RESUMO
BACKGROUND: Prior studies suggested that antidepressant use is associated with an increased risk of dementia compared to no use, which is subject to confounding by indication. We aimed to compare the dementia risk among older adults with depression receiving first-line antidepressants (i.e., SSRI/SNRI) versus psychotherapy, which is also considered the first-line therapy for depression. METHODS: This retrospective cohort study was conducted using the US Medical Expenditure Panel Survey from 2010 to 2019. We included adults aged ≥ 50 years diagnosed with depression who initiated SSRI/SNRI or psychotherapy. We excluded patients with a dementia diagnosis before the first record of SSRI/SNRI use or psychotherapy. The exposure was the patient's receipt of SSRI/SNRI (identified from self-report questionnaires) or psychotherapy (identified from the Outpatient Visits or Office-Based Medical Provider Visits files). The outcome was a new diagnosis of dementia within 2 years (i.e., survey panel period) identified using ICD-9/ICD-10 codes from the Medical Conditions file. Using a multivariable logistic regression model, we reported adjusted odds ratios (aORs) with 95% confidence intervals (CIs). We also conducted subgroup analyses by patient sex, age group, race/ethnicity, severity of depression, combined use of other non-SSRI/SNRI antidepressants, and presence of underlying cognitive impairment. RESULTS: Among 2,710 eligible patients (mean age = 61 ± 8, female = 69%, White = 84%), 89% used SSRIs/SNRIs, and 11% received psychotherapy. The SSRI/SNRI users had a higher crude incidence of dementia than the psychotherapy group (16.4% vs. 11.8%), with an aOR of 1.36 (95% CI = 1.06-1.74). Subgroup analyses yielded similar findings as the main analyses, except no significant association for patients who were aged < 65 years (1.23, 95% CI = 0.93-1.62), male (1.34, 95% CI = 0.95-1.90), Black (0.76, 95% CI = 0.48-1.19), had a higher PHQ-2 (1.39, 95% CI = 0.90-2.15), and had underlying cognitive impairment (1.06, 95% CI = 0.80-1.42). CONCLUSIONS: Our findings suggested that older adults with depression receiving SSRIs/SNRIs were associated with an increased dementia risk compared to those receiving psychotherapy.
Assuntos
Demência , Inibidores da Recaptação de Serotonina e Norepinefrina , Humanos , Masculino , Feminino , Idoso , Inibidores Seletivos de Recaptação de Serotonina/efeitos adversos , Estudos Retrospectivos , Antidepressivos/efeitos adversos , Demência/diagnóstico , Demência/epidemiologia , Demência/terapiaRESUMO
Micron-scale structure biphasic calcium phosphate (BCP) materials have demonstrated promising clinical outcomes in the field of bone tissue repair. However, research on biphasic calcium phosphate materials at the nanoscale level remains limited. In this study, we synthesize granular-shaped biphasic calcium phosphate nanomaterials with multiple desirable characteristics, including negatively charged surfaces, non-cytotoxicity, and the capability to penetrate cells, using a nanogrinding dispersion process with a polymeric carboxylic acid as the dispersant. Our results reveal that treating human osteoblasts with 0.5 µg/mL biphasic calcium phosphate nanomaterials results in a marked increase in alkaline phosphatase (ALP) activity and the upregulation of osteogenesis-related genes. Furthermore, these biphasic calcium phosphate nanomaterials exhibit immunomodulatory properties. Treatment of THP-1-derived macrophages with BCP nanomaterials decreases the expression of various inflammatory genes. Biphasic calcium phosphate nanomaterials also mitigate the elevated inflammatory gene expression and protein production triggered by lipopolysaccharide (LPS) exposure in THP-1-derived macrophages. Notably, we observe that biphasic calcium phosphate nanomaterials have the capacity to reverse the detrimental effects of LPS-stimulated macrophage-conditioned medium on osteoblastic activity and mineralization. These findings underscore the potential utility of biphasic calcium phosphate nanomaterials in clinical settings for the repair and regeneration of bone tissue. In conclusion, this study highlights the material properties and positive effects of biphasic calcium phosphate nanomaterials on osteogenesis and immune regulation, opening a promising avenue for further research on inflammatory osteolysis in patients undergoing clinical surgery.
