Abstract
Background Bronchiolitis is the most common cause of respiratory hospitalisation in children aged <2 years. Clinical practice guidelines (CPGs) suggest only supportive management of bronchiolitis. However, the availability of CPGs do not guarantee that they are used appropriately and marked variation in the clinical management exists. We conducted an assessment of guideline adherence in the management of bronchiolitis in children at a subnationally representative level including inpatient and ambulatory services in Australia. Methods We searched for national and international CPGs relating to management of bronchiolitis in children and identified 16 recommendations which were formatted into 40 medical record audit indicator questions. A retrospective medical record review assessing compliance with the CPGs was conducted across three types of healthcare setting: hospital inpatient admissions, emergency department (ED) presentations and general practice (GP) consultations in three Australian states for children aged <2 years receiving care in 2012 and 2013. Results Purpose-trained surveyors conducted 13 979 eligible indicator assessments across 796 visits for bronchiolitis at 119 sites. Guideline adherence for management of bronchiolitis was 77.3% (95% CI 72.6 to 81.5) for children attending EDs, 81.6% (95% CI 78.0 to 84.9) for inpatients and 52.3% (95% CI 44.8 to 59.7) for children attending GP consultations. While adherence to some individual indicators was high, overall adherence to documentation of 10 indicators relating to history taking and examination was poorest and estimated at 2.7% (95% CI 1.5 to 4.4). Conclusions The study is the first to assess guideline-adherence in both hospital (ED and inpatient) and GP settings. Our study demonstrated that while the quality of care for bronchiolitis was generally adherent to CPG indicators, specific aspects of management were deficient, especially documentation of history taking.
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Abstract
IMPORTANCE The quality of routine care for children is rarely assessed, and then usually in single settings or for single clinical conditions. OBJECTIVE To estimate the quality of health care for children in Australia in inpatient and ambulatory health care settings. DESIGN, SETTING, AND PARTICIPANTS Multistage stratified sample with medical record review to assess adherence with quality indicators extracted from clinical practice guidelines for 17 common, high-burden clinical conditions (noncommunicable [n = 5], mental health [n = 4], acute infection [n = 7], and injury [n = 1]), such as asthma, attention-deficit/hyperactivity disorder, tonsillitis, and head injury. For these 17 conditions, 479 quality indicators were identified, with the number varying by condition, ranging from 9 for eczema to 54 for head injury. Four hundred medical records were targeted for sampling for each of 15 conditions while 267 records were targeted for anxiety and 133 for depression. Within each selected medical record, all visits for the 17 targeted conditions were identified, and separate quality assessments made for each. Care was evaluated for 6689 children 15 years of age and younger who had 15 240 visits to emergency departments, for inpatient admissions, or to pediatricians and general practitioners in selected urban and rural locations in 3 Australian states. These visits generated 160 202 quality indicator assessments. EXPOSURES Quality indicators were identified through a systematic search of local and international guidelines. Individual indicators were extracted from guidelines and assessed using a 2-stage Delphi process. MAIN OUTCOMES AND MEASURES Quality of care for each clinical condition and overall. RESULTS Of 6689 children with surveyed medical records, 53.6% were aged 0 to 4 years and 55.5% were male. Adherence to quality of care indicators was estimated at 59.8% (95% CI, 57.5%-62.0%; n = 160 202) across the 17 conditions, ranging from a high of 88.8% (95% CI, 83.0%-93.1%; n = 2638) for autism to a low of 43.5% (95% CI, 36.8%-50.4%; n = 2354) for tonsillitis. The mean adherence by condition category was estimated as 60.5% (95% CI, 57.2%-63.8%; n = 41 265) for noncommunicable conditions (range, 52.8%-75.8%); 82.4% (95% CI, 79.0%-85.5%; n = 14 622) for mental health conditions (range, 71.5%-88.8%); 56.3% (95% CI, 53.2%-59.4%; n = 94 037) for acute infections (range, 43.5%-69.8%); and 78.3% (95% CI, 75.1%-81.2%; n = 10 278) for injury. CONCLUSIONS AND RELEVANCE Among a sample of children receiving care in Australia in 2012-2013, the overall prevalence of adherence to quality of care indicators for important conditions was not high. For many of these conditions, the quality of care may be inadequate.
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The application of the Global Trigger Tool: a systematic review. Int J Qual Health Care 2017; 28:640-649. [PMID: 27664822 DOI: 10.1093/intqhc/mzw115] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 08/30/2016] [Indexed: 12/11/2022] Open
Abstract
Purpose This study describes the use of, and modifications and additions made to, the Global Trigger Tool (GTT) since its first release in 2003, and summarizes its findings with respect to counting and characterizing adverse events (AEs). Data sources Peer-reviewed literature up to 31st December 2014. Study selection A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Data extraction Two authors extracted and compiled the demographics, methodologies and results of the selected studies. Results of data synthesis Of the 48 studies meeting the eligibility criteria, 44 collected data from inpatient medical records and four from general practice records. Studies were undertaken in 16 countries. Over half did not follow the standard GTT protocol regarding the number of reviewers used. 'Acts of omission' were included in one quarter of studies. Incident reporting detected between 2% and 8% of AEs that were detected with the GTT. Rates of AEs varied in general inpatient studies between 7% and 40%. Infections, problems with surgical procedures and medication were the most common incident types. Conclusion The GTT is a flexible tool used in a range of settings with varied applications. Substantial differences in AE rates were evident across studies, most likely associated with methodological differences and disparate reviewer interpretations. AE rates should not be compared between institutions or studies. Recommendations include adding 'omission' AEs, using preventability scores for priority setting, and re-framing the GTT's purpose to understand and characterize AEs rather than just counting them.
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Structure-Based design, synthesis and sAR of a novel series of thiopheneamidine urokinase plasminogen activator inhibitors. Bioorg Med Chem Lett 2001; 11:1379-82. [PMID: 11378359 DOI: 10.1016/s0960-894x(01)00247-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The serine protease urokinase plasminogen activator (uPA) is thought to play a central role in tumor metastasis and angiogenesis. Molecular modeling studies suggest that 5-thiomethylthiopheneamidine inhibits uPA by binding at the S1 pocket of the active site. Further structure based elaboration of this residue resulted in a novel class of potent and selective inhibitors of uPA.
