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Effectiveness of silver diamine fluoride versus sodium fluoride varnish combined with mother's motivational interviewing for arresting early childhood caries: a randomized clinical trial. BMC Oral Health 2023; 23:710. [PMID: 37789300 PMCID: PMC10548636 DOI: 10.1186/s12903-023-03456-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Accepted: 09/25/2023] [Indexed: 10/05/2023] Open
Abstract
BACKGROUND Silver Diamine Fluoride (SDF) has gained attention as one of the minimally invasive modalities to manage ECC although it causes black staining of treated carious lesions. A possible affordable alternative may be Sodium Fluoride (NaF) varnish combined with good oral hygiene promoted by parental Motivational Interviewing (MI). The study compared the effectiveness of 38% SDF solution and 5% NaF varnish supported by parental MI in arresting ECC. MATERIALS AND METHODS Children aged ≤ 4 years old with at least one active carious lesion (ICDAS score ≥ 3) were randomly assigned to treatment by a single application of 38% SDF solution or a single application of 5% NaF varnish supported by two MI sessions for mothers at baseline and after three months. Chi-Squared test was used to compare groups and multilevel logistic regression analysis was used to assess the effect of the interventions on ECC arrest adjusting for confounders. The interaction between the type of intervention and baseline lesion severity, moderate (ICDAS 3/4) or advanced (ICDAS 5/6), was also assessed. RESULTS The study included 165 children with 949 active lesions. After 6 months, there were no significant differences between SDF and NaF/MI groups in overall caries arrest (63.7% and 58.1%, p = 0.08), and in moderate lesions (72.9% and 69.6%, p = 0.52). However, in advanced lesions, the arrest rate was significantly higher in the SDF than the NaF/ MI group (60.3% and 50.0%, P = 0.01). Multilevel multiple logistic regression showed no significant differences between the interventions (AOR = 1.56, P = 0.27) with significant interaction between the intervention and baseline lesion severity (p < 0.001). Moderate lesions treated with SDF (AOR = 3.69, P = 0.008) or NaF/MI (AOR = 3.32, P < 0.001) had significantly higher odds of arrest than advanced lesions treated with NaF/ MI with no difference between advanced lesions treated with SDF or NaF/ MI (AOR = 1.85, P = 0.155) in arrest rate. CONCLUSION NaF/ MI can be an alternative to SDF in arresting advanced and moderate ECC lesions without staining with stronger effect on moderate lesions (ICDAS 3/4). TRIAL REGISTRATION The trial was retrospectively registered at clinicaltrial.gov registry (#NCT05761041) on 9/3/2023.
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Sexual health risk indicators and their associations with caries status and gingival health of adolescents resident in sub-urban South-West Nigeria. AAS Open Res 2022. [DOI: 10.12688/aasopenres.13301.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: Adolescents are at high risk of poor sexual and oral health. We investigated for sexual risk factors associated with caries experience and gingival health among adolescents in Nigeria. Methods: This cross-sectional study collected data from 10-19-year-old adolescents in Ile-Ife, South-West Nigeria through a household survey conducted between December 2018 and January 2019. Information collected included age; sex; socioeconomic status; sexual practices (vaginal, oral, anal sex); sexual (transactional sex, multiple sex partners, condom use at last sexual intercourse) and oral health (frequency of tooth brushing, use of fluoridated toothpaste, dental service utilization in the last 12 months, consumption of refined carbohydrates in-between meals) risk behaviors; caries experience; and gingival health. Logistic regression was used to determine associations between explanatory variables (sexual and oral health risk behaviors) and outcome variables (caries experience and gingivitis). Results: There were no significant associations between caries experience and history of sexual intercourse (OR:1.00); condom use at last sex act (OR:0.68); and having one (OR:2.27) or more sexual partners. Also, there was no significant association between moderate/severe gingivitis and a history of anal (OR:2.96), oral (OR:2.69), or vaginal (OR:1.40) sex; and a report of having one (OR:1.71) or more (OR:2.57) sex partners. Conclusions: Some sexual health risk indicators insignificantly increase the risk for caries and moderate/severe gingivitis. Screening for sexual risk behaviors during dental care may be a suitable wellness programs approach for adolescents.
