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1.
Nicotine Tob Res ; 15(9): 1511-8, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23482719

RESUMO

INTRODUCTION: The 2006 U.S. Surgeon General's Report found that there is no safe level of exposure to secondhand smoke (SHS). Many smokers attempt to protect others from exposure to SHS; however, it is difficult to assess effectiveness of these behavior changes. There is a need for personal monitoring devices that provide real-time SHS exposure data; at present, there is no device that measures ambient nicotine levels in real time. The development of such a sensor is the objective of this research. METHODS: A nicotine sensing film comprising the conductive polymer polyaniline was linked with a reporting layer, recording changes in chemiresistance due to adsorption of nicotine. Experiments were carried out in a microprocessor-controlled smoking chamber using sidestream smoke from standard reference cigarettes; up to 10 cigarettes were smoked simultaneously. The exposure chamber was calibrated for total suspended particle, carbon monoxide, and nicotine concentrations. RESULTS: We found significant real-time increases in the resistance of films upon exposure to SHS. The sensors were shown to be sensitive to the number of cigarettes consumed and ambient nicotine and demonstrated reasonable recovery between measurements. The sensors have sufficient sensitivity to detect off-gassing of nicotine or "thirdhand smoke." CONCLUSIONS: A sensing element has been developed that can reliably detect secondhand and thirdhand tobacco smoke in real time through the adsorption of ambient nicotine vapor. The device was calibrated to the number of smoked cigarettes and to nicotine concentration. Development of integrated personal sensors to record exposure to SHS using this technology is currently underway.


Assuntos
Nicotina/análise , Polímeros/química , Poluição por Fumaça de Tabaco/análise , Nicotina/química
2.
Cureus ; 15(11): e49367, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38146556

RESUMO

Objectives This study aimed to investigate the awareness and attitudes towards epidural analgesia (EA) among pregnant women in Taif City, Saudi Arabia. The rationale was to identify potential barriers to the acceptance and use of EA, which is an effective pain management option during labor. Methods We conducted a cross-sectional survey at a single healthcare center in Taif City. The participants, pregnant women visiting the center, were recruited using a convenience sampling method. Data collection was facilitated by a questionnaire distributed through a quick response (QR) code. The questionnaire assessed demographic information, awareness levels, previous exposure to EA, and personal attitudes toward its use during labor. Data analysis focused on quantifying the levels of awareness and identifying patterns in attitudes. Results The results revealed a low level of awareness about EA among the participants, with a significant proportion having never been exposed to it before the survey. Attitudes towards EA were varied, with some expressing openness to its use and others displaying apprehension or resistance, which appeared to be influenced by cultural perceptions and a lack of information. Conclusions The study highlighted a substantial lack of awareness and varied attitudes towards EA among pregnant women in Taif City. Educational interventions are necessary to increase awareness and address cultural misconceptions. The study's limited scope and potential sample bias suggest the need for broader culturally tailored research to inform strategies for improving the acceptance and utilization of labor analgesia.

3.
Br J Nutr ; 108(10): 1789-99, 2012 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-22293281

RESUMO

The purpose of the present study was to test the anti-inflammatory and blood glucose (BG)-regulating capacity of strawberries in a mouse model of diet-induced obesity. A total of thirty-six male C57BL/6J mice were randomly divided into four groups (nine mice per group). Mice were fed a low-fat diet (LF, 13 % fat), the LF supplemented with 2·6 % freeze-dried strawberry powder (LFSB), a high-fat diet (HF, 44 % fat) or the HF supplemented with 2·6 % strawberry powder (HFSB). Blood samples were collected to measure BG, inflammation and systemic markers for endocrine function of pancreas and adipose tissue. Splenocytes were harvested at the end of the study and activated with either anti-cluster of differentiation (CD) 3/anti-CD28 antibodies or lipopolysaccharide to test immune responsiveness. The HF increased non-fasted BG, insulin, soluble intracellular adhesion molecule-1, E-selectin, leptin, resistin and plasminogen activator protein-1 (P < 0·05). High dietary fat decreased IL-4 production from activated splenocytes (P < 0·05). BG concentrations were lower in the mice supplemented with SB (10·64 mmol/l) compared to the non-supplemented mice (11·37 mmol/l; P = 0·0022). BG values were approximately 6·5 % lower in the supplemented mice. Additionally, SB lowered plasma C-reactive protein in the LFSB group compared to the other three groups (P < 0·05). The dietary intake of SB approximated one human serving of strawberries. These results, although modest, support a promising role for dietary strawberries in reducing the risks associated with obesity and diabetes, and regulating the levels of inflammatory markers in non-obese individuals.