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Synthesis of thiophene-2-carboxamidines containing 2-aminothiazoles and their biological evaluation as urokinase inhibitors. Bioorg Med Chem Lett 2001; 11:915-8. [PMID: 11294390 DOI: 10.1016/s0960-894x(01)00102-0] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The serine protease urokinase (uPa) has been implicated in the progression of both breast and prostate cancer. Utilizing structure based design, the synthesis of a series of substituted 4-[2-amino-1,3-thiazolyl]-thiophene-2-carboxamidines is described. Further optimization of this series by substitution of the terminal amine yielded urokinase inhibitors with excellent activities.
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Activin A and TGF-beta stimulate phosphorylation of focal adhesion proteins and cytoskeletal reorganization in rat aortic smooth muscle cells. Exp Cell Res 1999; 251:194-202. [PMID: 10438585 DOI: 10.1006/excr.1999.4573] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Activin A and Transforming Growth Factor-beta (TGF-beta) are members of a common family of cytokines that bind to and stimulate serine/threonine kinase receptors. Activin A and TGF-beta are important during embryonic development exerting both positive and negative effects on cell growth. In the adult organism, they function in processes such as tissue repair, cellular proliferation, and differentiation. Although activin A and TGF-beta often induce opposite functional outcomes in specific cells; proliferation or differentiation, both were found to stimulate the formation of actin stress fibers and focal adhesions in serum-starved rat aortic smooth muscle (RASM) cells. These structural changes were accompanied by phosphorylation of the focal adhesion proteins, paxillin, and p130(cas). Similar cytoskeletal and biochemical changes were observed with the vasoactive agonist angiotensin II. Activation of the ERK/MAP kinase pathway has been implicated in the migration in certain cell types. However, while activin A, TGF-beta, and angiotensin II all stimulated ERK activity in RASM cells, only activin A and angiotensin II stimulated migration. TGF-beta failed to illicit a chemotactic response. Furthermore, pharmacologic inhibition of MEK activity failed to block migration in response to activin A and angiotensin II, indicating RASM migration can occur independent of ERK activity. These results suggest that TGF-beta and activin A share several signaling pathways with angiotensin II leading to cytoskeletal remodeling and ERK activation, but there are distinct differences regarding the effect of these agonists on cellular migration.
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Abstract
Proliferation and directed migration of vascular cells are key components in vascular diseases such as atherosclerosis and restenosis following percutaneous transluminal coronary angioplasty. However, the precise cellular and molecular mechanisms involved in the control of vascular cell proliferation or migration at the tissue level remain largely undefined. Molecules contributing to these processes are elaborated by distinct cell types and act in both autocrine and paracrine modes. They include two broad classes, polypeptide growth factors and vasoactive G-protein-coupled receptor (GPCR) agonists. Examples of the former, such as platelet-derived growth factor, bind to and activate cell surface receptor tyrosine kinases, initiating intracellular biochemical signaling pathways associated with cell proliferation or migration. In contrast, recent evidence suggests that vasoactive GPCR agonists (e.g. angiotensin II, endothelin-1, alpha-thrombin) elicit cell growth indirectly by inducing the production of autocrine or paracrine factors in vascular cells. Recent studies have identified activin A as a novel component of conditioned medium obtained from GPCR agonist-stimulated vascular smooth muscle cells (SMCs). Although activin A alone only weakly stimulated rat aortic SMC DNA synthesis, it demonstrated a potent co-mitogenic effect in combination with either epidermal growth factor (EGF) or heparin binding EGF-like growth factor in these cells, increasing DNA synthesis by up to 5- and 4-fold respectively. Furthermore, in a rat carotid-injury model, activin A mRNA was upregulated within 6 h after injury, followed by increases in immunoreactive protein detected in the expanding neointima 7 to 14 days later. Taken together, these results indicate that activin A is a common vascular SMC-derived growth factor induced by vasoactive agonists that may, either alone or in combination with other factors, contribute to fibroproliferative vascular diseases.
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Epiregulin is a potent vascular smooth muscle cell-derived mitogen induced by angiotensin II, endothelin-1, and thrombin. Proc Natl Acad Sci U S A 1999; 96:1633-8. [PMID: 9990076 PMCID: PMC15542 DOI: 10.1073/pnas.96.4.1633] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Vasoactive GTP-binding protein-coupled receptor agonists such as angiotensin II (AII), endothelin-1 (ET-1), and alpha-thrombin (alpha-Thr) have been reported to indirectly stimulate vascular smooth muscle cell (VSMC) proliferation by regulating the expression of one or more autocrine growth factors. Using ion-exchange, gel-filtration, and reverse-phase chromatographic purification methods, we isolated a major mitogenic protein present in AII-stimulated rat aortic smooth muscle (RASM) cell conditioned medium. Twenty N-terminal amino acids of the purified peptide were identified, and they had 75% amino acid sequence identity with mouse epiregulin, an epidermal growth factor (EGF)-related growth factor. We cloned the cDNA for rat epiregulin to determine its pattern of expression in G-protein-coupled receptor agonist-stimulated cells and confirm its activity as a mitogen. After treatment of RASM cells with AII, ET-1, or alpha-Thr for 1 h, induction of two epiregulin transcripts was observed, including a 4.8-kb transcript and a novel transcript of approximately 1.2 kb. Recombinant rat epiregulin was strongly mitogenic for RASM cells, stimulating DNA synthesis to levels similar to those induced by serum or platelet-derived growth factor and approximately 3-fold above that observed with saturating concentrations of EGF. In addition, epiregulin caused rapid EGF receptor activation in RASM cells. However, relative levels of EGF receptor tyrosine phosphorylation stimulated by epiregulin were less than those induced by EGF or betacellulin. Taken together, these results indicate that epiregulin is a potent VSMC-secreted mitogen, induced in common by AII, ET-1, and alpha-Thr, that may contribute to VSMC proliferation and vascular remodeling stimulated by vasoactive agonists.