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Parenting practices and oral health behaviors of children in rural Egypt: gender differences in a household survey. BMC Oral Health 2022; 22:17. [PMID: 35081943 PMCID: PMC8793182 DOI: 10.1186/s12903-022-02054-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 01/17/2022] [Indexed: 12/02/2022] Open
Abstract
Background Parenting practices influence children’s health and development. The current study aimed at assessing gender differences in children’s perception of the parenting practices of both parents, and in the association between children’s oral health behaviors and parenting practices. Methods A cross-sectional household survey of 6–12 year old children was conducted in a rural area in Northwestern Egypt in 2019. Clinical examination assessed caries and gingivitis. The Alabama Parenting Questionnaire assessed parenting practices in five domains (positive parenting, involvement, inconsistent disciplining, poor monitoring and corporal punishment) and the World Health Organization questionnaire assessed oral health behaviors including sugar consumption and daily toothbrushing. Sugar consumption was the dependent variable in linear regression and daily toothbrushing was the dependent variable in logistic regression. Parenting practices were the explanatory variables adjusting for confounders. Effect modification by child gender was assessed. Results The response rate was 94.1% (n = 433), mean age = 9.9 years, 44.1% boys, 17.8% with daily toothbrushing and mean sugar consumption score = 3.4/8. Girls perceived more mothers’ positive parenting than boys (mean = 14.15 and 13.46) and boys perceived more poor monitoring and corporal punishment. Boys and girls differed in the association between sugar consumption and fathers’ inconsistent disciplining, poor monitoring (P = 0.004 and 0.02) and mothers’ corporal punishment (P = 0.02), and also daily toothbrushing and mothers’ involvement, positive parenting (P = 0.05 and 0.02), fathers’ positive parenting (P = 0.02), mothers’ inconsistent discipling and poor monitoring (P = 0.01 and 0.04). Conclusions There were differences between boys and girls in perceiving mothers’ and fathers’ parenting practices and in the association between these parenting practices and toothbrushing and sugar consumption. Supplementary Information The online version contains supplementary material available at 10.1186/s12903-022-02054-z.
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Using mHealth to promote parents' brushing of preschool children's teeth: a protocol for a randomized factorial trial using the Multi-phase Optimization Strategy (MOST). Trials 2022; 23:17. [PMID: 34991701 PMCID: PMC8733768 DOI: 10.1186/s13063-021-05931-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 12/09/2021] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Early childhood caries is a highly prevalent disease affecting young children. Parental brushing of children's teeth is recommended during preschool years. Interventions to promote parental brushing of children's teeth are assessed as a package in randomized clinical trials and the efficacy of separate components is not known. METHODS AND ANALYSIS The aim of this study is to develop an optimized behavior modification intervention to increase parents' brushing of their pre-school children's teeth using the multi-phase optimization strategy (MOST) guided by the Theory of Planned Behavior. Behavior change will be assessed by the percent reduction in children's dental plaque index after 6 months and parents reporting of toothbrushing frequency. Two phases of MOST will be carried out. First, the preparation phase comprises the development of a conceptual framework, identifying candidate components, conducting a feasibility pilot study to assess the acceptability and the design features of three intervention components (motivational interviewing (MI), and two mobile health (mHealth) components: oral health promotion messages and storytelling videos delivered using WhatsApp messenger) in addition to setting an optimization objective. Second, the optimization phase constitutes a factorial trial assessing the three intervention components and developing the intervention by selecting the most effective components within the optimization constraint. Each component will be set at two levels: yes (the intervention is applied) and no (the intervention is not applied). A linear regression model will be used to assess the effect of the intervention components on the percent reduction in dental plaque index (primary outcome measure). The secondary outcome measure is the change in the frequency of parents' brushing of the child's teeth. The combination of components making up the new optimized intervention will be selected. DISCUSSION This will be the first study to apply the MOST framework in the field of dentistry. The results of this study can guide the development of an optimized behavior modification interventions using mHealth and MI. TRIAL REGISTRATION ClinicalTrials.gov, NCT04923581, Registered 11 June 2021.