RESUMO
Background: Prior studies suggested that antidepressant use is associated with an increased risk of dementia compared to no use, which is subject to confounding by indication. We aimed to compare the dementia risk among older adults with depression receiving first-line antidepressants (i.e., SSRI/SNRI) versus psychotherapy, which is also considered the first-line therapy for depression. Methods: This retrospective cohort study was conducted using the US Medical Expenditure Panel Survey from 2010 to 2019. We included adults aged ≥50 years diagnosed with depression who initiated SSRI/SNRI or psychotherapy. We excluded patients with a dementia diagnosis before the first record of SSRI/SNRI use or psychotherapy. The exposure was the patient's receipt of SSRI/SNRI (identified from self-report questionnaires) or psychotherapy (identified from the Outpatient Visits or Office-Based Medical Provider Visits files). The outcome was a new diagnosis of dementia within 2 years (i.e., survey panel period) identified using ICD-9/ICD-10 codes from the Medical Conditions file. Using a multivariable logistic regression model, we reported adjusted odds ratios (aORs) with 95% confidence intervals (CIs). We also conducted subgroup analyses by patient sex, age group, race, severity of depression, combined use of other non-SSRI/SNRI antidepressants, and presence of underlying cognitive impairment. Results: Among 2,710 eligible patients (mean age= 61±8, female=69%, white=84%), 89% used SSRIs/SNRIs, and 11% received psychotherapy. The SSRI/SNRI users had a higher crude incidence of dementia than the psychotherapy group (16.1% vs. 12.7%), with an aOR of 1.39 (95% CI=1.21-1.59). Subgroup analyses yielded similar findings as the main analyses, except no significant association for patients who were black (0.75, 95% CI=0.55-1.02), had a higher PHQ-2 (1.08, 95% CI=0.82-1.41), had concomitant non-SSRI/SNRI antidepressants (0.75, 95% CI=0.34-1.66), and had underlying cognitive impairment (0.84, 95% CI=0.66-1.05). Conclusions: Our findings suggested that older adults with depression receiving SSRIs/SNRIs were associated with an increased dementia risk compared to those receiving psychotherapy.
RESUMO
PURPOSE: Hepatitis C virus (HCV) infection has been associated with increased risk of cardiovascular disease (CVD). It is unclear whether HCV treatment affects risk of CVD among patients infected with HCV. We assessed the incidence and risk of CVD among insured patients with HCV infection and evaluated if HCV treatment was associated with reduced CVD risk. METHODS: This retrospective cohort study used MarketScan Commercial and Medicare Supplement databases. Patients newly diagnosed with HCV (vs. patients without HCV) between January 2008 and August 2015 were categorized by treatment (none, insufficient, or minimum effective) based on receipt and duration of anti-HCV treatments. After propensity score matching, time-dependent Cox proportional hazards models were used to compare CVD risk between patients with HCV versus without and between patients with HCV by treatment type and duration. RESULTS: HCV was associated with 13% increased risk of developing CVD overall (adjusted hazard ratio [aHR] 95% CI 1.26-1.35) and with 13% (aHR 1.07-1,18), 9% (aHR 1.03-1.15), and 32% (aHR 1.24-1.40) significantly increased risks of developing coronary artery disease, cerebrovascular disease, and peripheral vascular disease, respectively. Among patients with HCV, compared with no treatment, receipt of minimum effective treatment was associated with 24% decreased risk of CVD, and receipt of insufficient treatment was associated with 14% decreased risk of CVD. CONCLUSIONS: Individuals chronically infected with HCV had a higher incidence of CVD. Among patients with HCV, receipt of antiviral treatment for HCV was associated with decreased risk of CVD.
