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1.
BMC Womens Health ; 23(1): 155, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-37005669

RESUMO

BACKGROUND: There is a paucity of information regarding the mental health of midwives working in Ontario, Canada. Many studies have investigated midwives' mental health around the world, but little is known about how the model of midwifery care in Ontario contributes to or negatively impacts midwives' mental health. The aim of the study was to gain a deeper understanding of factors that contribute to and negatively impact Ontario midwives' mental health. METHODS: We employed a mixed-methods, sequential, exploratory design, which utilized focus groups and individual interviews, followed by an online survey. All midwives in Ontario who had actively practiced within the previous 15 months were eligible to participate. FINDINGS: We conducted 6 focus groups and 3 individual interviews, with 24 midwives, and 275 midwives subsequently completed the online survey. We identified four broad factors that impacted midwives' mental health: (1) the nature of midwifery work, (2) the remuneration model, (3) the culture of the profession, and (4) external factors. DISCUSSION: Based on our findings and the existing literature, we have five broad recommendations for improving Ontario midwives' mental health: (1) provide a variety of work options for midwives; (2) address the impacts of trauma on midwives; (3) make mental health services tailored for midwives accessible; (4) support healthy midwife-to-midwife relationships; and (5) support improved respect and understanding of midwifery. CONCLUSION: As one of the first comprehensive investigations into midwives' mental health in Ontario, this study highlights factors that contribute negatively to midwives' mental health and offers recommendations for how midwives' mental health can be improved systemically.


Assuntos
Enfermeiros Obstétricos , Estresse Ocupacional , Saúde Mental , Tocologia , Enfermeiros Obstétricos/psicologia , Esgotamento Profissional , Ontário , Serviços de Saúde Mental , Grupos Focais , Pesquisa Qualitativa , Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso
2.
Lasers Surg Med ; 52(1): 84-87, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31736123

RESUMO

BACKGROUND AND OBJECTIVES: Actinic keratoses (AK) are common pre-cancerous lesions, which are associated with ultraviolet light exposure and aging. Wounding therapies such as fractionated laser resurfacing (FLR) have been previously demonstrated to effectively treat facial AK. However, the effectiveness of FLR on other sites commonly afflicted with AK has not been studied in detail. Previously, our group has reported that treatment of aged skin with wounding therapies including dermabrasion and ablative fractionated resurfacing results in the removal of senescent fibroblasts and normalizing the pro-carcinogenic acute ultraviolet B radiation responses associated with aged skin. The current studies were designed to test the effectiveness of FLR of the forearm skin of subjects aged 60 and older to remove AKs. STUDY DESIGN/MATERIALS AND METHODS: Between February 2018 and March 2019, 30 subjects were enrolled in a study, in which they underwent a single FLR treatment of one extremity including the dorsal forearm, wrist, and dorsal hand. The number of AKs was recorded on both extremities at baseline, 3 and 6 months in a blinded fashion. Side effects of the FLR were documented. RESULTS: A single FLR treatment resulted in a 62% reduction in the absolute number of AK in the treated arm at 6 months post-treatment. The laser treatment was well-tolerated without major complications. CONCLUSIONS: These studies demonstrate that FLR using settings, which have demonstrated to remove senescent fibroblasts and normalize the pro-carcinogenic UVB-response of aged skin is a potentially effective and safe field therapy treatment that should be studied for long-term efficacy for use in treating upper extremity AKs. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.


Assuntos
Ceratose Actínica/radioterapia , Terapia com Luz de Baixa Intensidade , Fatores Etários , Idoso , Seguimentos , Antebraço , Humanos , Ceratose Actínica/patologia , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Resultado do Tratamento
3.
Women Birth ; 37(4): 101613, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38615516