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Association between mental health, caries experience and gingival health of adolescents in sub-urban Nigeria. BMC Oral Health 2021; 21:223. [PMID: 33931069 PMCID: PMC8086282 DOI: 10.1186/s12903-021-01589-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 04/22/2021] [Indexed: 11/10/2022] Open
Abstract
Background This study assessed the association of mental health problems and risk indicators of mental health problems with caries experience and moderate/severe gingivitis in adolescents. Methods A cross-sectional household survey was conducted in Osun State, Nigeria. Data collected from 10 to 19-years-old adolescents between December 2018 and January 2019 were sociodemographic variables (age, sex, socioeconomic status); oral health indicators (tooth brushing, use of fluoridated toothpaste, consumption of refined carbohydrates in-between-meals, dental services utilization, dental anxiety and plaque); mental health indicators (smoking habits, intake of alcohol and use of psychoactive drugs) and mental health problems (low and high). Gingival health (healthy gingiva/mild gingivitis versus moderate/severe gingivitis) and caries experience (present or absent) were also assessed. A series of five logistic regression models were constructed to determine the association between presence of caries experience and presence of moderate/severe gingivitis) with blocks of independent variables. The blocks were: model 1—sociodemographic factors; model 2—oral health indicators; model 3—mental health indicators and model 4—mental health problems. Model 5 included all factors from models 1 to 4. Results There were 1234 adolescents with a mean (SD) age of 14.6 (2.7) years. Also, 21.1% of participants had high risk of mental health problems, 3.7% had caries experience, and 8.1% had moderate/severe gingivitis. Model 5 had the best fit for the two dependent variables. The use of psychoactive substances (AOR 2.67; 95% CI 1.14, 6.26) was associated with significantly higher odds of caries experience. The frequent consumption of refined carbohydrates in-between-meals (AOR: 0.41; 95% CI 0.25, 0.66) and severe dental anxiety (AOR0.48; 95% CI 0.23, 0.99) were associated with significantly lower odds of moderate/severe gingivitis. Plaque was associated with significant higher odds of moderate/severe gingivitis (AOR 13.50; 95% CI 8.66, 21.04). High risk of mental health problems was not significantly associated with caries experience (AOR 1.84; 95% CI 0.97, 3.49) or moderate/severe gingivitis (AOR 0.80; 95% CI 0.45, 1.44). Conclusion The association between mental problems and risk indicators with oral diseases in Nigerian adolescents indicates a need for integrated mental and oral health care to improve the wellbeing of adolescents.
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Children post liver transplantation hospitalized with fever are at a high risk for bacterial infections. Transpl Infect Dis 2016; 18:333-40. [DOI: 10.1111/tid.12528] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Revised: 12/09/2015] [Accepted: 01/10/2016] [Indexed: 12/01/2022]
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Papillary-cystic variant of acinic cell carcinoma of the salivary gland diagnosed by fine needle aspiration biopsy. A case report. Acta Cytol 2000; 44:1073-6. [PMID: 11127737 DOI: 10.1159/000328600] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Fine needle aspiration (FNA) biopsy is reliably used to classify most conditions involving the salivary glands. It is useful for establishing, or at least suggesting, the diagnosis in unusual cases or narrowing the differential diagnosis. CASE A 25-year-old male presented with a slowly enlarging mass of the left parotid. FNA biopsy of the parotid gland was performed, and a diagnosis of papillary-cystic variant of acinic cell carcinoma was suggested. The patient underwent incomplete resection of the lesion, which was interpreted as acinic cell carcinoma. CONCLUSION Papillary-cystic variant of acinic cell carcinoma is rarely seen, especially in young people. FNA biopsy is a useful diagnostic procedure that can help diagnose this relatively uncommon type of salivary gland neoplasm and guide its management.