Assuntos
Doenças Cardiovasculares , Hepatite C Crônica , Hepatite C , Humanos , Estados Unidos/epidemiologia , Idoso , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , Hepacivirus , Estudos Retrospectivos , Medicare , Hepatite C/complicações , Hepatite C/tratamento farmacológico , Hepatite C/epidemiologia , Antivirais/uso terapêutico , Hepatite C Crônica/tratamento farmacológicoRESUMO
Purpose: Medication reconciliation (MedRec) is a process to ensure complete and accurate communication of patient medication information throughout care transitions to prevent medication errors. Hospitals in Taiwan have stride to implement a universal protocol for MedRec. To establish a feasible protocol indigenously, the World Health Organization (WHO) protocol was incorporated with the Taiwan National Health Insurance (NHI) PharmaCloud patient medication profile. The efficiency and error detection capability of this modified protocol was evaluated in two hospitals. Methods: A prospective, non-randomized, unblinded, multicenter cohort study was conducted. Subjects were recruited among patients admitted for colorectal or orthopedic surgery with at least 4 or more chronic drugs. To obtain the best possible medication history (BPMH), the control group was conducted according to the WHO protocol, and the experimental group used the modified WHO protocol with the medication data from the PharmaCloud system. The time spent on the two protocols was recorded. Admission and discharge orders were reconciled against the BPMH to identify any discrepancies. Discrepancies were evaluated by appropriateness, prescribing intentions, and types of inappropriateness. The levels of potential harm were classified for inappropriate discrepancies. Results: The mean time to obtain BPMH in the control group was 34.3±10.8 minutes and in the experimental group 27.5±11.5 minutes (P = 0.01). The experimental group had more subjects with discrepancies (87.9%) than the control (58.3%) (p < 0.001). The discrepancies in both admission and discharge orders for the experimental group (84.5 and 67.2%) were higher than those of the control (47.9 and 37.5%). Many inappropriate discrepancies were classified as the potential harm of level 2 (77.8%). Conclusion: Through the establishment of BPMH with the medication data from the Taiwan NHI PharmaCloud, MedRec could be achieved with greater efficiency and error detection capability in both the admission and discharge order validation processes.
RESUMO
INTRODUCTION: The objective of this study was to estimate the economic impact of providing universal hepatitis C virus testing in commercially insured middle-aged persons who inject drugs in the U.S. METHODS: This study developed a dynamic 10-year economic model to project the clinical and economic outcomes associated with hepatitis C virus testing among middle-aged adult persons who inject drugs, from a payer's perspective. Costs related to hepatitis C virus testing, direct-acting antiviral, and liver-related outcomes between the (1) current hepatitis C virus testing rate (i.e., 8%) and (2) universal hepatitis C virus testing rate (i.e., 100%) were compared. Among patients testing positive, 21% of those without cirrhosis and 48% of those with cirrhosis were assumed to initiate direct-acting antivirals. Sensitivity analyses were performed to identify variables (e.g., direct-acting antiviral drug costs, hepatitis C virus testing costs, direct-acting antiviral treatment rate) influencing this study's conclusion. RESULTS: The model predicts that during the 10-year period, universal hepatitis C virus testing will cost an additional $242 per person who injects drugs to the payers' healthcare budgets compared with the current scenario. Sensitivity analyses showed values ranging from $1,656 additional costs to $1,085 cost savings across all varied parameters and scenarios. A total of 80% of the current direct-acting antiviral costs indicated that cost savings will be $383 per person who injects drugs. CONCLUSIONS: Universal hepatitis C virus testing among persons who inject drugs would not achieve cost savings within 10 years, with the cost of direct-acting antivirals contributing the most to the spending. To promote universal hepatitis C virus testing among persons who inject drugs, decreasing direct-acting antiviral costs and sustainable funding streams for hepatitis C virus testing should be considered.