RESUMO

PROBLEM: Burnout and the psychological co-morbidities stress, anxiety and depression have a significant impact on healthcare providers, including midwives. These conditions impact the quality of care provided to women, and midwives' ability to remain in the profession. BACKGROUND: There is growing concern regarding the retention of maternity care providers in Canada, particularly midwives. Nationally, 33% of Canadian midwives are seriously considering leaving practice; impacts of the profession on work-life-balance and mental health being commonly cited reasons. Burnout has been shown to contribute to workplace attrition, but little is known concerning burnout among Canadian midwives. AIM: To assess levels of stress, anxiety, depression, and burnout among midwives in Ontario, Canada and potential factors associated with these conditions. METHODS: A cross-sectional survey of Ontario midwives incorporating a series of well-validated tools including the Copenhagen Burnout Inventory and the Depression, Anxiety and Stress Scale. FINDINGS: Between February 5, and April 14, 2021, 275 Ontario midwives completed the survey. More than 50% of respondents reported depression, anxiety, stress, and burnout. Factors associated with poor mental health outcomes included having less than 10-years practice experience, identifying as a midwife with a disability, the inability to work off-call, and having taken a prior mental health leave. DISCUSSION & CONCLUSION: A significant proportion of Ontario midwives are experiencing high levels of stress, anxiety, depression, and burnout, which should be a serious concern for the profession, its leaders, and regulators. Investment in strategies aimed at retaining midwives that address underlying factors leading to attrition should be prioritized.

4.
J Biol Chem ; 287(20): 16132-45, 2012 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-22447928

RESUMO

Gram-negative bacteria release lipopolysaccharide (LPS) into the bloodstream. Here, it engages Toll-like receptor (TLR) 4 expressed in human lung microvascular endothelia (HMVEC-Ls) to open the paracellular pathway through Src family kinase (SFK) activation. The signaling molecules that couple TLR4 to the SFK-driven barrier disruption are unknown. In HMVEC-Ls, siRNA-induced silencing of TIRAP/Mal and overexpression of dominant-negative TIRAP/Mal each blocked LPS-induced SFK activation and increases in transendothelial [(14)C]albumin flux, implicating the MyD88-dependent pathway. LPS increased TRAF6 autoubiquitination and binding to IRAK1. Silencing of TRAF6, TRAF6-dominant-negative overexpression, or preincubation of HMVEC-Ls with a cell-permeable TRAF6 decoy peptide decreased both LPS-induced SFK activation and barrier disruption. LPS increased binding of both c-Src and Fyn to GST-TRAF6 but not to a GST-TRAF6 mutant in which the three prolines in the putative Src homology 3 domain-binding motif (amino acids 461-469) were substituted with alanines. A cell-permeable decoy peptide corresponding to the same proline-rich motif reduced SFK binding to WT GST-TRAF6 compared with the Pro → Ala-substituted peptide. Finally, LPS increased binding of activated Tyr(P)(416)-SFK to GST-TRAF6, and preincubation of HMVEC-Ls with SFK-selective tyrosine kinase inhibitors, PP2 and SU6656, diminished TRAF6 binding to c-Src and Fyn. During the TRAF6-SFK association, TRAF6 catalyzed Lys(63)-linked ubiquitination of c-Src and Fyn, whereas SFK activation increased tyrosine phosphorylation of TRAF6. The TRAF6 decoy peptide blocked both LPS-induced SFK ubiquitination and TRAF6 phosphorylation. Together, these data indicate that the proline-rich Src homology 3 domain-binding motif in TRAF6 interacts directly with activated SFKs to couple LPS engagement of TLR4 to SFK activation and loss of barrier integrity in HMVEC-Ls.


Assuntos
Permeabilidade Capilar/fisiologia , Transdução de Sinais/fisiologia , Fator 6 Associado a Receptor de TNF/metabolismo , Receptor 4 Toll-Like/metabolismo , Quinases da Família src/metabolismo , Motivos de Aminoácidos , Permeabilidade Capilar/efeitos dos fármacos , Células Cultivadas , Células Endoteliais , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/fisiologia , Inativação Gênica , Humanos , Quinases Associadas a Receptores de Interleucina-1/genética , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Lipopolissacarídeos/farmacologia , Pulmão , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Peptídeos/farmacologia , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/genética , Proteínas Proto-Oncogênicas c-fyn/genética , Proteínas Proto-Oncogênicas c-fyn/metabolismo , Receptores de Interleucina-1/genética , Receptores de Interleucina-1/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator 6 Associado a Receptor de TNF/agonistas , Fator 6 Associado a Receptor de TNF/genética , Receptor 4 Toll-Like/genética , Ubiquitinação/efeitos dos fármacos , Ubiquitinação/genética , Quinases da Família src/genética
5.
Heliyon ; 9(11): e21619, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37942147