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Cyclin D1, retinoblastoma, p53, and Her2/neu protein expression in preinvasive breast pathologies: correlation with vascularity. Pathobiology 2000; 68:129-36. [PMID: 11174070 DOI: 10.1159/000055913] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES Preinvasive breast pathologies show a degree of vascularization that correlates with risk of invasion. Recently, numerous oncogenes and tumor suppressor genes have been shown to regulate neovascularization. Therefore, we examined archival tissues of preinvasive breast pathologies by immunohistochemistry for alterations in the expression of four proteins, cyclin D1, retinoblastoma (Rb), p53, and Her2/neu, known to be important in breast tumorgenesis, and correlated these data with tissue vascularity. METHODS Vascularity was determined by immunologic detection of von Willebrand factor. For carcinoma in situ (CIS) both stromal vascularity (MVD) and vascular cuffing (MCD) were determined. RESULTS We found that cyclin D1 expression was increased in usual hyperplasia (11% of cases). Atypical hyperplasia, noncomedo CIS and comedo CIS were positive in 43, 49, and 57% of cases, respectively. Changes in Rb and p53 were rare in hyperplasia but occurred in 8 and 10% of CIS, respectively. Her2/neu protein was identified rarely in atypical hyperplasia and in both noncomedo and comedo ductal CIS. Neither Rb nor Her2/neu expression correlated with vascularity. p53 immunoreactivity correlated positively with both MCD and MVD. Cyclin D1 was negatively associated with MVD. CONCLUSION These data suggest that p53 and cyclin D1 proteins may regulate the microvessel density of preinvasive breast pathologies.
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Angiogenic growth factors in preinvasive breast disease. Clin Cancer Res 1999; 5:2867-76. [PMID: 10537355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Recently, we showed that preinvasive breast pathologies, such as usual hyperplasia, atypical hyperplasia, and carcinoma in situ, have an increased vascularity when compared with normal breast tissue (S. C. Heffelfinger et al., Clinical Cancer Res., 2: 1873-1878, 1996). To understand the mechanism of this increased vascularity, we examined by immunohistochemistry each of these pathological lesions for the expression of angiogenic growth factors. These studies showed that normal breast tissue contains numerous angiogenic agents, particularly vascular endothelial cell growth factor and basic fibroblast growth factor. At the transition from normal epithelium to proliferative breast disease, insulin-like growth factor (IGF) II expression was increased, primarily in the stroma and infiltrating leukocytes. However, among proliferative tissues, IGF I decreased with increasing vascularity. Finally, both epithelial vascular endothelial growth factor and epithelial and leukocytic platelet-derived endothelial cell growth factor increased at the transition to carcinoma in situ, whereas stromal and leukocytic basic fibroblast growth factor were elevated only in invasive carcinoma. Therefore, during histological progression there is also a complex progression of angiogenic growth factors. For CIS, two forms of vascularity are found: stromal microvascular density (MVD), and vascularity associated with the epithelial basement membrane (vascular score). There was 35% discordance between these two measurement systems. Among carcinoma in situ cases, decreases in stromal IGF II were associated with increasing vascular scores but not MVD, and increases in platelet-derived endothelial cell growth factor were associated with increasing MVD but not the vascular score. The presence of discordance and differential association with specific angiogenic agents suggests that these two forms of vascularity may be differentially regulated.
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Multilobated large B-cell lymphoma diagnosed cytologically. A case report. Acta Cytol 1999; 43:847-52. [PMID: 10518141 DOI: 10.1159/000331301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Fine needle aspiration (FNA) biopsy can be used to reliably classify most conditions involving lymph nodes or, at least, significantly reduce the differential diagnosis. CASE A 70-year-old male presented with an ulcerated mass arising from the left tonsillar fossa and involving the anterior and posterior pillars. A biopsy of the tonsillar mass performed at an outside hospital was interpreted as a large cell undifferentiated carcinoma. Subsequently the patient developed systemic lymphadenopathy. A bone scan showed intense uptake within the medial tibial plateau of the left knee. FNA biopsy of the right axillary mass was interpreted at University of Cincinnati Medical College as a large cell lymphoma, multilobated type. Histologic and immunohistochemical studies of the lymph node confirmed the presence of multilobated B-cell lymphoma. Lymphoma chemotherapy was initially successful but was discontinued due to toxicity. The patient died two months after the initial cytologic diagnosis of lymphoma. CONCLUSION Multilobated lymphomas are an unusual variant of non-Hodgkin's lymphomas (mostly B-cell type). Cytology and immunocytochemistry are useful diagnostic procedures that can help to diagnose this relatively uncommon type of lymphoma and significantly reduce the possibility of misdiagnosis.