Assuntos
Usuários de Drogas , Hepatite C Crônica , Hepatite C , Abuso de Substâncias por Via Intravenosa , Pessoa de Meia-Idade , Adulto , Humanos , Hepacivirus , Antivirais/uso terapêutico , Análise Custo-Benefício , Abuso de Substâncias por Via Intravenosa/complicações , Hepatite C/diagnóstico , Hepatite C/tratamento farmacológicoRESUMO
UVA/riboflavin corneal cross-linking (CXL) is a common used approach to treat progressive keratoconus. This study aims to investigate the alteration of corneal stiffness following CXL by mimicking the inflation of the eye under the in vivo loading conditions. Seven paired porcine eye globes were involved in the inflation test to examine the corneal behaviour. Cornea-only model was constructed using the finite element method, without considering the deformation contribution from sclera and limbus. Inverse analysis was conducted to calibrate the non-linear material behaviours in order to reproduce the inflation test. The corneal stress and strain values were then extracted from the finite element models and tangent modulus was calculated under stress level at 0.03 MPa. UVA/riboflavin cross-linked corneas displayed a significant increase in the material stiffness. At the IOP of 27.25 mmHg, the average displacements of corneal apex were 307 ± 65 µm and 437 ± 63 µm (p = 0.02) in CXL and PBS corneas, respectively. Comparisons performed on tangent modulus ratios at a stress of 0.03 MPa, the tangent modulus measured in the corneas treated with the CXL was 2.48 ± 0.69, with a 43±24% increase comparing to its PBS control. The data supported that corneal material properties can be well-described using this inflation methods following CXL. The inflation test is valuable for investigating the mechanical response of the intact human cornea within physiological IOP ranges, providing benchmarks against which the numerical developments can be translated to clinic.
Assuntos
Córnea/efeitos dos fármacos , Ceratocone/terapia , Refração Ocular/efeitos dos fármacos , Riboflavina/farmacologia , Algoritmos , Animais , Fenômenos Biomecânicos , Córnea/fisiopatologia , Reagentes de Ligações Cruzadas/farmacologia , Modelos Animais de Doenças , Humanos , Pressão Intraocular/efeitos dos fármacos , Ceratocone/fisiopatologia , Refração Ocular/fisiologia , Suínos , Raios Ultravioleta , Terapia Ultravioleta/métodosRESUMO
PURPOSE: To determine the relationship between mechanical behavior in cross-linked corneas and changes in the corneal ultrastructure after corneal cross-linking (CXL). METHODS: Porcine corneas were treated following the "Dresden" protocol, the current gold standard for clinical treatment, consisting of dropwise application of 0.1% riboflavin in 20% dextran followed by 30 minutes of ultraviolet-A (UVA) irradiation. The effect of CXL was assessed using uniaxial tensile testing, transmission electron microscopy, and Fourier transform infrared spectroscopy, with results compared against corneas treated with each of the treatment solution components individually. RESULTS: UVA/riboflavin cross-linked corneas displayed 28% ± 17% increase in the material tangent modulus compared with dextran treatment alone, and altered collagen architecture within the first 300 µm of stromal depth consisting of 5% increase in the thickness of collagen fibrils, no significant changes to interfibrillar spacing, and an 8% to 12% decrease in number of fibrils per unit area. Fourier transform infrared spectroscopy confirmed formation of interfibrillar bonds (P = .012) induced by UVA-mediated CXL. CONCLUSIONS: The data support a model wherein collagen fibril diameter and structural density are fundamental parameters in defining tissue stiffening following UVA/riboflavin CXL and provide benchmarks against which modifications to the Dresden CXL protocol can be evaluated. [J Refract Surg. 2018;34(4):264-272.].