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MESH Headings
- 3T3 Cells
- Amino Acid Sequence
- Angiotensin II/pharmacology
- Animals
- Aorta
- Base Sequence
- COS Cells
- Cells, Cultured
- Cloning, Molecular
- Culture Media, Conditioned
- DNA/biosynthesis
- Endothelin-1/pharmacology
- Endothelin-1/physiology
- Epidermal Growth Factor/chemistry
- Epidermal Growth Factor/genetics
- Epidermal Growth Factor/pharmacology
- Epiregulin
- ErbB Receptors/drug effects
- ErbB Receptors/physiology
- Humans
- Mice
- Molecular Sequence Data
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/physiology
- Rats
- Recombinant Proteins/biosynthesis
- Recombinant Proteins/chemistry
- Recombinant Proteins/pharmacology
- Sequence Alignment
- Sequence Homology, Amino Acid
- Thrombin/pharmacology
- Thrombin/physiology
- Transfection
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Stimulation of activin A expression in rat aortic smooth muscle cells by thrombin and angiotensin II correlates with neointimal formation in vivo. J Clin Invest 1997; 100:639-48. [PMID: 9239411 PMCID: PMC508232 DOI: 10.1172/jci119575] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Vasoactive GTP-binding protein-coupled receptor agonists (e.g., angiotensin II [AII] and alpha-thrombin) stimulate the production of mitogenic factors from vascular smooth muscle cells. In experiments to identify mitogens secreted from AII- or alpha-thrombin-stimulated rat aortic smooth muscle (RASM) cells, neutralizing antibodies directed against several growth factors (e.g., PDGF and basic fibroblast growth factor [basic FGF]) failed to inhibit the mitogenic activity of conditioned media samples derived from the cells. In this report, we found that polyclonal neutralizing antibodies directed against purified human placental basic FGF reduced the mitogenic activity of AII-stimulated RASM cell-conditioned media and in immunoblot experiments identified a 26-kD protein (14 kD under reducing conditions) that was distinct from basic FGF. After purification from RASM cell-conditioned medium, amino acid sequence analysis identified the protein as activin A, a member of the TGF-beta superfamily. Increased activin A expression was observed after treatment of the RASM cells with AII, alpha-thrombin, and the protein kinase C agonist PMA. In contrast, PDGF-BB or serum caused only a minor induction of this protein. Although activin A alone only weakly stimulated RASM cell DNA synthesis, it demonstrated a potent comitogenic effect in combination with either EGF or heparin-binding EGF-like growth factor in the RASM cells, increasing DNA synthesis by up to fourfold. Furthermore, in a rat carotid injury model, activin A mRNA was upregulated within 6 h after injury followed by increases in immunoreactive protein detected in the expanding neointima 7 and 14 d later. Taken together, these results indicate that activin A is a vascular smooth muscle cell-derived factor induced by vasoactive agonists that may, either alone or in combination with other vascular derived growth factors, have a role in neointimal formation after arterial injury.
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Thrombin receptor activation elicits rapid protein tyrosine phosphorylation and stimulation of the raf-1/MAP kinase pathway preceding delayed mitogenesis in cultured rat aortic smooth muscle cells: evidence for an obligate autocrine mechanism promoting cell proliferation induced by G-protein-coupled receptor agonist. J Clin Invest 1996; 97:1173-83. [PMID: 8636428 PMCID: PMC507169 DOI: 10.1172/jci118531] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Treatment of quiescent rat aortic smooth muscle cells with either alpha-thrombin or a thrombin receptor-derived agonist peptide (SFLLRNP) resulted in pronounced increases in [3H]thymidine incorporation that were concentration dependent and reached a maximum of approximately 15-fold above serum-starved controls. However, in contrast to FBS, PDGF-BB, or basic fibroblast growth factor (bFGF), that initiated DNA synthesis promptly after 16-19 h, thymidine incorporation in response to thrombin was delayed by an additional 3-6 h. Delayed mitogenesis correlated with the appearance of a potent mitogenic activity in conditioned media samples obtained from thrombin-stimulated rat aortic smooth muscle cells, as assayed using Swiss 3T3 fibroblasts. This activity was not inhibited by neutralizing antibodies directed against PDGF or bFGF. Furthermore, in the Swiss 3T3 cells, simple addition of either alpha-thrombin or SFLLRNP failed to elicit a significant mitogenic response. In signal transduction studies, both thrombin and SFLLRNP treatment led to rapid tyrosine phosphorylation of proteins with apparent molecular masses of 42, 44, 75, 120, and 190 kD, respectively, as assessed by antiphosphotyrosine immunoblotting. The overall pattern of protein tyrosine phosphorylation was distinct from that observed after PDGF-BB addition. Activation of Raf-1 and the mitogen-activated protein (MAP) kinases p44mapk and p42mapk was also observed. However, the time course and duration of Raf-1/MAP kinase activation after thrombin stimulation were similar to those elicited by PDGF-BB. Taken together, our results indicate that thrombin-stimulated vascular smooth muscle proliferation is delayed and requires the de novo expression of one or more autocrine mitogens. In addition, the rapid induction of discrete intracellular signaling mechanisms by thrombin, including the Raf-1/MAP kinase pathway, appears to be insufficient alone to promote vascular smooth muscle cell mitogenesis.
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Orally active endothelin receptor antagonist BMS-182874 suppresses neointimal development in balloon-injured rat carotid arteries. J Cardiovasc Pharmacol 1995; 26:908-15. [PMID: 8606527 DOI: 10.1097/00005344-199512000-00009] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Vascular smooth muscle cell (SMC) proliferation is an important component in the development of restenosis. Because endothelin (ET) has been reported to act as an SMC mitogen, we postulated that the orally active ETA receptor antagonist BMS-182874 would suppress the development of the intimal lesion that develops in rat carotid arteries after balloon injury. Using cultured rat aortic SMC, we noted that ET-1-stimulated increases in [3H]thymidine incorporation were blocked by BMS-182874. To determine the effect of the drug on intimal lesion formation, we treated rats with BMS-182874 (100 mg/kg orally, p.o.) or vehicle once daily for 3 weeks, beginning 1 week before balloon injury. Two weeks after injury, drug-treated rats had a 35% decrease in lesion area and a 34% decrease in the lesion/media ratio as compared with the vehicle-treated rats. In situ hybridization (ISH) analysis of balloon-injured rat carotid arteries showed an increase in ETA receptor mRNA. These data support the concept that ETA receptor activation contributes to intimal lesion formation by promotion of SMC proliferation and suggest a potential use for ETA receptor antagonists in the amelioration of hyperproliferative vascular diseases, including restenosis.