RESUMO

Idiopathic granulomatous mastitis is a rare breast condition of unclear etiology. Its course is often rapidly progressive, slow to resolve, and can have a high rate of recurrence. Clinical presentation can mimic breast abscess, infectious mastitis, and carcinoma of the breast, generating a diagnostic challenge. Histopathological analysis is required to make the diagnosis after common conditions are excluded. There is no standard treatment, however surgical excision, steroid treatment, and observation are commonly reported approaches. Here, we describe a complex case of a multiparous patient presenting with idiopathic granulomatous mastitis at 32 weeks gestation. In this review, we highlight the importance of collaboration amongst a multidisciplinary team for effective diagnosis and treatment. We discuss the use of oral corticosteroids in the antenatal period and illustrate the patient support required to both facilitate successful breastfeeding in the postpartum period and promote recovery.

6.
Sci Rep ; 13(1): 20876, 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-38012223

RESUMO

In this work material synergy with high stiffness carbon fiber with ductile high strength polypropylene fiber (Innegra S), (referred to as Innegra, herein) have been evaluated in a range of laminate designs. Both woven and discontinuous carbon fiber have been considered. The discontinuous fibers are based on three-dimensional deposition (3DEP) (referred to as 3DEP, herein) carbon fiber preform process. Eleven (11) variants of Innegra-carbon fiber hybrid laminates were investigated for tensile, flexure, compression, in-plane shear and low velocity impact response. The effect of position of Innegra within the laminate was studied and found to influence strength and stiffness properties. In terms of overall trends, Innegra provides upward of 18% improvement in strain (ductility) to the composite and eliminates brittle fracture of carbon fiber. The moduli trends follow the proportionality of Innegra fiber to carbon fiber plies. However, the strength is controlled by the interface between Innegra and carbon fiber. The primary failure mode in tension and compression is via onset of debonding between Innegra and carbon fiber. The 3DEP carbon fiber constituents provided highest values of in-plane shear indicating that three-dimensional (3D) network of carbon fiber provides higher shear resistance. The Innegra intensive variants exhibited superior energy absorption under low velocity impact, at energy levels 15-60 J. This work provides insight for designers to incorporate Innegra and carbon fiber hybrids in composite structures.

7.
J Invest Dermatol ; 143(7): 1279-1288.e9, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36708950

RESUMO

Although effective in treating actinic damage, topical photodynamic therapy (PDT) has been shown to be immunosuppressive through unknown mechanisms, which could potentially limit its effectiveness. Multiple types of environmental stressors, including PDT, can produce the immunosuppressive lipid mediator platelet-activating factor (PAF). Because PAF can produce subcellular microvesicle particles (MVPs), these studies tested whether PDT can generate PAF and MVP release and whether these are involved in PDT-induced immunosuppression. Previously, topical PDT using blue light and 5-aminolevulinic acid was found to be a potent stimulus for PAF production in mice and human skin explants and human patients, and we show that experimental PDT also generates high levels of MVP. PDT-generated MVPs were independent of the PAF receptor but were dependent on the MVP-generating enzyme acid sphingomyelinase. Patients undergoing topical PDT treatment to at least 10% of body surface area showed local and systemic immunosuppression as measured by inhibition of delayed-type hypersensitivity reactions. Finally, using a murine model of contact hypersensitivity, PDT immunosuppression was blocked by genetic and pharmacologic inhibition of acid sphingomyelinase and genetic inhibition of PAF receptor signaling. These studies describe a mechanism involving MVP through which PDT exerts immunomodulatory effects, providing a potential target to improve its effectiveness.