Assuntos
Colágeno/metabolismo , Córnea/ultraestrutura , Reagentes de Ligações Cruzadas , Ceratocone/tratamento farmacológico , Fármacos Fotossensibilizantes/uso terapêutico , Riboflavina/uso terapêutico , Animais , Fenômenos Biomecânicos , Córnea/fisiopatologia , Substância Própria/metabolismo , Ceratocone/metabolismo , Ceratocone/fisiopatologia , Microscopia Eletrônica de Transmissão , Espectroscopia de Infravermelho com Transformada de Fourier , Suínos , Raios UltravioletaRESUMO
Poly(N-(4-aminobutyl)-acrylamide) (P4Am) and poly-d-lysine (PDL) possess the same butylamine side chain. The main difference is the peptide structure, which is in the main chain of PDL but in the side chain of P4Am. PDL has been extensively used in the preparation of neuronal cultures. We assumed neurons are sensitive enough to distinguish such structure difference so these two cationic polymers were compared at serial coating concentrations for culturing cerebellar granule neurons from 7-day-old Wistar rats in this study. Cellular viability and morphology assay showed no obvious difference for neurons cultured at high coating concentrations (>0.31 µg/mL) of these two polymers. In contrast, the difference in the peptide structure between P4Am and PDL could be distinguished by neurons at low coating concentrations (< 0.16 µg/mL). P4Am at low coating concentration could keep aggregates with three or four thick processes to support a more complete neural network with higher cellular viability than PDL. This suggests the interaction between neurons and the specific peptide structure of P4Am at low coating concentration was able to improve survival and differentiation of cultured cerebellar granule neurons. Although neural cells exhibited different morphologies and activities on high and low P4Am coating concentrations, immunofluorescence imaging confirmed most of cultured cells were functionally mature neurons, stained by neurofilament, synapsin I, and GAP43. The information should be useful for designing new biomaterials for regeneration of damaged circuits following disease or trauma. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1194-1201, 2018.
Assuntos
Acrilamidas/farmacologia , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cerebelo/citologia , Neurônios/efeitos dos fármacos , Polilisina/farmacologia , Animais , Células Cultivadas , Cerebelo/metabolismo , Imuno-Histoquímica , Rede Nervosa/citologia , Rede Nervosa/efeitos dos fármacos , Regeneração Nervosa/efeitos dos fármacos , Proteínas do Tecido Nervoso/biossíntese , Neurônios/metabolismo , Neurônios/ultraestrutura , Ratos , Ratos Wistar , Relação Estrutura-AtividadeRESUMO
PURPOSE: Heparan sulfate (HS) is a highly modified glycosaminoglycan (GAG) bound to a core protein to form heparan sulfate proteoglycans (HSPGs) that are vital in many cellular processes ranging from development to adult physiology, as well as in disease, through interactions with various protein ligands. This study aimed to elucidate the role of HS in corneal epithelial homeostasis and wound healing. METHODS: An inducible quadruple transgenic mouse model was generated to excise Ext1 and Ndst1, which encode the critical HS chain elongation enzyme and N-deacetylase/N-sulfotransferase, respectively, in keratin 14-positive cells upon doxycycline induction. RESULTS: EXT(Δ/ΔCEpi) mice (deletion of Ext1 in corneal epithelium) induced at P20 presented progressive thinning of the corneal epithelium with a significant loss in the number of epithelial layers by P55. EXT(Δ/ΔCEpi) mice presented tight junction disruption, loss of cell-basement membrane adhesion complexes, and impaired wound healing. Interestingly, EXT(Δ/ΔCEpi) and NDST(Δ/ΔCEpi) mice presented an increase in cell proliferation, which was assayed by both Ki67 staining and 5-ethynyl-2'-deoxyuridine (EdU) incorporation. Moreover, EXT(Δ/ΔCEpi) mice presented compromised epithelial stratification 7 days after a debridement wound. The conditional knockout of HS from keratocytes using the keratocan promoter led to no corneal abnormalities or any disruption in wound healing. CONCLUSIONS: Corneal epithelial cells require HS for maintaining corneal homeostasis, and the loss of epithelial HS leads to both impaired wound healing and impaired corneal stratification.