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MESH Headings
- Administration, Oral
- Animals
- Carotid Arteries/drug effects
- Carotid Arteries/pathology
- Catheterization
- Cell Division/drug effects
- DNA/biosynthesis
- Dansyl Compounds/pharmacology
- Endothelin Receptor Antagonists
- Male
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/pathology
- Rats
- Rats, Sprague-Dawley
- Receptor, Endothelin A
- Receptor, Endothelin B
- Receptors, Endothelin/analysis
- Receptors, Endothelin/genetics
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Angiotensin II stimulation of rapid paxillin tyrosine phosphorylation correlates with the formation of focal adhesions in rat aortic smooth muscle cells. J Cell Sci 1995; 108 ( Pt 1):333-42. [PMID: 7537746 DOI: 10.1242/jcs.108.1.333] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Angiotensin II is a potent vasoconstrictor that has been also implicated in vascular hyperproliferative diseases, including atherosclerosis and restenosis following angioplasty. Treatment of cultured, serum-starved rat aortic smooth muscle cells with angiotensin II causes rapid protein tyrosine phosphorylation that precedes cell mitogenesis. We have identified two of the phosphoproteins as paxillin (75 kilodaltons) and the tyrosine kinase pp125Fak, both components of actin-associated focal adhesion sites. Angiotensin II stimulated a 5-fold increase in the tyrosine phosphorylation of paxillin and a smaller (1.5-fold) increase in pp125Fak tyrosine phosphorylation. Paxillin tyrosine phosphorylation was evident within 1 minute, and was maximal after 10 minutes. Similar elevated protein tyrosine phosphorylation levels of paxillin were obtained with exposure of the rat aortic smooth muscle cells to peptides endothelin-1 and alpha-thrombin that function, as angiotensin II, through binding to members of the seven transmembrane domain G protein coupled receptors. Angiotensin II treatment also stimulated the production of a well-ordered actin-containing stress fiber network and prominent paxillin-containing focal adhesions. The focal adhesions stained intensely with anti-phosphotyrosine antibody suggesting the tyrosine phosphorylation of paxillin and cytoskeletal reorganization were tightly coupled. Angiotensin II receptor occupancy has been shown previously to lead to protein kinase C activation. However, compared to angiotensin II stimulation, a smaller, delayed increase in paxillin tyrosine phosphorylation was observed following direct protein kinase C activation by the phorbol ester phorbol 12-myristate-13-acetate. Paxillin tyrosine phosphorylation was selective for certain agonists since no increase in tyrosine phosphorylation of this protein was observed following exposure to the potent mitogen PDGF. Thus, actin-based cytoskeletal changes involving sites of cell adhesion to the extracellular matrix may play an important role in normal and pathophysiologic smooth muscle cell growth regulation in response to certain angiotensin II-type vasoactive agonists.
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Abstract
Repetitive physical tasks, particularly executed with force or using vibrating hand tools, carry the chief risk of carpal tunnel syndrome for workers. Treatment may require removing the worker from the task or redesigning the task for the worker, while proper attention to ergonomics can prevent carpal tunnel injuries in the first place.
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Alterations in expression of p56lck during myeloid differentiation of LSTRA cells. CELL GROWTH & DIFFERENTIATION : THE MOLECULAR BIOLOGY JOURNAL OF THE AMERICAN ASSOCIATION FOR CANCER RESEARCH 1994; 5:1215-23. [PMID: 7531490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The src-related tyrosine kinase p56lck is overexpressed in the mouse leukemia cell line LSTRA. Although p56lck is thought to be a specific T-cell marker, we found that LSTRA cells can be induced to differentiate towards macrophages or granulocytes by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate or the cyclic nucleotide analogue, dibutyryl cAMP, respectively. Treatment of LSTRA cells with 12-O-tetradecanoylphorbol-13-acetate resulted in marked alterations in morphology including increased size, adherence, and spreading on culture dishes. These cells also ceased proliferating, accumulated in G0-G1 and expressed nonspecific esterase activity. In contrast, although LSTRA cells treated with dibutyryl cAMP stopped growing and accumulated in G0-G1, these cells expressed functionally active chemotactic peptide receptors and became irregular and granular in appearance. Differentiation of LSTRA cells was also found to be associated with altered expression of p56lck. Thus, while 12-O-tetradecanoylphorbol-13-acetate treatment caused the cells to produce higher molecular weight forms of p56lck, dibutyryl cAMP treatment resulted in increased expression of total p56lck mRNA as well as the more mature type II p56lck mRNA transcript. There were no major alterations in p56lck kinase activity in vitro following differentiation. Phospholipase C gamma and p21rasGAP, two putative substrates for the tyrosine kinase activity of p56lck, were found to be constitutively phosphorylated on tyrosine in LSTRA cells. Tyrosine phosphorylation of these substrates was not altered following differentiation. These results indicate that LSTRA cells are relatively early precursors that have the capacity to develop along the myeloid differentiation pathway.(ABSTRACT TRUNCATED AT 250 WORDS)
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Uneven distribution of protein kinase C-alpha and -beta isozymes in human sarcomas and carcinomas. J Cell Physiol 1994; 159:434-40. [PMID: 8188761 DOI: 10.1002/jcp.1041590307] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Protein kinase C (PKC) represents a family of structurally related Ser/Tre kinases which are involved in mitogenic signalling and may contribute to human neoplasia. To address this issue, the messenger RNA and protein levels of PKC isoenzymes alpha and beta were analyzed in several human sarcoma- and carcinoma-derived cell lines. Carcinomas contained low or undetectable levels of either PKC-alpha or PKC-beta. Sarcomas exhibited similar or increased PKC expression compared to human diploid fibroblasts. Moreover, sarcoma cell lines expressing one PKC isoform did not contain detectable levels of the other. When PKC was depleted from the tumor cells, we observed that the PKC overexpressing sarcomas had reduced their malignant properties as determined by their ability to grow in semisolid medium. In addition, epidermal growth factor-stimulated and erbB2-transformed fibroblasts exhibited enhanced cell growth in the absence of PKC. We propose a model for the effect of PKC as a negative regulator of proliferation in epithelial cells and a growth promoter in fibroblasts.
