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1.
Turk J Pediatr ; 64(6): 1021-1030, 2022.
Article in English | MEDLINE | ID: mdl-36583884

ABSTRACT

BACKGROUND: The present study assesses the immune response in children with viral-induced wheezing by examining the two factors-interferon-gamma (IFN-γ) and periostin in serum and nasopharyngeal aspirate (NPA). The aim was to find a pattern with the severity and frequency of wheezing episodes. METHODS: Sixty-nine infants (40 boys and 29 girls), with a mean age of 11.4±6 (2 - 23) months, hospitalized with a first or recurrent episode of bronchial obstruction were enrolled in this study. The serum and NPA concentrations of IFN-γ and periostin were assessed by ELISA methodology. Fifty of the children (72%) were followed for 2 years. RESULTS: We detected lower NPA IFN-γ production in boys, infants with atopic status, family history of asthma, and respiratory syncytial virus infection. Recurrent wheezing in children was associated with a twice lower concentration of IFN-γ in NPA compared to those with the first episode (7.1 vs. 14.8 pg/ml, p=0.05). Higher serum periostin level was established in children over 12 mo in the group of recurrent wheezers with persistent manifestations compared to those without symptoms during the follow-up (410.5 vs. 269.7 ng/ml, p = 0.03). Multivariate logistical regression model assessed high level of serum periostin, male gender, atopy, family history of asthma, and severity of the attack as significant risk factors for persistent compared to intermittent wheezing (r < sup > 2 < /sup > = 0.87, p = 0.04). CONCLUSIONS: Our results demonstrated that recurrent viral-induced wheezing is associated with decreased IFN-γ production and increased periostin response and their correlation with severity and persistence of symptoms were the main outcome measures.


Subject(s)
Asthma , Respiratory Syncytial Virus Infections , Child , Female , Infant , Humans , Male , Child, Preschool , Adolescent , Interferon-gamma , Respiratory Sounds/etiology , Follow-Up Studies , Respiratory Syncytial Virus Infections/complications , Asthma/complications
2.
Intervirology ; 64(4): 194-202, 2021.
Article in English | MEDLINE | ID: mdl-34304230

ABSTRACT

INTRODUCTION: We investigated the prevalence of human metapneumovirus (hMPV) among patients with acute respiratory infections in Bulgaria, and performed genetic characterization of the F gene of these strains. METHODS: Nasopharyngeal swabs collected from patients of a range of ages were tested by using real-time PCR for 12 respiratory viruses. The F gene was sequenced, and phylogenetic and amino acid analyses of the F gene/protein were performed. RESULTS: A total of 1,842 patients were examined during a 3-year period; 1,229 patients (66.7%) were positive for at least one respiratory virus. hMPV was identified in 83 (4.5%) patient samples. Eleven (13%) of hMPV-positive patients were coinfected with another respiratory virus. The hMPV incidence rate in the 2016/2017, 2017/2018, and 2018/2019 winter seasons was 5.4, 5.4, and 3.1%, respectively. hMPV was mainly detected in specimens collected between January and May (89.2% of cases). The incidence of hMPV infection was highest (5.1%) among the youngest age-group (0-4 years), where hMPV was a causative agent in 8.1 and 4.8% of bronchiolitis and pneumonia cases, respectively. Among the patients aged ≥5 years, hMPV was detected in 2.2 and 3.2% of cases of pneumonia and central nervous system infections, respectively. Phylogenetic analysis of the F gene showed that the sequenced hMPV strains belonged to the A2b, B1, and B2 genotypes. Numerous amino acid substitutions were identified compared with the NL00/1 prototype strain. CONCLUSION: This study revealed the significant role of hMPV as a causative agent of serious respiratory illnesses in early childhood, and also demonstrated year-to-year changes in hMPV prevalence and genetic diversity in circulating strains.


Subject(s)
Metapneumovirus , Paramyxoviridae Infections , Respiratory Tract Infections , Bulgaria/epidemiology , Child, Preschool , Genotype , Humans , Infant , Infant, Newborn , Metapneumovirus/genetics , Paramyxoviridae Infections/epidemiology , Phylogeny , Prevalence , Respiratory Tract Infections/epidemiology
3.
Aust Health Rev ; 45(4): 521-522, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33583489

ABSTRACT

Despite Western Australia having low COVID-19 case numbers and limited community transmission, cancer service delivery changes were introduced early in the pandemic, including adoption of telehealth. Patients attending telehealth appointments during COVID-19 between 11 May 2020 and 7 August 2020 reported that telehealth lessened their concerns and met their needs to varying degrees. Despite this, 56% of patients still preferred in-person appointments.