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Abstract
OBJECTIVE To evaluate the immunohistochemical expression of a lung epithelial gene transcription factor, thyroid transcription factor-1 (TTF-1), in lung and breast carcinoma in pulmonary cytologic preparations and to correlate the results with the expression of cytokeratin 7 (CK7) and 20 (CK20). STUDY DESIGN Cell blocks of cytologic specimens were immunostained with antibodies to TTF-1, CK7 and CK20. Specimens included 41 primary lung carcinomas (21 adenocarcinomas, 8 squamous cell carcinomas and 12 small cell undifferentiated carcinomas) and 6 metastatic breast adenocarcinomas. RESULTS The lung adenocarcinomas showed nuclear reactivity for TTF-1 in 76% (16/21) of the cases and a staining combination of CK7+/CK20- in 95% (20/21) of the cases. Only one case was CK7+/CK20+. All the breast carcinomas were nonreactive to TTF-1, and all were CK7+/CK20-. The squamous cell carcinomas and small cell undifferentiated carcinomas showed TTF-1 positivity in 38% (3/8) and 83% (10/12), respectively.
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Genetic dynamics and molecular epidemiology of Salmonella typhi. MEDICAL JOURNAL OF INDONESIA 1998. [DOI: 10.13181/mji.v7isupp1.1062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Vascularity of proliferative breast disease and carcinoma in situ correlates with histological features. Clin Cancer Res 1996; 2:1873-8. [PMID: 9816143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The level of vascularity within an invasive breast carcinoma is a predictor of metastatic potential and survival. However, little is known about the vascular potential and prognostic value of angiogenesis in preinvasive breast pathology. Women with proliferative breast disease or carcinoma in situ are at increased risk of developing invasive breast cancer. This relative risk increases in correlation with defined histopathological features. We asked whether these early proliferative lesions and carcinoma in situ were capable of inducing a vascular supply. Vascularity in preinvasive archival paraffin-embedded breast tissue from 90 patients was quantified by immunohistochemical identification of vessels using anti-von Willebrand factor. Vascular scores were analyzed with respect to histopathological diagnosis, age at diagnosis, and presence of coincident invasive disease. These data indicate that: (a) the vascularity of histopathologically normal epithelium is greater in breasts containing invasive disease than in breasts lacking invasive disease; (b) simple proliferative breast disease induces a vascular supply greater than that of normal breast epithelium; and (c) vascularity increases in proportion to epithelial lesion progression and relative risk of invasion. These studies indicate that the vascularity of preinvasive breast pathology may be a clinically useful predictor of invasive breast cancer.
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Sonography of a solidified benign breast cyst. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 1996; 15:165-167. [PMID: 8622195 DOI: 10.7863/jum.1996.15.2.165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Abstract
Many proteins--including not only structural proteins, but also enzymes, hormone receptors, and other transcription factors--accumulate to much higher nuclear than cytoplasmic concentrations. Nuclear localization sequences or signals (NLSs) within their primary structures entrain specific transport of these proteins through the nuclear pore complexes. This transport process is energy-dependent, but evidence for a true active transport mechanism is not conclusive. An alternative mechanism--facilitated transport of NLS proteins followed by their intranuclear binding--has been implicated by experiments with oil-isolated nuclei. However, there has been no agreement as to a role for binding in the in vivo nuclear accumulation of NLS-containing proteins. We demonstrate herein that a prototypical NLS protein, nucleoplasmin (Np), binds within the nucleus of the living Xenopus oocyte and that this binding accounts for its nuclear accumulation.