Assuntos
Fotoquimioterapia , Esfingomielina Fosfodiesterase , Humanos , Camundongos , Animais , Esfingomielina Fosfodiesterase/metabolismo , Esfingomielina Fosfodiesterase/farmacologia , Pele/metabolismo , Ácido Aminolevulínico , Tolerância Imunológica , Imunossupressores/farmacologia , Fármacos Fotossensibilizantes
8.
Front Med (Lausanne) ; 9: 1022766, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36405612

RESUMO

Background: Lyme disease (LD) is a complex tick-borne pathology caused by Borrelia burgdorferi sensu lato bacteria. Currently, there are limited data regarding the health outcomes of people infected during pregnancy, the potential for perinatal transmission to their fetus, and the long-term effects on these children. Therefore, the primary objective of this survey study was to investigate the impact of LD in pregnancy on both the parent and their offspring. Methods: A seven-section survey was developed and administered in REDCap. Although recruitment was primarily through LD-focused organizations, participation was open to anyone over the age of 18 who had been pregnant. Participant health/symptoms were compared across those with "Diagnosed LD," "Suspected LD," or "No LD" at any time in their lives. The timing of LD events in the participants' histories (tick bite, diagnosis, treatment start, etc.) were then utilized to classify the participants' pregnancies into one of five groups: "Probable Treated LD," "Probable Untreated LD," "Possible Untreated LD," "No Evidence of LD," and "Unclear." Results: A total of 691 eligible people participated in the survey, of whom 65% had Diagnosed LD, 6% had Suspected LD, and 29% had No LD ever. Both the Diagnosed LD and Suspected LD groups indicated a high symptom burden (p < 0.01). Unfortunately, direct testing of fetal/newborn tissues for Borrelia burgdorferi only occurred following 3% of pregnancies at risk of transmission; positive/equivocal results were obtained in 14% of these cases. Pregnancies with No Evidence of LD experienced the fewest complications (p < 0.01) and were most likely to result in a live birth (p = 0.01) and limited short- and long-term offspring pathologies (p < 0.01). Within the LD-affected pregnancy groups, obtaining treatment did not decrease complications for the parent themselves but did ameliorate neonatal health status, with reduced rates of rashes, hypotonia, and respiratory distress (all p < 0.01). The impact of parent LD treatment on longer-term child outcomes was less clear. Conclusion: Overall, this pioneering survey represents significant progress toward understanding the effects of LD on pregnancy and child health. A large prospective study of pregnant people with LD, combining consistent diagnostic testing, exhaustive assessment of fetal/newborn samples, and long-term offspring follow-up, is warranted.

9.
J Matern Fetal Neonatal Med ; 34(11): 1814-1821, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31362572

RESUMO

OBJECTIVE: Group B streptococcus (GBS) vaginal/rectal colonization in pregnancy has been associated with early-onset GBS disease (EOGBSD), a leading cause of neonatal morbidity and mortality. In Canada, universal screening for GBS colonization is offered to pregnant people at 35-37 weeks' gestation and those who test positive are offered intrapartum antibiotic prophylaxis (IAP). Universal screening and treatment with IAP have not eradicated all cases of EOGBSD, and IAP has documented side effects. Probiotic supplements have been proposed as a possible way to reduce GBS colonization. MATERIALS AND METHODS: Pregnant midwifery clients >18 years of age and <45 years of age and with a gestational age of <25 weeks at the time of enrolment were randomly assigned to receive two capsules of probiotics (Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14) or placebo orally daily for 12 weeks at 23-25 weeks' gestation. The primary aim was to determine the feasibility of a larger study. The rate of GBS vaginal/rectal colonization at 35-37 weeks' gestation was also assessed in both groups. RESULTS: In total, 139 pregnant midwifery clients were randomized (probiotic group [N = 73] and placebo group [N = 66]). Of these, 113 were included in the final analysis (probiotic group [N = 57] and placebo group [N = 56]). Baseline characteristics between groups were similar with the exception of gestational age (p < .01). The recruitment rate was low at 12%, but the mean compliance rate was 87%. The eligibility/ineligibility criteria were too strict and changes to the study design will be required for the larger proposed study. The rates of vaginal/rectal GBS colonization did not differ significantly between groups (15.8 versus 21.43%; p = .48). No adverse effects were documented in the probiotic group. CONCLUSION: This was the first midwifery-led trial involving a natural health product in the province of Ontario. Although treatment with oral probiotics is feasible, the results were not superior to placebo in reducing the rate of GBS colonization. An adequately powered, randomly controlled trial is required to assess the effectiveness of the two probiotic strains.