Subject(s)
COVID-19 , Neoplasms , Telemedicine , Humans , Neoplasms/therapy , SARS-CoV-2 , Trust , Western Australia
4.
Aust Health Rev ; 45(2): 148-156, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33587885

ABSTRACT

Objective To determine the extent of medical and non-medical out-of-pocket expenses (OOPE) among regional/rural and outer metropolitan Western Australian patients diagnosed with cancer, and the factors associated with higher costs. Methods Cross-sectional data were collected from adult patients living in four regional/rural areas and two outer metropolitan regions in Western Australia who had been diagnosed with breast, prostate, colorectal or lung cancer. Consenting participants were mailed demographic and financial questionnaires, and requested to report all OOPE related to their cancer treatment. Results The median total OOPE reported by 308 regional/rural participants and 119 outer metropolitan participants were A$1518 (interquartile range (IQR): A$581-A$3769) and A$2855 (IQR: A$958-A$7142) respectively. Participants most likely to experience higher total OOPE were younger than 65 years of age, male, resided in the outer metropolitan area, worked prior to diagnosis, had private health insurance, were in a relationship, and underwent surgery. Multivariate analysis of regional/rural participants revealed that receiving care at a rural cancer centre was associated with significantly lower non-medical OOPE (estimated mean A$805, 95% confidence interval (CI): A$735-A$875, P=0.038; compared with other rural participants (A$1347, 95% CI: A$743-A$1951, P<0.001)). Conclusion The cancer patients who participated in this study experienced variation in OOPE, with outer metropolitan participants reporting higher OOPE compared with their regional/rural counterparts. There is a need for cost transparency and access to care close to home, so that patients can make informed choices about where to receive their care. What is known about the topic? In recent years, OOPE for health care in general and cancer in particular have been widely debated by consumers and not-for-profit organisations; the topic has attracted much political attention because it affects both equity and access to care and has wider financial implications for the community. Research studies and reports from both consumer organisations and a Ministerial Advisory Committee found that cancer patients can face exorbitant out-of-pocket costs, and that individuals with private health insurance and those with prostate and breast cancer reported higher costs. In Western Australia, a cancer centre providing comprehensive cancer care was established in the second most populous region to ameliorate the high costs for travel and accommodation that regional cancer patients are known to experience. What does this paper add? This study is unique because it collected detailed cost information from patients and reports on the OOPE of regional/rural and outer metropolitan Western Australian patients receiving care for one of the four most common cancers; it therefore offers novel insight into the experiences of these groups. This study demonstrates that outer metropolitan cancer patients are experiencing much higher OOPE compared with regional/rural cancer patients. Additionally, regional/rural study participants who accessed a Regional Cancer Centre experienced significantly lower non-medical OOPE, compared with regional/rural study participants receiving care elsewhere. What are the implications for practitioners? First, there is a need for improved communication of OOPE to minimise costs to the patient, for example, by facilitating access to local cancer care. Health service providers and insurance companies can improve cost transparency for cancer patients by making this information more readily available, allowing patients to make informed financial choices about where to seek care. Second, the needs of working patients deserve specific attention. These patients face significant work uncertainty and additional distress following a cancer diagnosis.


Subject(s)
Health Expenditures , Neoplasms , Adult , Australia , Cross-Sectional Studies , Humans , Male , Rural Population , Western Australia
5.
Aust J Rural Health ; 28(6): 588-602, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33382474

ABSTRACT

OBJECTIVE: The aim of this qualitative analysis was to determine patients' perceptions of the impact of cancer-related costs. DESIGN: A qualitative inductive content analysis of the comment sections of surveys completed by participants in a cross-sectional study of cancer-related expenses. SETTING: Residents of 4 regional/rural and 2 outer metropolitan areas in Western Australia. PARTICIPANTS: Adults diagnosed with breast, prostate, colorectal or lung cancer participated in the study between 1 April 2014 and 31 April 2017. MAIN OUTCOME MEASURES: This study identified the key factors contributing to the cost experiences reported by the participants. RESULTS: Participant comments were organised into 4 main categories perceived to incorporate the key factors contributing to the cost experiences reported by 300 participants: 1) health care system factors (access to care in the public or private sector, availability of services close to home, gap payments, cost of travel) 2) financial factors (impact of cancer on employment, ability to work, and career; and strategies for improving financial difficulties) 3) social and community support provided by the government and not-for-profit organisations and 4) understanding of the health care system. CONCLUSION: There is a need for cost transparency, initiatives for no- or low-fee billing providers, access to care close to home, development of financial assistance schemes and return to work programs to alleviate the financial hardship experienced by cancer patients and their families.