Assuntos
Glicemia/efeitos dos fármacos , Proteína C-Reativa/metabolismo , Dieta , Fragaria/química , Obesidade/sangue , Animais , Biomarcadores , Suplementos Nutricionais , Análise de Alimentos , Liofilização , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/metabolismo , Distribuição Aleatória , Baço/citologia
4.
Br J Nutr ; 108(5): 900-9, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22068016

RESUMO

Obesity is a strong risk factor for the development of CVD, hypertension and type 2 diabetes. The overall goal of the present pilot study was to feed strawberries, in the form of freeze-dried powder, to obese subjects to determine whether dietary strawberries beneficially altered lipid profiles and reduced blood markers of inflammation compared with a control intervention. A total of twenty healthy subjects (thirteen females and seven males) aged between 20 and 50 years with a BMI between 30 and 40 kg/m2 completed the present 7-week double-blind, randomised, cross-over trial. Each subject received a prepared diet 7 d/week for 7 weeks consisting of approximately 35 % of energy from fat, 20 % protein, 45 % carbohydrate and 14 g fibre. Blood was collected on days 1 and 8 for baseline information. After the first week, subjects were randomly assigned to the strawberry powder (equivalent to four servings of frozen strawberries) or control (strawberry-flavoured) intervention for 3 weeks. For the remaining 3 weeks, subjects crossed over to the opposite intervention. Blood was collected again at the end of weeks 3, 4, 6 and 7. A comprehensive chemistry panel, lipid profile analyses and measurement of inflammatory mediators were performed for each blood draw. A 3-week dietary intervention with strawberry powder reduced plasma concentrations of cholesterol and small HDL-cholesterol particles, and increased LDL particle size in obese subjects (P < 0·05). Dietary strawberry powder reduced risk factors for CVD, stroke and diabetes in obese volunteers, suggesting a potential role for strawberries as a dietary means to decrease obesity-related disease.


Assuntos
Biomarcadores/sangue , Dieta , Fragaria , Lipídeos/sangue , Obesidade/sangue , Adulto , Estudos Cross-Over , Método Duplo-Cego , Humanos , Inflamação , Masculino , Pós
5.
Front Public Health ; 8: 232, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32671009

RESUMO

Vitamin D deficiency and insufficiency (VDD) are widely recognized as risk factors for respiratory tract infections. Vitamin D influences expression of many genes with well-established relevance to airway infections and relevant to immune system function. Recently, VDD has been shown to be a risk factor for acquisition and severity of COVID-19. Thus, treating VDD presents a safe and inexpensive opportunity for modulating the severity of the disease. VDD is common in those over 60 years of age, many with co-morbid conditions and in people with skin pigmentation sufficient to reduce synthesis of vitamin D. Exposure to fine particulate air pollution is also associated with worse outcomes from COVID19. Vitamin D stimulates transcription of cathelicidin which is cleaved to generate LL37. LL37 is an innate antimicrobial with demonstrated activity against a wide range of microbes including envelope viruses. LL37 also modulates cytokine signaling at the site of infections. Fine particles in air pollution can interfere with LL37 destruction of viruses and may reduce effective immune signaling modulation by LL37. While vitamin D influences transcription of many immune related genes, the weakened antimicrobial response of those with VDD against SARS-CoV-2 may be in part due to reduced LL37. Conclusion: Vitamin D plays an important role reducing the impact of viral lung disease processes. VDD is an acknowledged public health threat that warrants population-wide action to reduce COVID-19 morbidity and mortality. While vitamin D influences transcription of many immune related genes, the weakened antimicrobial response of those with VDD against SARS-CoV-2 may be in part due to reduced LL37. Action is needed to address COVID-19 associated risks of air pollution from industry, transportation, domestic sources and from primary and second hand tobacco smoke.