Assuntos
Doenças da Córnea/metabolismo , Epitélio Corneano/metabolismo , Heparitina Sulfato/metabolismo , Homeostase/fisiologia , Cicatrização/fisiologia , Animais , Imunofluorescência , Imuno-Histoquímica , Camundongos , Camundongos Knockout , Microscopia EletrônicaRESUMO
In this study, we compared the detachment ratio of HaCaT and Hs68 cells from pH-responsive chitosan surface by raising medium pH from 7.20 to 7.65 for 60 min. The detachment ratio of elongated Hs68 cells was over 75%, but that of round-shaped HaCaT cells was less than 50%, even extending the incubation time to 6 h or enhancing the cytoskeletal contractile force with the Rho activator CN01. However, the addition of 2 mm of EDTA into the medium at pH 7.65 could effectively detach HaCaT cells (detachment ratio > 90%), indicating that the calcium ion played an important role in the detachment process. Therefore, the family of Ca(+2)-dependent integrin receptors was examined by RT-PCR, real-time PCR and immunocytochemistry. It was found the expression of integrin ß4 (ITGb4) was HaCaT cell-specific and the mRNA level of ITGb4 in undetached HaCaT cells was significantly higher than that in detached ones. By modulating ITGb4 activity with specific functional blocking antibody ASC-8, the detachment ratio of HaCaT cells could be increased to be greater than 85%. Conversely, the addition of the ligand of ITGb4 laminin into the culture system decreased the medium pH-induced detachment ratio for HaCaT cells, but not for Hs68 cells. Further addition of ASC-8 could rescue the effect of laminin on preventing the detachment of HaCaT cells from pH-sensitive chitosan surface. Therefore, this study demonstrated the interaction of ITGb4 and laminin played an important role in controlling the detachment of HaCaT cells on pH-responsive chitosan.
Assuntos
Quitosana/química , Queratinócitos/citologia , Linhagem Celular , Meios de Cultura/química , Humanos , Concentração de Íons de Hidrogênio , Imuno-Histoquímica , Integrina beta4/metabolismo , Laminina/química , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Lumican (Lum), a small leucine-rich proteoglycan (SLRP) family member, has multiple matricellular functions both as an extracellular matrix component and as a matrikine regulating cell proliferation, gene expression and wound healing. To date, no cell surface receptor has been identified to mediate the matrikine functions of Lum. This study aimed to identify a perspective receptor that mediates Lum effects on promoting wound healing. Transforming growth factor-ß receptor 1 (ALK5) was identified as a potential Lum-interacting protein through in silico molecular docking and molecular dynamics. This finding was verified by biochemical pull-down assays. Moreover, the Lum function on wound healing was abrogated by an ALK5-specific chemical inhibitor as well as by ALK5 shRNAi. Finally, we demonstrated that eukaryote-specific post-translational modifications are not required for the wound healing activity of Lum, as recombinant GST-Lum fusion proteins purified from E. coli and a chemically synthesized LumC13 peptide (the last C-terminal 13 amino acids of Lum) have similar effects on wound healing in vitro and in vivo.