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Endothelin-1 and angiotensin-II stimulate delayed mitogenesis in cultured rat aortic smooth muscle cells: evidence for common signaling mechanisms. Mol Endocrinol 1994; 8:148-58. [PMID: 8170471 DOI: 10.1210/mend.8.2.8170471] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The vasoactive peptides endothelin-1 (ET-1) and angiotensin-II (AII) have been implicated in chronic hypertension and may play important roles in related vascular diseases such as restenosis and atherosclerosis. Using a rat aortic smooth muscle (RASM) cell model, both ET-1 and AII induced concentration-dependent delayed increases in DNA synthesis relative to that in the serum-deprived controls. Stimulation of DNA synthesis was maximal at 100 nM for each peptide. All treatment of RASM cells resulted in a greater mitogenic effect (4- to 7-fold) than that observed for ET-1 (3-fold). When added in the presence of AII, ET-1 had a supplemental effect on DNA synthesis (5- to 10-fold above control). Although RASM cells expressed both ETA and AT1 receptors, radioligand binding experiments indicated that approximately 10-fold as many AT1 receptors as ETA receptors were present. In signal transduction studies, ET-1 and AII each elicited concentration-dependent increases in the intracellular Ca2+ concentration. ET-1 and AII also stimulated phosphoinositide metabolism and phosphorylation of a specific substrate for protein kinase-C. The release of total inositol phosphates in response to ET-1 and AII was concentration dependent and inhibited by the ETA receptor-selective antagonist BQ-123 and the AT1 receptor-selective antagonist losartan, respectively. In addition, tyrosine phosphorylation of 120- and 75-kilodalton proteins as well as the mitogen-activated protein kinases p44mapk and p42mapk was observed within 5 min of the addition of either ET-1 or AII. Taken together, these data indicate that ET-1 and AII may promote smooth muscle cell growth through common intracellular signaling mechanisms.
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Angiotensin II induces delayed mitogenesis and cellular proliferation in rat aortic smooth muscle cells. Correlation with the expression of specific endogenous growth factors and reversal by suramin. J Clin Invest 1994; 93:788-98. [PMID: 7509348 PMCID: PMC293930 DOI: 10.1172/jci117033] [Citation(s) in RCA: 121] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
By means of a rat aortic smooth muscle (RASM) cell culture model, the effects of angiotensin II (AII) on early proto-oncogene gene expression, DNA synthesis, and cell proliferation were measured and compared to known mitogens. In 24-h [3H]-thymidine incorporation assays, AII was found to be a weak mitogen when compared to potent mitogens such as fetal bovine serum and platelet-derived growth factor (PDGF). In contrast, when assays were carried out for 48 h, AII induced a significant dose-dependent stimulation of DNA synthesis, which more than doubled at 3 nM AII, and was maximal (five- to eightfold above control) at 100 nM AII. Treatment of cells with the AII type 1 receptor antagonist losartan inhibited the mitogenic effects of AII. AII also stimulated smooth muscle cell proliferation, as indicated by an absolute increase in cell number after AII stimulation of RASM cells for 5 d. AII stimulation of RASM cell growth correlated with the increased expression of specific endogenous growth factors, including transforming growth factor beta 1 (TGF-beta 1) and PDGF A-chain. However, addition of either PDGF- or TGF-beta 1-neutralizing antibodies failed to significantly reduce the delayed mitogenic effects induced by AII. In contrast, we found that AII-stimulated mitogenesis could be inhibited in a dose-dependent manner by the growth factor inhibitor drug suramin. Taken together, our results indicate that enhanced endogenous growth factor expression may represent the direct mechanism by which AII promotes smooth muscle cell growth in some vascular hyperproliferative diseases.
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MESH Headings
- 3T3 Cells
- Angiotensin II/antagonists & inhibitors
- Angiotensin II/pharmacology
- Animals
- Antibodies/pharmacology
- Aorta/cytology
- Aorta/drug effects
- Aorta/metabolism
- Becaplermin
- Cell Division/drug effects
- Culture Media, Conditioned
- DNA/biosynthesis
- Dose-Response Relationship, Drug
- Genes, fos/drug effects
- Growth Substances/biosynthesis
- Growth Substances/immunology
- Kinetics
- Mice
- Mitogens/antagonists & inhibitors
- Mitogens/pharmacology
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Phosphoproteins/metabolism
- Phosphotyrosine
- Platelet-Derived Growth Factor/immunology
- Platelet-Derived Growth Factor/pharmacology
- Platelet-Derived Growth Factor/physiology
- Proto-Oncogene Proteins c-sis
- Rats
- Rats, Sprague-Dawley
- Recombinant Proteins/pharmacology
- Suramin/pharmacology
- Thymidine/metabolism
- Tyrosine/analogs & derivatives
- Tyrosine/metabolism
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Effects of thrombin receptor activating peptide on phosphoinositide hydrolysis and protein kinase C activation in cultured rat aortic smooth muscle cells: evidence for "tethered-ligand" activation of smooth muscle cell thrombin receptors. Biochem Pharmacol 1993; 45:1577-82. [PMID: 8387299 DOI: 10.1016/0006-2952(93)90297-a] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Phosphoinositide hydrolysis and protein kinase C (PKC) activation were examined in response to treatment of rat aortic smooth muscle cells with alpha-thrombin and a seven amino acid thrombin receptor activating peptide (TRAP-7; SFLLRNP). alpha-Thrombin and TRAP-7 stimulated total inositol phosphate (IP) accumulation and phosphorylation of a specific endogenous substrate for activated PKC. Acetylated TRAP-7 and "reverse" TRAP (FSLLRNPNDKYEPF) were ineffective in stimulating signal transduction. The active site inhibitor, MD805 (argatroban), and the anion-binding exosite inhibitor, BMS 180,742, reduced the IP response to alpha-thrombin in a concentration-dependent manner. In contrast, the TRAP-7-induced IP response was not affected by either inhibitor. These data are consistent with the tethered-ligand hypothesis for thrombin receptor activation in rat aortic smooth muscle cells.