Assuntos
Poluentes Atmosféricos , Peptídeos Catiônicos Antimicrobianos , Antivirais , COVID-19/etiologia , Material Particulado , Deficiência de Vitamina D/complicações , Humanos , Sistema Imunitário , SARS-CoV-2 , Catelicidinas
8.
Int J Nurs Educ Scholarsh ; 4: Article9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17402935

RESUMO

Student clinical practice is a significant and essential part of nursing education. Accordingly, clinical placements need to be positive and valuable. The purpose of this study was to describe newly-graduated nurses' perceptions of their student clinical intersession placements and how these placements impacted their functioning as graduate nurses. Inductive semantic analysis of the data revealed four themes: developing nursing skills and knowledge; preparing for future employment; experiencing supportive relationships; and experiencing realities of work-life. Educators must ensure that clinical placements are in an environment that is conducive to learning and promotes the personal and professional development of nursing students. Positive clinical experiences are more likely related to how valued and supported students feel than the physical aspects of a placement; thus, it is imperative educators assess and focus on providing placements that offer a supportive learning environment.


Assuntos
Competência Clínica , Bacharelado em Enfermagem/organização & administração , Conhecimentos, Atitudes e Prática em Saúde , Papel do Profissional de Enfermagem , Canadá , Escolha da Profissão , Emprego , Feminino , Humanos , Relações Interinstitucionais , Relações Interprofissionais , Masculino , Pesquisa em Educação em Enfermagem , Projetos Piloto
9.
Front Hum Neurosci ; 11: 67, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28270757

RESUMO

This single-arm non-randomized pilot study explores an intervention to improve the health of flight attendants (FA) exposed to second-hand cigarette smoke prior to the smoking ban on commercial airlines. This group exhibits an unusual pattern of long-term pulmonary dysfunction. We report on Phase I of a two-phase clinical trial; the second Phase will be a randomized controlled trial testing digital delivery of the intervention. Subjects were recruited in the Northeastern US; testing and intervention were administered in 4 major cities. The intervention involved 12 h of training in Meditative Movement practices. Based on recent research on the effects of nicotine on fear learning, and the influence of the autonomic nervous system on immune function, our hypothesis was that this training would improve autonomic function and thus benefit a range of health measures. Primary outcomes were the 6-min walk test and blood levels of C-reactive protein. Pulmonary, cardiovascular, autonomic, and affective measures were also taken. Fourteen participants completed the training and post-testing. There was a 53% decrease in high sensitivity C-Reactive Protein (p ≤ 0.05), a 7% reduction in systolic blood pressure (p ≤ 0.05), a 13% increase in the 6-min walk test (p ≤ 0.005), and significant positive changes in several other outcomes. These results tend to confirm the hypothesized benefits of MM training for this population, and indicate that autonomic function may be important in the etiology and treatment of their symptoms. No adverse effects were reported. This trial is registered at ClinicalTrials.gov (https://clinicaltrials.gov/ct2/show/NCT02612389/), and is supported by a grant from the Flight Attendant Medical Research Institute (FAMRI).

10.
Front Hum Neurosci ; 9: 178, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25883565

RESUMO

Basic to all motile life is a differential approach/avoid response to perceived features of environment. The stages of response are initial reflexive noticing and orienting to the stimulus, preparation, and execution of response. Preparation involves a coordination of many aspects of the organism: muscle tone, posture, breathing, autonomic functions, motivational/emotional state, attentional orientation, and expectations. The organism organizes itself in relation to the challenge. We propose to call this the "preparatory set" (PS). We suggest that the concept of the PS can offer a more nuanced and flexible perspective on the stress response than do current theories. We also hypothesize that the mechanisms of body-mind therapeutic and educational systems (BTES) can be understood through the PS framework. We suggest that the BTES, including meditative movement, meditation, somatic education, and the body-oriented psychotherapies, are approaches that use interventions on the PS to remedy stress and trauma. We discuss how the PS can be adaptive or maladaptive, how BTES interventions may restore adaptive PS, and how these concepts offer a broader and more flexible view of the phenomena of stress and trauma. We offer supportive evidence for our hypotheses, and suggest directions for future research. We believe that the PS framework will point to ways of improving the management of stress and trauma, and that it will suggest directions of research into the mechanisms of action of BTES.