Subject(s)
Health Expenditures , Neoplasms , Adult , Cost of Illness , Cross-Sectional Studies , Health Services Accessibility , Humans , Neoplasms/economics , Rural Population , Western Australia
6.
Mymensingh Med J ; 29(2): 325-336, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32506086

ABSTRACT

Pereinatal asphyxia is one of the most important complications related with the process of birth and this complications affect not only the brain but also many other organs. The purpose of this cross sectional study is to compare the role of craniosonogram and CT scan of the brain to delineate the cerebral pathology in respondent of preterm and term infant and to assess the Kappa test for agreement. This study was carried out in the department of Radiology & Imaging of Mymensingh Medical College Hospital, during the period of July 2015 to June 2017. A total number of 40 neonates clinically diagnosed as perinatal asphyxia referred for Craniosonogram and Computed tomography (CT) were included in this study. The test of agreement of USG in detection of neonatal cerebral pathology was calculated. Male to female ratio was 1:1.4. More than half (55.0%) patients were preterm age. The mean birth weight was found 2.3±0.6 kg and mean age was 22.7±12.7 days. Fifty five percent respondent mothers had antenatal check up and 27% had anemia, 11% had premature rupture of membrane, 9% had multiple pregnancy and 7% patient had hypertension. Cerebral pathology was found 28 and 31 cases by Craniosonogram and CT scan respectively. Germinal matrix hemorrhage/IVH (Intra ventricular hemorrhage) found 7(17.5%) in USG and 4(10.0%) in CT scan. Hypoxic ischaemic changes with mild ventriculomegaly observed 5(12.5%) in USG and 7(17.5%) in CT scan. Hypoxic ischaemic change found 4(10.0%) in USG and 5(12.5%) in CT scan. In USG evaluation of 28 patients having cerebral pathology & 16(72.7%) had in preterm group and 12(66.7%) in term group. In CT scan of brain 31 patients with cerebral pathology & 15(37.5%) in preterm group and 16(40.0%) in term group. CT scan found cerebral pathology 77.5% (31/40) cases and USG found 70.0% (28/40), with Kappa value was 0.551, which indicates that fair agreement between USG and CT scan for detection of cerebral pathology in respondent. Craniosonogram is a useful method in all neonates specially preterm to see the CNS complication of perinatal asphyxia.


Subject(s)
Asphyxia Neonatorum , Asphyxia , Adolescent , Adult , Brain , Child , Cross-Sectional Studies , Female , Humans , Infant , Infant, Newborn , Male , Pregnancy , Tomography, X-Ray Computed , Young Adult
8.
Support Care Cancer ; 26(10): 3543-3552, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29704109

ABSTRACT

PURPOSE: Out-of-pocket expenses (OOPE) can have a significant impact on patients' experiences of cancer treatment. This cross-sectional study sought to quantify the OOPEs experienced by rural cancer patients in Western Australia (WA), and determine factors that contributed to higher OOPE. METHODS: Four hundred people diagnosed with breast, lung, colorectal or prostate cancer who resided in selected rural regions of WA were recruited through the WA Cancer Registry and contacted at least 3 months after diagnosis to report the medical OOPE (such as surgery or chemotherapy, supportive care, medication and tests) and non-medical OOPE (such as travel costs, new clothing and utilities) they had experienced as a result of accessing and receiving treatment. Bootstrapped t tests identified demographic, financial and treatment-related factors to include in multivariate analysis, performed using log-linked generalised linear models with gamma distribution. RESULTS: After a median 21 weeks post-diagnosis, participants experienced an average OOPE of AU$2179 (bootstrapped 95% confidence interval $1873-$2518), and 45 (11%) spent more than 10% of their household income on these expenses. Participants likely to experience higher total OOPE were younger than 65 years (p = 0.008), resided outside the South West region (p = 0.007) and had private health insurance (PHI) (p < 0.001). CONCLUSIONS: Rural WA cancer patients experience significant OOPE following their diagnosis. The impact these expenses have on patient wellbeing and their treatment decisions need to be further explored.