Assuntos
Lacticaseibacillus rhamnosus , Limosilactobacillus reuteri , Tocologia , Probióticos , Infecções Estreptocócicas , Método Duplo-Cego , Feminino , Humanos , Lactente , Recém-Nascido , Ontário , Projetos Piloto , Gravidez , Infecções Estreptocócicas/prevenção & controle , Streptococcus agalactiae , Vagina
10.
J Clin Invest ; 131(19)2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34428179

RESUMO

BACKGROUNDThe loss of insulin-like growth factor 1 (IGF-1) expression in senescent dermal fibroblasts during aging is associated with an increased risk of nonmelanoma skin cancer (NMSC). We tested how IGF-1 signaling can influence photocarcinogenesis during chronic UVB exposure to determine if fractionated laser resurfacing (FLR) of aged skin, which upregulates dermal IGF-1 levels, can prevent the occurrence of actinic keratosis (AK) and NMSC.METHODSA human skin/immunodeficient mouse xenografting model was used to test the effects of a small molecule inhibitor of the IGF-1 receptor on chronic UVB radiation. Subsequently, the durability of FLR treatment was tested on a cohort of human participants aged 65 years and older. Finally, 48 individuals aged 60 years and older with considerable actinic damage were enrolled in a prospective randomized clinical trial in which they underwent a single unilateral FLR treatment of one lower arm. Numbers of AKs/NMSCs were recorded on both extremities for up to 36 months in blinded fashion.RESULTSXenografting studies revealed that chronic UVB treatment with a topical IGF-1R inhibitor resulted in a procarcinogenic response. A single FLR treatment was durable in restoring appropriate UVB response in geriatric skin for at least 2 years. FLR resulted in sustained reduction in numbers of AKs and decreased numbers of NMSCs in the treated arm (2 NMSCs) versus the untreated arm (24 NMSCs).CONCLUSIONThe elimination of senescent fibroblasts via FLR reduced the procarcinogenic UVB response of aged skin. Thus, wounding therapies are a potentially effective prophylaxis for managing high-risk populations.TRIAL REGISTRATIONClinicalTrials.gov (NCT03906253).FUNDINGNational Institutes of Health, Veterans Administration.


Assuntos
Ceratose Actínica/prevenção & controle , Terapia a Laser/métodos , Envelhecimento da Pele/efeitos da radiação , Neoplasias Cutâneas/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Animais , Feminino , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Receptor IGF Tipo 1/antagonistas & inibidores , Receptor IGF Tipo 1/fisiologia , Raios Ultravioleta
11.
J Clin Invest ; 131(10)2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-33830943

RESUMO

A complete carcinogen, ultraviolet B (UVB) radiation (290-320 nm), is the major cause of skin cancer. UVB-induced systemic immunosuppression that contributes to photocarcinogenesis is due to the glycerophosphocholine-derived lipid mediator platelet-activating factor (PAF). A major question in photobiology is how UVB radiation, which only absorbs appreciably in the epidermal layers of skin, can generate systemic effects. UVB exposure and PAF receptor (PAFR) activation in keratinocytes induce the release of large numbers of microvesicle particles (MVPs; extracellular vesicles ranging from 100 to 1000 nm in size). MVPs released from skin keratinocytes in vitro in response to UVB (UVB-MVPs) are dependent on the keratinocyte PAFR. Here, we used both pharmacologic and genetic approaches in cells and mice to show that both the PAFR and enzyme acid sphingomyelinase (aSMase) were necessary for UVB-MVP generation. Our discovery that the calcium-sensing receptor is a keratinocyte-selective MVP marker allowed us to determine that UVB-MVPs leaving the keratinocyte can be found systemically in mice and humans following UVB exposure. Moreover, we found that UVB-MVPs contained bioactive contents including PAFR agonists that allowed them to serve as effectors for UVB downstream effects, in particular UVB-mediated systemic immunosuppression.