11.
Front Psychol ; 6: 93, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25699005

RESUMO

Here we present a theory of human trauma and chronic stress, based on the practice of Somatic Experiencing(®) (SE), a form of trauma therapy that emphasizes guiding the client's attention to interoceptive, kinesthetic, and proprioceptive experience. SE™ claims that this style of inner attention, in addition to the use of kinesthetic and interoceptive imagery, can lead to the resolution of symptoms resulting from chronic and traumatic stress. This is accomplished through the completion of thwarted, biologically based, self-protective and defensive responses, and the discharge and regulation of excess autonomic arousal. We present this theory through a composite case study of SE treatment; based on this example, we offer a possible neurophysiological rationale for the mechanisms involved, including a theory of trauma and chronic stress as a functional dysregulation of the complex dynamical system formed by the subcortical autonomic, limbic, motor and arousal systems, which we term the core response network (CRN). We demonstrate how the methods of SE help restore functionality to the CRN, and we emphasize the importance of taking into account the instinctive, bodily based protective reactions when dealing with stress and trauma, as well as the effectiveness of using attention to interoceptive, proprioceptive and kinesthetic sensation as a therapeutic tool. Finally, we point out that SE and similar somatic approaches offer a supplement to cognitive and exposure therapies, and that mechanisms similar to those discussed in the paper may also be involved in the benefits of meditation and other somatic practices.

12.
Front Psychol ; 6: 423, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25926804

RESUMO

[This corrects the article on p. 93 in vol. 6, PMID: 25699005.].

13.
Front Psychiatry ; 6: 185, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26793127

RESUMO

Smokers and individuals exposed to second-hand cigarette smoke have a higher risk of developing chronic sinus and bronchial infections. This suggests that cigarette smoke (CS) has adverse effects on immune defenses against pathogens. Epithelial cells are important in airway innate immunity and are the first line of defense against infection. Airway epithelial cells not only form a physical barrier but also respond to the presence of microbes by secreting antimicrobials, cytokines, and chemokines. These molecules can lyse infectious microorganisms and/or provide signals critical to the initiation of adaptive immune responses. We examined the effects of CS on antimicrobial secretions of primary human nasal epithelial cells (PHNECs). Compared to non-CS-exposed individuals, PHNEC from in vivo CS-exposed individuals secreted less chemokine ligand (C-C motif) 20 (CCL20), Beta-defensin 1 (BD-1), and SLPI apically, less BD-1 and SLPI basolaterally, and more CCL20 basolaterally. Cigarette smoke extract (CSE) exposure in vitro decreased the apical secretion of CCL20 and beta-defensin 1 by PHNEC from non-CS-exposed individuals. Exposing PHNEC from non-CS exposed to CSE also significantly decreased the levels of many mRNA transcripts that are involved in immune signaling. Our results show that in vivo or in vitro exposure to CS alters the secretion of key antimicrobial peptides from PHNEC, but that in vivo CS exposure is a much more important modifier of antimicrobial peptide secretion. Based on the gene expression data, it appears that CSE disrupts multiple immune signaling pathways in PHNEC. Our results provide mechanistic insight into how CS exposure alters the innate immune response and increases an individual's susceptibility to pathogen infection.