Subject(s)
Neoplasms/economics , Neoplasms/epidemiology , Rural Population , Adult , Aged , Aged, 80 and over , Cross-Sectional Studies , Female , Health Expenditures/statistics & numerical data , Humans , Insurance, Health/economics , Insurance, Health/statistics & numerical data , Male , Middle Aged , Registries , Rural Population/statistics & numerical data , Socioeconomic Factors , Western Australia/epidemiology
9.
Med Sci Monit ; 24: 582-589, 2018 Jan 29.
Article in English | MEDLINE | ID: mdl-29377878

ABSTRACT

BACKGROUND Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and guide sheath (EBUS-GS) are gaining popularity for diagnosis and staging of lung cancer compared to CT-guided transthoracic needle aspiration (CT-TTNA), blind fiber-optic bronchoscopy, and mediastinoscopy. This paper aimed to examine predictors of higher costs for diagnosing and staging lung cancer, and to assess the effect of EBUS techniques on hospital cost. MATERIAL AND METHODS Hospital costs for diagnosis and staging of new primary lung cancer patients presenting in 2007-2008 and 2010-2011 were reviewed retrospectively. Multiple linear regression was used to determine relationships with hospital cost. RESULTS We reviewed 560 lung cancer patient records; 100 EBUS procedures were performed on 90 patients. Higher hospital costs were associated with: EBUS-TBNA performed (p<0.0001); increasing inpatient length of stay (p<0.0001); increasing number of other surgical/diagnostic procedures (p<0.0001); whether the date of management decision fell within an inpatient visit (p<0.0001); and if the patient did not have a CT-TTNA, then costs increased as the number of imaging events increased (interaction p<0.0001). Cohort was not significantly related to cost. Location of the procedure (outside vs. inside theater) was a predictor of lower one-day EBUS costs (p<0.0001). Cost modelling revealed potential cost saving of $1506 per EBUS patient if all EBUS procedures were performed outside rather than in the theater ($66,259 per annum). CONCLUSIONS EBUS-TBNA only was an independent predictor of higher cost for diagnosis and staging of lung cancer. Performing EBUS outside compared to in the theater may lower costs for one-day procedures; potential future savings are considerable if more EBUS procedures could be performed outside the operating theater.


Subject(s)
Bronchoscopy/economics , Costs and Cost Analysis , Endosonography/economics , Lung Neoplasms/diagnosis , Lung Neoplasms/pathology , Cohort Studies , Hospital Costs , Humans , Inpatients , Linear Models , Lung Neoplasms/economics , Models, Theoretical , Neoplasm Staging
10.
Exp Hematol ; 46: 70-82.e10, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27751872

ABSTRACT

Erythropoiesis is controlled principally through erythropoietin (Epo) receptor signaling, which involves Janus kinase 2 (JAK2) and Lyn tyrosine kinase, both of which are important for regulating red blood cell (RBC) development. Negative regulation of Lyn involves C-Src kinase (Csk)-mediated phosphorylation of its C-terminal tyrosine, which is facilitated by the transmembrane adaptor Csk-binding protein (Cbp). Although Cbp has significant functions in controlling Lyn levels and activity in erythroid cells in vitro, its importance to primary erythroid cell development and signaling has remained unclear. To address this, we assessed the consequence of loss of Cbp on the erythroid compartment in vivo and whether Epo-responsive cells isolated from Cbp-knockout mice exhibited altered signaling. Our data show that male Cbp-/- mice display a modest but significant alteration to late erythroid development in bone marrow with evidence of increased erythrocytes in the spleen, whereas female Cbp-/- mice exhibit a moderate elevation in early erythroid progenitors (not seen in male mice) that does not influence the later steps in RBC development. In isolated primary erythroid cells and cell lines generated from Cbp-/- mice, survival signaling through Lyn/Akt/FoxO3 was elevated, resulting in sustained viability during differentiation. The high Akt activity disrupted GAB2/SHP-2 feedback inhibition of Lyn; however, the elevated Lyn activity also increased inhibitory signaling via SHP-1 to restrict the Erk1/2 pathway. Interestingly, whereas loss of Cbp led to mild changes to late RBC development in male mice, this was not apparent in female Cbp-/- mice, possibly due to their elevated estrogen, which is known to facilitate early progenitor self-renewal.