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Angiotensin II stimulation of rapid protein tyrosine phosphorylation and protein kinase activation in rat aortic smooth muscle cells. J Biol Chem 1993; 268:7338-45. [PMID: 8385103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
In cultured rat aortic smooth muscle cells, angiotensin II (AII) treatment led to increased tyrosine phosphorylation of cellular proteins with apparent molecular masses of 42, 44, 75, and 120 kDa, respectively, as assessed by antiphosphotyrosine immunoblotting. Increased protein tyrosine phosphorylation was observed within 1 min of AII addition and was maximal by 30 min. The overall pattern of AII-stimulated protein tyrosine phosphorylation was distinct from that observed following treatment of rat aortic smooth muscle cells with platelet-derived growth factor-BB. Specific antibodies were used to identify the AII-stimulated 42- and 44-kDa tyrosine-phosphorylated proteins as the "mitogen-activated protein kinases," p42mapk and p44mapk, respectively. Raf-1, a 70-74-kDa serine/threonine protein kinase, was not tyrosine-phosphorylated in response to AII but was found to be hyperphosphorylated as evidenced by retarded protein mobility in SDS gel analysis. Taken together, these data indicate that AII binding to vascular smooth muscle cells leads to rapid activation of a complex cascade of protein kinases, including protein kinase C, Raf-1, MAP kinases, and an undefined intracellular protein tyrosine kinase(s) that may be coordinately involved in signal transduction leading to cell proliferation.
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Abstract
We have reviewed 35 years experience of extradural haemorrhage (EDH) in a large neurosurgical unit, based in two university hospitals, one dealing exclusively with children and the other a general hospital. A steady reduction in the mortality rate from 29 to 8.5% occurred during that period. A trend towards earlier diagnosis is noted and an increasing proportion of rural patients has been evident throughout the study period. During the time-period studied there were many significant developments: the establishment of a modern neurosurgical unit, the evolution of an intensive care unit, the availability of CT head scanning and the formal organization of rapid retrieval to service country areas. However, no single feature could be identified as the major contributor to falling mortality results. Clinical awareness and early diagnosis are the keys to successful management of EDH.
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Platelet-derived growth factor stimulation of GTPase-activating protein tyrosine phosphorylation in control and c-H-ras-expressing NIH 3T3 cells correlates with p21ras activation. Mol Cell Biol 1992; 12:3903-9. [PMID: 1508192 PMCID: PMC360268 DOI: 10.1128/mcb.12.9.3903-3909.1992] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Platelet-derived growth factor (PDGF) stimulation of NIH 3T3 cells leads to the rapid tyrosine phosphorylation of the GTPase-activating protein (GAP) and an associated 64- to 62-kDa tyrosine-phosphorylated protein (p64/62). To assess the functions of these proteins, we evaluated their phosphorylation state in normal NIH 3T3 cells as well as in cells transformed by oncogenically activated v-H-ras or overexpression of c-H-ras genes. No significant GAP tyrosine phosphorylation was observed in unstimulated cultures, while PDGF-BB induced rapid tyrosine phosphorylation of GAP in all cell lines analyzed. In NIH 3T3 cells, we found that PDGF stimulation led to the recovery of between 37 and 52% of GAP molecules by immunoprecipitation with monoclonal antiphosphotyrosine antibodies. Furthermore, PDGF exposure led to a rapid and sustained increase in the levels of p21ras bound to GTP, with kinetics similar to those observed for GAP tyrosine phosphorylation. The PDGF-induced increases in GTP-bound p21ras in NIH 3T3 cells were comparable to the steady-state level observed in serum-starved c-H-ras-overexpressing transformants, conditions in which these cells maintained high rates of DNA synthesis. These results imply that the level of p21ras activation following PDGF stimulation of NIH 3T3 cells is sufficient to support mitogenic stimulation. Addition of PDGF to c-H-ras-overexpressing cells also resulted in a rapid and sustained increase in GTP-bound p21ras. In these cells GAP, but not p64/62, showed increased tyrosine phosphorylation, with kinetics similar to those observed for increased GTP-bound p21ras. All of these findings support a role for GAP tyrosine phosphorylation in p21ras activation and mitogenic signaling.
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Demonstration of an activated platelet-derived growth factor autocrine pathway and its role in human tumor cell proliferation in vitro. Oncogene 1992; 7:1355-9. [PMID: 1320245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In tumor cells expressing platelet-derived growth factor (PDGF) ligand(s) and receptor(s), immunoblot analysis established tyrosine phosphorylation of PDGF receptors (PDGFRs) in the absence of any exogenous ligand, implying chronic receptor activation. Exposure to suramin resulted in diminished receptor autophosphorylation and/or up-regulation of receptor protein. In a subset of such tumor lines, there was a marked reduction in DNA synthesis in response to suramin or PDGF-neutralizing antiserum. These findings demonstrate that autocrine PDGF stimulation contributes to proliferation of some human tumors and that agents which interfere with ligand-receptor interactions at the cell surface can significantly interfere in this process.
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Altered expression of a mouse epidermal cytoskeletal protein is a sensitive marker for proliferation induced by tumor promoters. Carcinogenesis 1992; 13:963-8. [PMID: 1600617 DOI: 10.1093/carcin/13.6.963] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Treatment of mouse skin with tumor promoters such as 12-O-tetradecanoylphorbol-13-acetate (TPA), 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD) or 8-methoxypsoralen and ultraviolet light (PUVA) caused a marked decrease in the expression of p48, an acidic epidermal protein. This protein was specifically identified in mouse epidermis and confluent PAM 212 mouse keratinocytes in culture. Extraction of p48 required strong denaturing conditions (greater than 8 M urea) as well as a reducing agent, indicating that this protein was associated with the cytoskeleton. Positive immunoblot staining of p48 with antikeratin monoclonal antibodies following two-dimensional polyacrylamide gel electrophoresis suggested that this protein may be related to the acidic keratins. The sensitivity of this protein to topically applied mitogens and tumor promoters implies that p48 expression is important in normal epidermal cell growth and differentiation.