Assuntos
Proteoglicanas de Sulfatos de Condroitina/metabolismo , Sulfato de Queratano/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Adulto , Idoso , Animais , Western Blotting , Linhagem Celular , Células Cultivadas , Proteoglicanas de Sulfatos de Condroitina/genética , Feminino , Imunofluorescência , Humanos , Sulfato de Queratano/genética , Lumicana , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Simulação de Dinâmica Molecular , Proteínas Serina-Treonina Quinases/genética , Proteoglicanas/genética , Proteoglicanas/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta/genética , Cicatrização/genética , Cicatrização/fisiologiaRESUMO
The proximal tubule performs a variety of important renal functions and is the major site for nutrient reabsorption. The purpose of this study is to culture rat renal proximal tubule cells (PTCs) on chitosan without serum to maintain a transcellular pathway to transport water and ions effectively without loss of highly differentiated cell function. The effect of chitosan, which is structurally similar to glycosaminoglycans, in the absence of serum on the primary cultured PTCs was compared that of collagen with or without serum. Two days after seeding, more tubule fragments and higher PTC viability were observed on chitosan than on collagen with or without serum. Proliferation marker Ki-67 immunostaining and phosphorylated extracellular-regulated kinase (ERK) expression results displayed similar proliferation capability of PTCs established on chitosan without serum and collagen with 2% fetal bovine serum after 4 days of incubation. When grown to confluence, PTCs formed a monolayer with well-organized tight junctions and formation of domes on chitosan without serum. Moreover, evaluation of the transepithelial electrical resistance showed that both chitosan and serum were involved in the modification of water and ion transport in confluent cells. By showing the direct suppression of PTC growth and dome formation treated with heparinase, we demonstrated that the interaction between cell surface heparin sulfate proteoglycan and chitosan played an important role in PTC proliferation and differentiation. A successful primary culture of PTCs has now been produced on chitosan in serum-free culture condition, which offers potential applications for chitosan in renal tissue engineering.
Assuntos
Técnicas de Cultura de Células/métodos , Quitosana/farmacologia , Túbulos Renais Proximais/citologia , Túbulos Renais Proximais/efeitos dos fármacos , Fosfatase Alcalina/metabolismo , Animais , Caderinas/metabolismo , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Células Cultivadas , Colágeno/farmacologia , Meios de Cultura Livres de Soro/farmacologia , Impedância Elétrica , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Heparina Liase/farmacologia , Túbulos Renais Proximais/enzimologia , Masculino , Ratos , Ratos Wistar , ATPase Trocadora de Sódio-Potássio/metabolismo , Junções Íntimas/efeitos dos fármacos , Junções Íntimas/metabolismo , Proteína da Zônula de Oclusão-1/metabolismoRESUMO
The purpose of this study is to demonstrate pH-responsive chitosan is able to be used for cell fractionation under precise adjustment of medium pH. Cells were first seeded to attach on chitosan surface at medium pH 7.20 for 24 h. After raising medium pH to 7.65 for 1 h, cells with elongated morphology possessed rapider detachment rate and cells with round shape detached at a lesser rate. Therefore, successful cell separation has been achieved by choosing appropriate cell combination with different detachment rates without additional antibody or enzyme treatment and extensive washing steps. Furthermore, the method also could be applied to specific manipulation of viable cell populations from tissue specimen. Most importantly and interestingly, the efficiency of cell fractionation of our system could be theoretically predicted according to the individual cell detachment rate on pH-responsive chitosan surface, without considering the presence of heterotypic cells.
Assuntos
Materiais Biocompatíveis/química , Adesão Celular/fisiologia , Fracionamento Celular/métodos , Separação Celular/métodos , Quitosana/química , Tamanho Celular , Humanos , Concentração de Íons de Hidrogênio , Teste de MateriaisRESUMO
This paper presents a miniature fluidic probe that is capable of self-adapting its shape to teeth and cooperating with electrical devices to detect dental caries by sensing the variation in electrical- impedance. The fluidic probe, whose liquid tip spontaneously spreads on hydrophilic tooth surface and into underlying caries, is employed to create intimate electrical contact for impedance sensing. A tubular air sleeve shaped by the probe casing is applied around the liquid tip to insulate it from surrounding saliva, and to regulate its spreading. In addition, a friction damper is integrated to stabilize the actuation of fluidic probe. In the prototype demonstration, un-restored, extracted premolar teeth were investigated and the results indicated >20-fold impedance differences between sound and carious teeth, by which caries could be identified in a consistent manner. Furthermore, the fluidic probe has been applied to detect approximal caries, which locates in the contacting surfaces of two adjacent teeth and is difficult to detect by most available schemes. As such, the proposed self-adaptive fluidic probe could readily serve as a diagnostic tool, which is critical to caries prevention and various dental-care applications.