Subject(s)
Cell Differentiation , Erythroid Cells/cytology , Erythroid Cells/metabolism , Erythropoiesis , Membrane Proteins/metabolism , Phosphoproteins/metabolism , src-Family Kinases/metabolism , Animals , Cell Differentiation/genetics , Cell Line , Cell Survival/genetics , Enzyme Activation , Female , Forkhead Box Protein O3/metabolism , Male , Membrane Proteins/genetics , Mice , Mice, Knockout , Models, Biological , Phosphoproteins/genetics , Protein Binding , Protein Tyrosine Phosphatase, Non-Receptor Type 6/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction
11.
BMC Cancer ; 16: 44, 2016 Jan 28.
Article in English | MEDLINE | ID: mdl-26822160

ABSTRACT

BACKGROUND: Utilisation of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and guide sheath (EBUS-GS) for diagnosis and staging of lung cancer is gaining popularity, however, its impact on clinical practice is unclear. This study aimed to determine the impact of the introduction of endobronchial ultrasound-guided procedures (EBUS) on time to management decision for lung cancer patients, and on the utilisation of other invasive diagnostic modalities, including CT-guided trans-thoracic needle aspiration (CT-TTNA), bronchoscopy, and mediastinoscopy. METHODS: Hospital records of new primary lung cancer patients presenting in 2007 and 2008 (Pre-EBUS cohort) and in 2010 and 2011 (Post-EBUS cohort) were reviewed retrospectively. RESULTS: The Pre-EBUS cohort included 234 patients. Of the 326 patients in the Post-EBUS cohort, 90 had an EBUS procedure (EBUS-TBNA for 19.0% and EBUS-GS for 10.4% of cases). The number of CT-TTNAs and bronchoscopies decreased following the introduction of EBUS (p = 0.015 and p < 0.001 respectively). Of 162 CT-TTNAs, 59 (36%) resulted in complications compared to 1 complication each for bronchoscopy and EBUS-GS, and no complications from EBUS-TBNA. Fewer complications occurred overall in the Post-EBUS cohort compared to the Pre-EBUS cohort (p = 0.0264). The median time to management decision was 17 days (IQR 24) for the Pre-EBUS and 13 days (IQR 21) for the Post-EBUS cohort (p = 0.07). Within the Post-EBUS cohort, median time to management decision was longer for the EBUS group (n = 90) than the Non-EBUS group (17 days (IQR 29) vs. 10 days (IQR 10), p < 0.001). For half of EBUS-TBNA patients (n = 28, 50.0%) and EBUS-GS patients (n = 14, 50.0 %), EBUS alone provided sufficient diagnostic and/or staging information; these patients had median time to management decision of 10 days. Regression analysis revealed that the number of imaging events, inpatient, and outpatient visits were significant predictors of time to management decision of >28 days; EBUS was not a predictor of time to management decision. CONCLUSIONS: The introduction of EBUS led to fewer CT-TTNAs and bronchoscopies and did not impact on the time to management decision. EBUS-TBNA or EBUS-GS alone provided sufficient information for diagnosis and/or regional staging in half of the lung cancer patients referred for this investigation.


Subject(s)
Endoscopic Ultrasound-Guided Fine Needle Aspiration , Lung Neoplasms/diagnosis , Lung/pathology , Lymphatic Metastasis/diagnosis , Aged , Aged, 80 and over , Biopsy, Fine-Needle , Bronchoscopy , Female , Humans , Lung/diagnostic imaging , Lung Neoplasms/pathology , Lymph Nodes/diagnostic imaging , Lymph Nodes/pathology , Lymphatic Metastasis/diagnostic imaging , Lymphatic Metastasis/pathology , Male , Mediastinoscopy , Middle Aged , Neoplasm Staging , Tomography, X-Ray Computed
12.
Adv Protein Chem Struct Biol ; 98: 93-119, 2015.
Article in English | MEDLINE | ID: mdl-25819277