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Characterization of platelet-derived growth factor and platelet-derived growth factor receptor expression in asbestos-induced rat mesothelioma. Cancer Res 1992; 52:301-6. [PMID: 1309438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Although altered expression of platelet-derived growth factor (PDGF) is a hallmark of human mesothelioma, expression of PDGF receptors has not been characterized in this cell type. In addition, the expression of this growth factor and its cognate receptor in rodent mesothelioma has not been investigated. In this study, examination of transformed mesothelial cells derived from asbestos-induced rat mesotheliomas revealed that these cells expressed high affinity PDGF receptors (Kd = 0.5 nM) and receptor number was 1.6 x 10(5)/cell. Western analysis using antibodies specific for either the alpha-type or beta-type PDGF receptor and Northern analysis using probes specific for alpha- and beta-type receptor RNA transcripts indicated that these cells expressed beta-type PDGF receptors but that alpha-type receptors could not be detected. However, when the mesothelioma-derived cells were examined for the expression of PDGF, no expression of this growth factor could be detected. The transformed cells expressed no detectable A- or B-chain PDGF RNA transcripts; and using a competitive enzyme immunoassay specific for isoforms containing the B chain of PDGF and a sandwich enzyme-linked immunosorbent assay specific for A-chain-containing isoforms, neither AA, nor AB, nor BB isoforms of this growth factor could be detected in medium conditioned by these cells. The absence of alterations in PDGF expression in rat mesothelioma, in contrast to the data for the human disease, suggests that the production of this growth factor by transformed mesothelial cells may be species specific.
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Activation of the colony-stimulating factor 1 receptor leads to the rapid tyrosine phosphorylation of GTPase-activating protein and activation of cellular p21ras. Oncogene 1992; 7:147-52. [PMID: 1311060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We have previously reported that platelet-derived growth factor (PDGF) induced tyrosine phosphorylation of GTPase-activating protein (GAP) in intact quiescent fibroblasts under conditions in which insulin and basic fibroblast growth factor (bFGF) were ineffective (Molloy et al., 1988). In the present study, we have provided evidence that colony-stimulating factor 1 (CSF-1) is capable of inducing tyrosine phosphorylation of GAP and its associated cellular proteins, p62 and p190, in NIH3T3 cells overexpressing the human CSF-1 receptor (CSF-1R). However, the extent of GAP tyrosine phosphorylation induced by CSF-1 was approximately 10% of that induced by PDGF-BB in the NIH3T3 fibroblasts. Despite this significant difference, both PDGF-BB and CSF-1 increased the activation of p21ras, the extent of which correlated well with the mitogenic response induced by each growth factor in these cells. Taken together, our findings provide evidence for a possible role of tyrosine phosphorylation of GAP and GAP-associated phosphoproteins in regulating transduction of CSF-1-induced mitogenic signals through p21ras activation.
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Development of a highly efficient expression cDNA cloning system: application to oncogene isolation. Proc Natl Acad Sci U S A 1991; 88:5167-71. [PMID: 2052597 PMCID: PMC51833 DOI: 10.1073/pnas.88.12.5167] [Citation(s) in RCA: 120] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
We developed an expression cDNA cloning system capable of generating high-complexity libraries with unidirectionally inserted cDNA fragments and allowing efficient plasmid rescue. As an application of this system, a cDNA library was constructed from an NIH 3T3 transformant induced by mouse hepatocellular carcinoma DNA. Transfection of NIH 3T3 cells by the library DNA led to the detection of several transformed foci from which identical plasmids with transforming ability could be rescued. Structure and sequence analysis of the cDNA clones revealed that the oncogene was created by recombinational events involving an unknown gene and the mouse homologue of the B-raf protooncogene. Detection of the same genetic rearrangement in independent primary transformants implied that generation of the oncogene occurred within the tumor rather than during DNA transfection or cDNA library construction. The high frequency at which clones were identified and the large sizes of some of the transforming cDNA inserts isolated suggest wide applicability of this mammalian expression cloning system for isolating cDNAs of biologic interest.
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The erbB-2 mitogenic signaling pathway: tyrosine phosphorylation of phospholipase C-gamma and GTPase-activating protein does not correlate with erbB-2 mitogenic potency. Mol Cell Biol 1991; 11:2040-8. [PMID: 1672440 PMCID: PMC359891 DOI: 10.1128/mcb.11.4.2040-2048.1991] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The erbB-2 gene product, gp185erbB-2, unlike the structurally related epidermal growth factor (EGF) receptor (EGFR), exhibits constitutive kinase and transforming activity. We used a chimeric EGFR/erbB-2 expression vector to compare the mitogenic signaling pathway of the erbB-2 kinase with that of the EGFR, at similar levels of expression, in response to EGF stimulation. The EGFR/erbB-2 chimera was significantly more active in inducing DNA synthesis than the EGFR when either was expressed in NIH 3T3 cells. Analysis of biochemical pathways implicated in signal transduction by growth factor receptors indicated that both phospholipase C type gamma (PLC-gamma) and the p21ras GTPase-activating protein (GAP) are substrates for the erbB-2 kinase in NIH 3T3 fibroblasts. However, under conditions in which activation of the erbB-2 kinase induced DNA synthesis at least fivefold more efficiently than the EGFR, the levels of erbB-2- or EGFR-induced tyrosine phosphorylation of PLC-gamma and GAP were comparable. In addition, the stoichiometry of tyrosine phosphorylation of these putative substrates by erbB-2 appeared to be at least an order of magnitude lower than that induced by platelet-derived growth factor receptors at comparable levels of mitogenic potency. Thus, our results indicate that differences in tyrosine phosphorylation of PLC-gamma and GAP do not account for the differences in mitogenic activity of the erbB-2 kinase compared with either the EGFR or platelet-derived growth factor receptor in NIH 3T3 fibroblasts.