Assuntos
Micropartículas Derivadas de Células/imunologia , Tolerância Imunológica/efeitos da radiação , Queratinócitos/imunologia , Raios Ultravioleta , Animais , Linhagem Celular , Micropartículas Derivadas de Células/genética , Feminino , Humanos , Camundongos , Camundongos Knockout , Fator de Ativação de Plaquetas/genética , Fator de Ativação de Plaquetas/imunologia , Glicoproteínas da Membrana de Plaquetas/genética , Glicoproteínas da Membrana de Plaquetas/imunologia , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/imunologia , Esfingomielina Fosfodiesterase/genética , Esfingomielina Fosfodiesterase/imunologia
12.
Arch Dermatol Res ; 312(1): 1-4, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31659432

RESUMO

Non-melanoma skin cancer primarily affects geriatric patients as evidenced by the fact that only 20% of these cancers are diagnosed in patients under the age of 60 years. Of importance, geriatric skin responds to procarcinogenic ultraviolet B radiation (UVB) in a manner that permits the establishment of tumor cells. Recent studies have indicated that wounding of geriatric skin with fractionated resurfacing lasers and dermabrasion upregulates fibroblast production of insulin-like growth factor-1 (IGF-1) and normalizes the procarcinogenic acute UVB response consisting of basal keratinocytes proliferating while still harboring unrepaired DNA damage. The present studies tested the ability of wounding with a commercially available microneedling device to upregulate IGF-1 levels and normalize the geriatric UVB response. Geriatric volunteers were treated with a microneedling device on buttock skin and 3 months later the IGF-1 levels and UVB responses tested in wounded vs control skin. Wounding via microneedling upregulated IGF-1 and resulted in lower levels of basal keratinocytes proliferating with unrepaired DNA damage. The ability of microneedling to protect against the formation of UVB-damaged proliferating keratinocytes indicates the potential of this wounding modality to reduce aging-associated non-melanoma skin cancer.


Assuntos
Envelhecimento , Pele/efeitos da radiação , Raios Ultravioleta , Idoso , Senescência Celular , Feminino , Humanos , Fator de Crescimento Insulin-Like I/genética , Fator de Crescimento Insulin-Like I/metabolismo , Queratinócitos/fisiologia , Masculino , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
13.
Artigo em Inglês | MEDLINE | ID: mdl-33088904

RESUMO

We investigated the variations in physician evaluation of skin photodamage based on a published photodamage scale. Of interest is the utility of a 10-level scale ranging from none and mild photodamage to actinic keratosis (AK). The dorsal forearms of 55 adult subjects with various amounts of photodamage were considered. Each forearm was independently evaluated by 15 board-certified dermatologists according to the Global Assessment Severity Scale ranging from 0 (less severe) to 9 (the most progressed stage of skin damage). Dermatologists rated the levels of photodamage based upon the photographs in blinded fashion. Results show substantial disagreement amongst the dermatologists on the severity of photodamage. Our results indicate that ratings could be more consistent if using a scale of less levels (5-levels or 3-levels). Ultimately, clinicians can use this knowledge to provide better interpretation of inter-rater evaluations and provide more reliable assessment and frequent monitoring of high-risk populations.