ABSTRACT

Among the most common nanoparticulate systems, the polymeric nanocarriers have a number of key benefits, which give a great choice of delivery platforms. Nevertheless, polymeric nanoparticles possess some limitations that include use of toxic solvents in the production process, polymer degradation, drug leakage outside the diseased tissue, and polymer cytotoxicity. The combination of polymers of biological and synthetic origin is an appealing modern strategy for the production of novel nanocarriers with unprecedented properties. Proteins' interface can play an important role in determining bioactivity and toxicity and gives perspective for future development of the polymer-based nanoparticles. The design of hybrid constructs composed of synthetic polymer and biological molecules such as proteins can be considered as a straightforward tool to integrate a broad spectrum of properties and biofunctions into a single device. This review discusses hybrid protein-synthetic polymer nanoparticles with different structures and levels in complexity and functionality, in view of their applications as drug delivery systems.


Subject(s)
Drug Delivery Systems/methods , Nanoparticles/chemistry , Polyesters/chemistry , Polyethylene Glycols/chemistry , Polyglutamic Acid/chemistry , Proteins/chemistry , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Doxorubicin/chemistry , Doxorubicin/pharmacology , Humans , Micelles , Nanoparticles/ultrastructure , Static Electricity
13.
Med J Aust ; 202(3): 144-7, 2015 Feb 16.
Article in English | MEDLINE | ID: mdl-25669477

ABSTRACT

OBJECTIVE: To develop a peer-review model for assessment and quality improvement of cancer multidisciplinary teams (MDTs) and qualitatively assess its feasibility and acceptability in Australia. DESIGN, SETTING AND PARTICIPANTS: A peer-review methodology was developed, based on the United Kingdom's National Health Service peer-review model and a comprehensive literature review. This was pilot tested in three mature MDTs in different settings. Semi-structured interviews were conducted between December 2012 and July 2013 with all five peer reviewers and 17 MDT members. Thematic analysis was undertaken using a framework approach. RESULTS: Peer reviewers and MDT members found the process reasonable, constructive and useful; however, those involved in the preparation for the review found it time-consuming. Most MDT members considered the final report accurate and reflective of their service. Recommendations in the report were met with mixed reactions: several MDT members perceived some recommendations to be particularly relevant, while others viewed the same recommendations as impractical or of limited value. Many participants were unsure if recommendations would be fully implemented. The majority saw value in the process and expressed support for its implementation locally and nationally; however, feedback suggests the most appropriate format is yet to be established. CONCLUSIONS: Peer review of cancer MDTs is feasible and acceptable. We describe valuable lessons learnt and recognise that further development of the proposed peer-review model and national benchmarking of MDTs against established outcome measures is required if this process is to be widely implemented.


Subject(s)
Neoplasms/therapy , Patient Care Team , Peer Review, Health Care , Benchmarking , Clinical Governance , Feasibility Studies , Feedback , Humans , Motivation , Outcome Assessment, Health Care , Pilot Projects , Practice Guidelines as Topic , Qualitative Research , Staff Development , Western Australia
14.
Biochem J ; 459(3): 455-66, 2014 May 01.
Article in English | MEDLINE | ID: mdl-24552351

ABSTRACT

Erythroid homoeostasis is primarily controlled by Epo (erythropoietin) receptor signalling; however, the Lyn tyrosine kinase plays an important subsidiary role in regulating the erythroid compartment. Nonetheless, specific erythroid pathways that require Lyn activity and their biological significance remain unclear. To address this, we asked what consequence loss of Lyn had on the ex vivo expansion and maturation of splenic erythroid progenitors and Epo receptor signalling. Pharmacological inhibition of Lyn with PP2 inhibited the survival of terminally differentiated erythroblasts. Less committed erythroid progenitors expanded well, whereas early splenic Lyn(-/-) erythroblasts had attenuated ex vivo expansion, and late stage Lyn(-/-) erythroblasts were retarded in completing morphological maturation ex vivo. Furthermore, immortalized Lyn(-/-) erythroblasts were slower growing, less viable and inhibited in their differentiation. Signalling studies showed that Lyn was required for both positive GAB2/Akt/FoxO3 (forkhead box O3) survival signals as well as negative feedback of JAK2 (Janus kinase 2)/STAT5 (signal transducer and activator of transcription 5) and ERK1/2 (extracellular-signal-regulated kinase 1/2) signals via SHP-1 (Src homology 2 domain-containing protein tyrosine phosphatase 1). During differentiation, Lyn controls survival and cell cycle exit as demonstrated by reduced STAT5 and FoxO3/GSKα/ß (glycogen synthase kinase α/ß) phosphorylation and diminished p27(Kip1) induction in Lyn-deficient erythroblasts. Lyn deficiency alters the balance of pro- and anti-apoptotic molecules (BAD and BclXL), thereby reducing survival and preventing cell cycle exit. Consequently, Lyn facilitates normal erythrocyte production by influencing different stages of erythroid progenitor expansion, and mature cell development and survival signalling.