14.
Am J Trop Med Hyg ; 59(4): 513-8, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9790420

RESUMO

Malariometric surveys were conducted during July 1996 in native Dayak villages and predominantly Javanese transmigration settlements in Ketapang district of West Kalimantan, Indonesia. Malaria prevalence ranged from 0.9% to 2.7% in Dayak villages and from 1% to 20% in the transmigration settlements. Plasmodium falciparum accounted for 67% of the cases among Dayaks but P. vivax was dominant among transmigrants, accounting for more than 72% of the infections. Chloroquine sensitivity/resistance was assessed by 28-day in vivo testing of uncomplicated malaria infections and measurement of chloroquine blood levels in cases where parasitemias reappeared within the 28-day test period. Resistance was based on the appearance of asexual parasites against chloroquine plus desethylchloroquine levels exceeding the minimally effective whole blood concentrations proposed for sensitive parasite strains (P. vivax, 100 ng/ml; P. falciparum, 200 ng/ml). All parasitemias cleared initially within four days of beginning supervised chloroquine therapy (25 mg base/kg over a 48-hr period), but asexual parasites reappeared within 28 days in 27 of 52 P. vivax and three of 12 P. falciparum cases. Chloroquine blood levels at the time of recurrent parasitemias revealed resistance in 12 of the 27 P. vivax cases and in one of the three P. falciparum cases. Genotypes of nine of the 12 recurrent P. vivax isolates matched with their primary isolates and ruled out reinfection. These findings establish the presence of chloroquine-resistant P. vivax on the island of Borneo. The pattern of malaria and the high frequency of chloroquine resistance by P. vivax at the West Kalimantan location may relate to demographic, ecologic, agricultural, and socioeconomic changes associated with transmigration.


Assuntos
Antimaláricos/farmacologia , Cloroquina/farmacologia , Plasmodium vivax/efeitos dos fármacos , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Cloroquina/farmacocinética , Resistência a Medicamentos , Humanos , Indonésia/epidemiologia , Lactente , Malária Vivax/epidemiologia , Prevalência , Migrantes
15.
Trans R Soc Trop Med Hyg ; 89(3): 316-8, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7660448

RESUMO

A study to monitor ivermectin acceptability and post-treatment reactions during mass community distribution was carried out in eastern Sudan, where severe reactive onchodermatitis is prevalent. Of 1081 individuals eligible for treatment, 1076 (99.5%) accepted the ivermectin. Post-treatment reactions were monitored by self reporting, 5 d after a single dose of about 150 micrograms/kg (range 103-200 micrograms/kg); 230 persons reported adverse events (21.4%). No reaction was rated as severe. The most common problem was itching with cutaneous papular eruptions (16.2%). Local oedematous swelling was the second most common and the most slowly resolving complaint (5.4%), followed by musculoskeletal pain. There was a high acceptance rate of the treatment and remarkable tolerance of the post-treatment effects, probably due to efforts made to prepare the community to expect reactions to ivermectin, widespread awareness of the beneficial effects of treatment by villagers who had participated in clinical trials previously, and the encouragement we gave to the population to become involved in improvement of their health care services. Single doses of ivermectin resulted in good clinical responses and created much goodwill among villagers. Improvements in physical fitness, ability to work, and freedom from musculoskeletal pain were reported at the 3 months' follow-up. We recommend that, during mass distribution of ivermectin, community involvement in planning overall health improvement should be included, since the treatment initiates the process well. In areas where sowda syndrome is prevalent, medical surveillance for 3 d or more should be considered.


Assuntos
Ivermectina/efeitos adversos , Onchocerca volvulus , Oncocercose/tratamento farmacológico , Adolescente , Adulto , Idoso , Animais , Criança , Pré-Escolar , Feminino , Humanos , Ivermectina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Aceitação pelo Paciente de Cuidados de Saúde , Sudão
16.
Int J Gynaecol Obstet ; 35(3): 221-4, 1991 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1677625

RESUMO

This study represents the first of its kind in Kuwait. Two preparations of prostaglandin E2 (PGE2) have been compared as agents for induction of labor. In a randomized controlled study of 200 women of low parity and unfavorable cervical induction features induction of labor by means of a single vaginal tablets of PGE2 was compared with locally prepared PGE2 vaginal pessaries. The gradual increase of uterine contractions and the establishment of labor in a similar way to that observed during spontaneous labor was more apparent after PGE2 tablets. Labor induction was successful in 80% of patients in PGE2 tablet group compared with 59% in PGE2 pessaries group. The incidence of cesarean section was equal in both groups (4%), but none was performed due to uterine hyperactivity. The data presented indicate that the PGE2 vaginal tablet is safe and effective in induction of labor in healthy women at term.