14.
Mol Cell Biol ; 26(17): 6403-11, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16914726

RESUMO

Members of the B7 family of cosignaling molecules regulate T-cell proliferation and effector functions by engaging cognate receptors on T cells. In vitro and in vivo blockade experiments indicated that B7-H4 (also known as B7S1 or B7x) inhibits proliferation, cytokine production, and cytotoxicity of T cells. B7-H4 binds to an unknown receptor(s) that is expressed on activated T cells. However, whether B7-H4 plays nonredundant immune regulatory roles in vivo has not been tested. We generated B7-H4-deficient mice to investigate the roles of B7-H4 during various immune reactions. Consistent with its inhibitory function in vitro, B7-H4-deficient mice mounted mildly augmented T-helper 1 (Th1) responses and displayed slightly lowered parasite burdens upon Leishmania major infection compared to the wild-type mice. However, the lack of B7-H4 did not affect hypersensitive inflammatory responses in the airway or skin that are induced by either Th1 or Th2 cells. Likewise, B7-H4-deficient mice developed normal cytotoxic T-lymphocyte reactions against viral infection. Thus, B7-H4 plays a negative regulatory role in vivo but the impact of B7-H4 deficiency is minimal. These results suggest that B7-H4 is one of multiple negative cosignaling molecules that collectively provide a fine-tuning mechanism for T-cell-mediated immune responses.


Assuntos
Antígeno B7-1/metabolismo , Animais , Doenças Autoimunes/imunologia , Proliferação de Células , Marcação de Genes , Inflamação/imunologia , Vírus da Influenza A/fisiologia , Leishmania major/fisiologia , Vírus da Coriomeningite Linfocítica/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/virologia , Células Th1/citologia , Células Th1/imunologia , Células Th1/parasitologia , Inibidor 1 da Ativação de Células T com Domínio V-Set
15.
Biomed Opt Express ; 10(9): 4676-4683, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31565518

RESUMO

We investigated the change in optical properties and vascular parameters to characterize skin tissue from mild photodamage to actinic keratosis (AK) with comparison to a published photodamage scale. Multi-wavelength spatial frequency domain imaging (SFDI) measurements were performed on the dorsal forearms of 55 adult subjects with various amounts of photodamage. Dermatologists rated the levels of photodamage based upon the photographs in blinded fashion to allow comparison with SFDI data. For characterization of statistical data, we used artificial neural networks. Our results indicate that optical and vascular parameters can be used to quantify photodamage and can discriminate between the stages as low, medium, and high grades, with the best performance of ∼70%, ∼76% and 80% for characterization of low- medium- and high-grade lesions, respectively. Ultimately, clinicians can use this noninvasive approach for risk assessment and frequent monitoring of high-risk populations.

16.
Contrib Microbiol ; 14: 42-67, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17684332

RESUMO

House dust mite (HDM) is the most pervasive indoor aeroallergen source worldwide. Allergens derived from HDM are associated with sensitization and allergic asthma. Allergic asthma is an immunologically driven disease characterized by a Th2-polarized immune response, eosinophilic inflammation, airway hyperreactivity, and remodeling. Animal models of asthma utilizing ovalbumin (OVA) exposure have afforded us considerable insight with respect to the mediators and cell types involved in allergic airway inflammation. However, OVA preparations and HDM are two vastly different materials. This chapter is specifically concerned with modeling responses to HDM exposure in mice. These studies have furnished new information and unlocked new lines of inquiry regarding biological responses to common aeroallergens. The complexity of HDM as an allergen source, with its plethora of protein and nonprotein immunogenic components, may influence the mechanisms underlying sensitization, inflammation and remodeling. Here, we will discuss this issue, along with giving critical thought to the use of experimental models.


Assuntos
Antígenos de Dermatophagoides/imunologia , Asma/imunologia , Modelos Animais de Doenças , Hipersensibilidade/imunologia , Pyroglyphidae/imunologia , Animais , Hiper-Reatividade Brônquica/imunologia , Humanos , Camundongos , Ovalbumina/imunologia , Células Th2/imunologia
17.
Can J Vet Res ; 71(2): 119-28, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17479775