Subject(s)
Apoptosis Regulatory Proteins/metabolism , Erythroblasts/metabolism , Erythroid Precursor Cells/metabolism , Erythropoiesis , Receptors, Erythropoietin/metabolism , Signal Transduction , src-Family Kinases/metabolism , Animals , Apoptosis Regulatory Proteins/agonists , Apoptosis Regulatory Proteins/antagonists & inhibitors , Cell Differentiation/drug effects , Cell Line, Transformed , Cell Proliferation/drug effects , Cell Survival/drug effects , Cells, Cultured , Embryo, Mammalian/cytology , Erythroblasts/cytology , Erythroblasts/drug effects , Erythroid Precursor Cells/cytology , Erythroid Precursor Cells/drug effects , Erythropoiesis/drug effects , Erythropoietin/pharmacology , Hematinics/pharmacology , Mice , Mice, Inbred C57BL , Mice, Mutant Strains , Protein Kinase Inhibitors/pharmacology , Pyrimidines/pharmacology , Receptors, Erythropoietin/agonists , Signal Transduction/drug effects , Spleen/cytology , src-Family Kinases/antagonists & inhibitors , src-Family Kinases/genetics
15.
Blood ; 122(2): 262-71, 2013 Jul 11.
Article in English | MEDLINE | ID: mdl-23692855

ABSTRACT

Lyn is involved in erythropoietin (Epo)-receptor signaling and erythroid homeostasis. Downstream pathways influenced following Lyn activation and their significance to erythropoiesis remain unclear. To address this, we assessed a gain-of-function Lyn mutation (Lyn(up/up)) on erythropoiesis and Epo receptor signaling. Adult Lyn(up/up) mice were anemic, with dysmorphic red cells (spherocyte-like, acanthocytes) in their circulation, indicative of hemolytic anemia and resembling the human disorder chorea acanthocytosis. Heterozygous Lyn(+/up) mice became increasingly anemic with age, indicating that the mutation was dominant. In an attempt to overcome this anemia, extramedullary erythropoiesis was activated. As the mice aged, the levels of different immature erythroid populations changed, indicating compensatory mechanisms to produce more erythrocytes were dynamic. Changes in Epo signaling were observed in Lyn(+/up) erythroid cell lines and primary CD71(+) Lyn(up/up) erythroblasts, including significant alterations to the phosphorylation of Lyn, the Epo receptor, Janus kinase 2, Signal Transducer and Action of Transcription-5, GRB2-associated-binding protein-2, Akt, and Forkhead box O3. As a consequence of altered Lyn signaling, Lyn(+/up) cells remained viable in the absence of Epo but displayed delayed Epo-induced differentiation. These data demonstrate that Lyn gene dosage and activity are critical for normal erythropoiesis; constitutively active Lyn alters Epo signaling, which in turn produces erythroid defects.


Subject(s)
Anemia, Hemolytic/genetics , Anemia, Hemolytic/metabolism , Erythropoiesis/physiology , Receptors, Erythropoietin/metabolism , Signal Transduction , src-Family Kinases/genetics , Adaptor Proteins, Signal Transducing , Anemia, Hemolytic/blood , Animals , Bone Marrow/metabolism , Cell Differentiation/drug effects , Cell Differentiation/genetics , Cell Line , Enzyme Activation/genetics , Erythrocyte Indices , Erythrocytes/pathology , Erythroid Precursor Cells/cytology , Erythroid Precursor Cells/metabolism , Erythropoietin/pharmacology , Janus Kinase 2/metabolism , Mice , Mice, Transgenic , Phosphoproteins/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Spleen/metabolism , src-Family Kinases/metabolism
16.
Biochem J ; 442(3): 611-20, 2012 Mar 15.
Article in English | MEDLINE | ID: mdl-22364282