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Abstract
A case of extradural haematoma as the presenting feature of an arachnoid cyst is described. Haemorrhagic complications of arachnoid cysts are well known, but extradural haematoma is rare. A possible pathogenetic mechanism is proposed and the treatment of asymptomatic arachnoid cysts is discussed.
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45
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Abstract
One hundred and two paediatric cases of extradural haemorrhage (EDH) were treated in Adelaide, South Australia, during the period 1954-1988; 10 were infants (0-2 years) and 92 were children (2-14 years). There were 9 deaths (mortality 8.8%). Long-term disabilities severe enough to interfere with school and/or employment were seen in 8 (7.8%) survivors. This relatively low number of adverse outcomes is partly an expression of a low incidence (5.9%) of associated intradural haematomas and few high-velocity impacts due to vehicular accidents. There is reason to believe that the results of treatment have improved in the decade 1977-1988. We attribute this in part to early diagnosis by computed tomography (CT), but a contributory factor may be earlier referrals from country centres to a paediatric trauma centre and rapid transfer, by air or road, by medical retrieval teams.
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Overexpression of phospholipase C-gamma in NIH 3T3 fibroblasts results in increased phosphatidylinositol hydrolysis in response to platelet-derived growth factor and basic fibroblast growth factor. Mol Cell Biol 1990; 10:6069-72. [PMID: 2172791 PMCID: PMC361408 DOI: 10.1128/mcb.10.11.6069-6072.1990] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Overexpression of phospholipase C-gamma in fibroblasts led to increased tyrosine phosphorylation of this enzyme in response to platelet-derived growth factor and basic fibroblast growth factor. This correlated with increased phosphoinositide release but not with enhanced mitogenicity. Thus, phospholipase C-gamma-mediated phosphoinositide metabolism may not be limiting in the signaling pathways initiated by these growth factors.
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Abstract
In order to investigate the effects of protein kinase C (PKC) expression on cellular growth and morphology, we established mouse fibroblast cell populations which expressed the rat pkc-gamma gene under the control of a retroviral promoter. NIH 3T3 stable transfectants displayed a three-fold increase in total PKC levels. These cells appeared morphologically unaltered but exhibited a stronger mitogenic response to 12-O-tetradecanoylphorbol-13-acetate (TPA) and cardiolipin (CL) as well as enhanced growth in semisolid medium in the presence of TPA. Thus, at these enzyme levels, PKC conferred growth advantages to NIH 3T3 cells only in response to specific activators.
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48
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Abstract
The cascade of biochemical events triggered by growth factors and their receptors is central to understanding normal cell-growth regulation and its subversion in cancer. Ras proteins (p21ras) have been implicated in signal transduction pathways used by several growth factors, including platelet-derived growth factor (PDGF). These guanine nucleotide-binding Ras proteins specifically interact with a cellular GTPase-activating protein (GAP). Here we report that in intact quiescent fibroblasts, both AA and BB homodimers of PDGF rapidly induce tyrosine phosphorylation of GAP under conditions in which insulin and basic fibroblast growth factor (bFGF) are ineffective. Although GAP is located predominantly in the cytosol, most tyrosine-phosphorylated GAP is associated with the cell membrane, the site of p21ras biological activity. These results provide a direct biochemical link between activated PDGF-receptor tyrosine kinases and the p21ras-GAP mitogenic signalling system.
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Autocrine mechanism for v-sis transformation requires cell surface localization of internally activated growth factor receptors. Proc Natl Acad Sci U S A 1989; 86:8063-7. [PMID: 2813378 PMCID: PMC298215 DOI: 10.1073/pnas.86.20.8063] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
v-sis represents a prototype for the class of oncogenes that encode growth factors. Whether its platelet-derived growth factor (PDGF)-like product functionally activates its receptors within the cell or at the cell surface has potential implications in efforts to intervene with the v-sis-transformed phenotype. We demonstrate that intracellular as well as cell surface forms of two PDGF receptor gene products are tyrosine phosphorylated in v-sis transformants. In a chemically defined medium in which cell growth was dependent on v-sis expression, proliferation was partially inhibited by PDGF neutralizing antibody but completely blocked by suramin. Suramin treatment resulted in a marked reduction in tyrosine phosphorylated cell surface PDGF receptors but had no effect on the level of tyrosine phosphorylation of intracellular receptor species. All of these findings demonstrate that the v-sis-encoded mitogen can bind and activate its receptors internally but that activated receptors must achieve a cell surface location in order to functionally couple with intracellular mitogenic signaling pathways.
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The calcium signal for Balb/MK keratinocyte terminal differentiation induces sustained alterations in phosphoinositide metabolism without detectable protein kinase C activation. J Biol Chem 1989; 264:11228-35. [PMID: 2472392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Balb/MK keratinocytes require epidermal growth factor for proliferation and terminally differentiate in response to elevated extracellular Ca2+ concentrations. The molecular pathways controlling cell differentiation in this system have yet to be established. We show that a dramatic and sustained activation of phosphoinositide metabolism is produced upon addition of Ca2+ to Balb/MK cultures. The pattern of inositol trisphosphate isomers released in response to Ca2+ challenge appeared to be atypical. Inositol 1,3,4-trisphosphate release was observed by 30s and was produced earlier than any alteration in inositol 1,4,5-trisphosphate levels. Concomitant with the liberation of inositol phosphates, an increased production of diacylglycerol was observed. Despite a 3-fold increase in diacylglycerol levels detected even at 12 h after Ca2+ addition, no evidence of functional activation or down-regulation of protein kinase C was found. This was established by measuring p80 phosphorylation, epidermal growth factor binding, and protein kinase C levels by immunoblotting. Analysis of the diacylglycerol generated following Ca2+ addition to Balb/MK cells revealed that a significant proportion of that lipid was an alkyl ether glyceride molecular species. Therefore, it is possible that this diacylglycerol molecular species may play a role in the Ca2+-induced differentiation program of Balb/MK cells through mechanisms other than stimulation of classical protein kinase C.
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