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Is a rise in intracellular concentration of free calcium necessary or sufficient for stimulated cytoskeletal-associated actin? J Biophys Biochem Cytol 1986; 102:1459-63. [PMID: 3082894 PMCID: PMC2114170 DOI: 10.1083/jcb.102.4.1459] [Citation(s) in RCA: 101] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The addition of the calcium ionophore A23187 to rabbit neutrophils increases the amount of actin associated with the cytoskeleton regardless of the presence or absence of calcium in the incubation medium. In the presence of extracellular calcium, the effect of A23187 is biphasic with respect to concentration. The action of the ionophore is rapid, transient, and is inhibited by pertussis toxin, hyperosmolarity, and quinacrine. On the other hand, the addition of pertussis toxin or hyperosmolarity has small if any, effect on the rise in intracellular calcium produced by A23187. While quinacrine does not affect the fMet-Leu-Phe-induced increase in cytoskeletal actin and the polyphosphoinositide turnover, its addition inhibits completely the stimulated increase in Ca-influx produced by the same stimulus. The results presented here suggest that a rise in the intracellular concentration of free calcium is neither necessary nor sufficient for the stimulated increase in cytoskeletal-associated actin. A possible relationship between the lipid remodeling stimulated by chemoattractants and the increased cytoskeletal actin is discussed.
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Effects of chemotactic factors and other agents on the amounts of actin and a 65,000-mol-wt protein associated with the cytoskeleton of rabbit and human neutrophils. J Cell Biol 1985; 101:182-8. [PMID: 2989297 PMCID: PMC2113618 DOI: 10.1083/jcb.101.1.182] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Stimulation of rabbit neutrophils by the chemotactic factors fMet-Leu-Phe and leukotriene B4, by platelet activating factor, or by arachidonic acid produces a rapid and dose-dependent increase in the amounts of actin and of a 65,000-mol-wt protein associated with the cytoskeleton. Phorbol 12-myristate, 13-acetate, the calcium ionophore A23187 in the presence or absence of EGTA, and the fluorescent calcium chelator quin-2 also cause an increase in cytoskeletal actin. The stimulated increases in the cytoskeletal actin are not dependent on a rise in the intracellular concentration of free calcium and are not mediated by an increase in the intracellular pH or activation of protein kinase C. The increases in the cytoskeletal actin produced by fMet-Leu-Phe and leukotriene B4, but not by phorbol 12-myristate, 13-acetate, are inhibited by high osmolarity. The effect of hyperosmolarity requires a decrease in cell volume, is not mediated by an increase in basal intracellular concentration of free calcium, and is not prevented by pretreating the cells with amiloride. Preincubation of the cells with hyperosmotic solution also inhibits degranulation produced by all the stimuli tested. The inhibitory action of high osmolarity on the fMet-Leu-Phe and leukotriene B4 induced stimulation of cytoskeletal actin is discussed in terms of the possibility that the addition of high osmolarity, either directly or through activation of protein kinase C, causes receptor uncoupling.
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Abstract
Pertussis toxin treatment of rabbit peritoneal neutrophils causes a concentration-dependent inhibition of granule enzyme secretion induced by formylmethionyl-leucyl-phenylalanine, C5a, and leukotriene B4. It also inhibits chemotaxis induced by formylmethionyl-leucyl-phenylalanine. The same toxin treatment, however, has no effect on granule enzyme secretion induced by the calcium ionophore A23187 or phorbol 12-myristate 13-acetate. Moreover, pertussis toxin treatment does not affect either the number or affinity of the formylpeptide receptors on the neutrophil nor does it have any effect on the unstimulated levels of cyclic AMP (cAMP) or the transient rise in cAMP induced by chemotactic factor stimulation in these cells. We hypothesize that pertussis toxin, as in other cells, interacts with a GTP binding regulatory protein identical with or analogous to either Ni or transducin which mediates the receptor-induced inhibition or activation of a target protein or proteins required in neutrophil activation. The nature of the target protein is unknown, but it is not the catalytic unit of adenylate cyclase. The target protein acts after binding of chemotactic factor to its receptor in the sequence that leads to the receptor-induced rise in intracellular Ca2+. It does not affect the responses elicited by the direct introduction of calcium into the cells or the activity of protein kinase C.