RESUMO

Bovine leukemia virus (BLV) induces a persistent but latent infection in cattle. Viral latency is invoked by a protein known as plasma blocking factor (PBF) that is found in both bovine and human plasma. We report here on pathways that mediate latency in the presence of PBF. Reporter-gene constructs driven by the promoters of 6 retroviruses were used to measure the production of chloramphenicol acetyl transferase (CAT) in cell lines cultured with or without defibrinated bovine plasma. Plasma inhibited CAT production only in constructs containing an NFkappaB-binding element proximal to the initiation site (BLV, human immunodeficiency virus, and human T-cell leukemia virus). The promoters of Bovine immunodeficiency virus, Feline immunodeficiency virus, or Feline leukemia virus were not inhibited in the presence of bovine plasma. Using gel mobility shift assays, we demonstrated that activation of viral transcription upon stimulation with phorbol esters and ionomycin was mediated through the NFkappaB element and that this was abrogated in the presence of plasma. Furthermore, analysis of individual NFkappaB proteins in nuclear extracts of mononuclear cells or Jurkat cells showed that all 5 members of the NFkappaB family were upregulated in response to stimulation, but only p52 was significantly downregulated in the presence of bovine plasma. Thus, we infer that plasma effects are mediated through interference with either p52 translocation to the nucleus or p52 synthesis.


Assuntos
Antígenos de Neoplasias/biossíntese , Cloranfenicol O-Acetiltransferase/biossíntese , Regulação Viral da Expressão Gênica , Vírus da Leucemia Bovina/genética , Animais , Bovinos , Células Cultivadas , Feminino , Vírus da Leucemia Bovina/imunologia , Vírus da Leucemia Bovina/patogenicidade , NF-kappa B , Plasma , Sequências Repetidas Terminais , Transcrição Gênica , Transfecção , Latência Viral
18.
Biomed Opt Express ; 8(6): 3045-3052, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28663925

RESUMO

For prevention and accurate intervention planning, it is crucial to predict if lesions will progress towards cancer. In this study, we investigated the change in optical properties and vascular parameters to characterize skin tissue from mild photodamage to actinic keratosis (AK). Multi-wavelength spatial frequency domain imaging (SFDI) measurements were performed on three patients with clinically normal skin, as well as pre-cancerous actinic keratosis lesions. Our results indicate that there exist significant differences in both optical and vascular parameters between these patients, and that these parameters can be early biomarkers of neoplasia. Ultimately, clinicians can use this noninvasive approach for frequent monitoring of high-risk population.

19.
Vet Immunol Immunopathol ; 112(3-4): 302-8, 2006 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-16621030

RESUMO

Toll-like receptor (TLR)-4 is a transmembrane receptor for lipopolysaccharide, a highly pro-inflammatory component of the outer membrane of Gram-negative bacteria. To date, molecules of the TLR-4 signaling pathway have not been well characterized in cattle. The goal of this study was to clone and sequence the full-length coding regions of bovine genes involved in TLR-4 signaling including CASP8, IRAK1, LY96 (MD-2), TICAM2, TIRAP, TOLLIP and TRAF 6 and to position these genes, as well as MyD88 and TICAM1, on the bovine genome using radiation hybrid mapping. Results of this work indicate differences with a previously published bovine sequence for LY96 and a predicted sequence in the GenBank database for TIRAP based on the most recent assembly of the bovine genome. In addition, discrepancies between actual and predicted chromosomal map positions based on the Btau_2.0 genome assembly release were identified, although map positions were consistent with predicted locations based on the current bovine-human comparative map. Alignment of the bovine amino acid sequences with human and murine sequences showed a broad range in conservation, from 52 to 93%. Overall, this work should assist in the assembly and annotation of the bovine genome sequence, the identification of variations in genes critically involved in host innate immunity, and facilitate the study of TLR-4 signaling pathways in cattle.


Assuntos
Bovinos/imunologia , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia , Proteínas Adaptadoras de Transdução de Sinal/química , Proteínas Adaptadoras de Transdução de Sinal/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Caspase 8 , Caspases/química , Caspases/genética , Clonagem Molecular , Quinases Associadas a Receptores de Interleucina-1 , Peptídeos e Proteínas de Sinalização Intracelular/química , Peptídeos e Proteínas de Sinalização Intracelular/genética , Antígeno 96 de Linfócito/química , Antígeno 96 de Linfócito/genética , Fator 88 de Diferenciação Mieloide , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/genética , Mapeamento de Híbridos Radioativos/veterinária , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Transdução de Sinais/imunologia , Fator 6 Associado a Receptor de TNF/química , Fator 6 Associado a Receptor de TNF/genética
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