ABSTRACT

The tyrosine kinase Lyn is involved in oncogenic signalling in several leukaemias and solid tumours, and we have previously identified a pathway centred on Cbp [Csk (C-terminal Src kinase)-binding protein] that mediates both enzymatic inactivation, as well as proteasomal degradation of Lyn via phosphorylation-dependent recruitment of Csk (responsible for phosphorylating the inhibitory C-terminal tyrosine of Lyn) and SOCS1 (suppressor of cytokine signalling 1; an E3 ubiquitin ligase). In the present study we show that fusing specific functional motifs of Cbp and domains of SOCS1 together generates a novel molecule capable of directing the proteasomal degradation of Lyn. We have characterized the binding of pY (phospho-tyrosine) motifs of Cbp to SFK (Src-family kinase) SH2 (Src homology 2) domains, identifying those with high affinity and specificity for the SH2 domain of Lyn and that are preferred substrates of active Lyn. We then fused them to the SB (SOCS box) of SOCS1 to facilitate interaction with the ubiquitination-promoting elongin B/C complex. As an eGFP (enhanced green fluorescent protein) fusion, these proteins can direct the polyubiquitination and proteasomal degradation of active Lyn. Expressing this fusion protein in DU145 cancer cells (but not LNCaP or MCF-7 cells), that require Lyn signalling for survival, promotes loss of Lyn, loss of caspase 3, appearance of an apoptotic morphology and failure to survive/expand. These findings show how functional domains of Cbp and SOCS1 can be fused together to generate molecules capable of inhibiting the growth of cancer cells that express high levels of active Lyn.


Subject(s)
Membrane Proteins/genetics , Suppressor of Cytokine Signaling Proteins/metabolism , src-Family Kinases/metabolism , Animals , Binding Sites , COS Cells , Chlorocebus aethiops , Membrane Proteins/metabolism , Mice , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Suppressor of Cytokine Signaling Proteins/chemistry , Suppressor of Cytokine Signaling Proteins/genetics , Tumor Cells, Cultured , src-Family Kinases/genetics
17.
Adv Protein Chem Struct Biol ; 80: 205-52, 2010.
Article in English | MEDLINE | ID: mdl-21109221

ABSTRACT

The use of proteins as a substrate in the fabrication of micro- and nanoparticulate systems has attracted the interest of scientists, manufactures, and consumers. Albumin-derived particles were commercialized as contrast agents or anticancer therapeutics. Food proteins are widely used in formulated dietary products. The potential benefits of proteinaceous micro- and nanoparticles in a wide range of biomedical applications are indisputable. Protein-based particles are highly biocompatible and biodegradable structures that can impart bioadhesive properties or mediate particle uptake by specific interactions with the target cells. Currently, protein microparticles are engineered as vehicles for covalent attachment and/or encapsulation of bioactive compounds, contrast agents for magnetic resonance imaging, thermometric and oximetric imaging, sonography and optical coherence tomography, etc. Ultrasound irradiation is a versatile technique which is widely used in many and different fields as biology, biochemistry, dentistry, geography, geology, medicine, etc. It is generally recognized as an environmental friendly, cost-effective method which is easy to be scaled up. Currently, it is mainly applied for homogenization, drilling, cleaning, etc. in industry, as well for noninvasive scanning of the human body, treatment of muscle strains, dissolution of blood clots, and cancer therapy. Proteinaceous micro- and nanocapsules could be easily produced in a one-step process by applying ultrasound to an aqueous protein solution. The origin of this process is in the chemical changes, for example, sulfhydryl groups oxidation, that takes place as a result of acoustically generated cavitation. Partial denaturation of the protein most probably occurs which makes the hydrophobic interactions dominant and also responsible for the formation of stable capsules. This chapter aims to present the current state-of-the-art in the field of sonochemically produced protein micro- and nanocapsules, paying special attention to the proposed mechanisms for their formation, the factors that influence the capsules characteristics as well to the current applications of these particles. Current challenges in the field are also outlined as, for example, the ultrasound-protein interaction and other possible aspects of the mechanism of their formation.


Subject(s)
Capsules/chemistry , Nanocapsules/chemistry , Nanotechnology , Proteins/chemistry , Ultrasonics , Contrast Media/chemistry , Humans , Serum Albumin, Bovine/chemistry
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