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Pertussis but not cholera toxin inhibits the stimulated increase in actin association with the cytoskeleton in rabbit neutrophils: role of the "G proteins" in stimulus-response coupling. Biochem Biophys Res Commun 1985; 126:1174-81. [PMID: 2983701 DOI: 10.1016/0006-291x(85)90309-2] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Treatment of rabbit neutrophils with pertussis toxin, but not cholera toxin, inhibits the increases produced by formylmethionyl-leucyl-phenylalanine, leukotriene B4 and the calcium ionophore A23187 in the amounts of actin associated with the cytoskeletons. The increase in the cytoskeletal actin produced by phorbol 12-myristate, 13-acetate on the other hand is not affected by pertussis toxin. Incubation of the neutrophils with cholera toxin, unlike pertussis toxin, did not inhibit the fMet-Leu-Phe induced rise in the intracellular concentration of free calcium, and caused only a shift to the right of the dose-response curve of N-acetyl-beta-glucosaminidase release. This shift was more marked in the presence of 1-methyl-3-isobutylxanthine. In addition, the stimulated breakdown of phosphatidylinositol 4,5 bis-phosphate was inhibited by pertussis toxin. These results suggest that pertussis toxin acts at an early step in the signal transduction and does not affect the sequence of reactions initiated by the activation of the protein kinase C. Furthermore, the guanine nucleotide regulatory protein Gi, but not Gs, is closely involved in signal transduction in these cells.
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Leukotriene B4 mobilizes calcium without the breakdown of polyphosphoinositides and the production of phosphatidic acid in rabbit neutrophils. Proc Natl Acad Sci U S A 1984; 81:5966-9. [PMID: 6091126 PMCID: PMC391839 DOI: 10.1073/pnas.81.19.5966] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The addition of fMet-Leu-Phe, leukotriene B4, or arachidonic acid to rabbit neutrophils causes a rise in the level of intracellular free calcium as measured by the fluorescent dye quin-2. The calcium response is rapid and dose-dependent with an ED50 of 0.12 +/- 0.05 nM for leukotriene B4, 0.20 +/- 0.02 nM for fMet-Leu-Phe, and 320 +/- 30 nM for arachidonic acid. However, unlike fMet-Leu-Phe, leukotriene B4 at concentrations up to 70 nM does not cause a significant breakdown of any of the phosphoinositides or the generation of phosphatidic acid, arachidonic acid, or 1,2-diacylglycerol. The addition of arachidonic acid causes little (less than 20%) production of phosphatidic acid. Furthermore, the dose-response curve of the generation of phosphatidic acid by fMet-Leu-Phe is shifted to the right when compared with that for calcium mobilization. The results reported here indicate that, although similar in many respects, there are important qualitative differences between the mechanisms of action of these two chemotactic factors. They also show that calcium mobilization by leukotriene B4 is not mediated by the breakdown of any of the phosphoinositides, and calcium mobilization by leukotriene B4, arachidonic acid, and possibly fMet-Leu-Phe is not mediated by the generation of phosphatidic acid.
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Chemotactic factor causes rapid decreases in phosphatidylinositol,4,5-bisphosphate and phosphatidylinositol 4-monophosphate in rabbit neutrophils. Biochem Biophys Res Commun 1983; 112:957-64. [PMID: 6303343 DOI: 10.1016/0006-291x(83)91711-4] [Citation(s) in RCA: 170] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Stimulation of rabbit neutrophils prelabeled with 32P by the synthetic chemotactic peptide f-Met-Leu-Phe induces a rapid decrease in the radioactivity in both phosphatidylinositol, 4,5 bis phosphate and phosphatidylinositol 4-monophosphate. The mean +/- standard error of the mean values of the maximum decrease in phosphatidylinositol, 4,5 bis phosphate occurred at 10 seconds following stimulation and is equal to 19 +/- 3% of the control value. The corresponding value for phosphatidylinositol 4-monophosphate occurred at 60 seconds following stimulation and is equal to 37 +/- 7% of the control value. On the other hand, the radioactivity in phosphatidic acid and lysophospholipids increased continuously with time following stimulation. The relationship of these changes to calcium release and neutrophil activation is discussed.
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