Assuntos
Dinoprostona/administração & dosagem , Trabalho de Parto Induzido/métodos , Pessários/normas , Administração Intravaginal , Adulto , Âmnio/cirurgia , Cesárea/estatística & dados numéricos , Parto Obstétrico/métodos , Parto Obstétrico/estatística & dados numéricos , Dinoprostona/uso terapêutico , Feminino , Humanos , Gravidez , Vácuo-Extração/estatística & dados numéricos
17.
Front Hum Neurosci ; 8: 205, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24782738

RESUMO

Over the past decades, cognitive neuroscience has witnessed a shift from predominantly disembodied and computational views of the mind, to more embodied and situated views of the mind. These postulate that mental functions cannot be fully understood without reference to the physical body and the environment in which they are experienced. Within the field of contemplative science, the directing of attention to bodily sensations has so far mainly been studied in the context of seated meditation and mindfulness practices. However, the cultivation of interoceptive, proprioceptive and kinesthetic awareness is also said to lie at the core of many movement-based contemplative practices such as Yoga, Qigong, and Tai Chi. In addition, it likely plays a key role in the efficacy of modern somatic therapeutic techniques such as the Feldenkrais Method and the Alexander Technique. In the current paper we examine how these practices are grounded in the concepts of embodiment, movement and contemplation, as we look at them primarily through the lens of an enactive approach to cognition. Throughout, we point to a series of challenges that arise when Western scientists study practices that are based on a non-dualistic view of mind and body.

18.
Front Psychiatry ; 4: 71, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23898306

RESUMO

This review focuses on Meditative Movement (MM) and its effects on anxiety, depression, and other affective states. MM is a term identifying forms of exercise that use movement in conjunction with meditative attention to body sensations, including proprioception, interoception, and kinesthesis. MM includes the traditional Chinese methods of Qigong (Chi Kung) and Taijiquan (Tai Chi), some forms of Yoga, and other Asian practices, as well as Western Somatic practices; however this review focuses primarily on Qigong and Taijiquan. We clarify the differences between MM and conventional exercise, present descriptions of several of the key methodologies of MM, and suggest how research into these practices may be approached in a systematic way. We also present evidence for possible mechanisms of the effects of MM on affective states, including the roles of posture, rhythm, coherent breathing, and the involvement of specific cortical and subcortical structures. We survey research outcomes summarized in reviews published since 2007. Results suggest that MM may be at least as effective as conventional exercise or other interventions in ameliorating anxiety and depression; however, study quality is generally poor and there are many confounding factors. This makes it difficult to draw definitive conclusions at this time. We suggest, however, that more research is warranted, and we offer specific suggestions for ensuring high-quality and productive future studies.

19.
Front Physiol ; 4: 132, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23781205

RESUMO

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide. While the primary risk factor for COPD is cigarette smoke exposure, vitamin D deficiency has been epidemiologically implicated as a factor in the progressive development of COPD-associated emphysema. Because of difficulties inherent to studies involving multiple risk factors in the progression of COPD in humans, we developed a murine model in which to study the separate and combined effects of vitamin D deficiency and cigarette smoke exposure. During a 16-week period, mice were exposed to one of four conditions, control diet breathing room air (CD-NS), control diet with cigarette smoke exposure (CD-CSE), vitamin D deficient diet breathing room air (VDD-NS) or vitamin D deficient diet with cigarette smoke exposure (VDD-CSE). At the end of the exposure period, the lungs were examined by a pathologist and separately by morphometric analysis. In parallel experiments, mice were anesthetized for pulmonary function testing followed by sacrifice and analysis. Emphysema (determined by an increase in alveolar mean linear intercept length) was more severe in the VDD-CSE mice compared to control animals and animals exposed to VDD or CSE alone. The VDD-CSE and the CD-CSE mice had increased total lung capacity and increased static lung compliance. There was also a significant increase in the matrix metalloproteinase-9: tissue inhibitor of metalloproteinases-1 (TIMP-1) ratio in VDD-CSE mice compared with all controls. Alpha-1 antitrypsin (A1AT) expression was reduced in VDD-CSE mice as well. In summary, vitamin D deficiency, when combined with cigarette smoke exposure, seemed to accelerate the appearance of emphysemas, perhaps by virtue of an increased protease-antiprotease ratio in the combined VDD-CSE animals. These results support the value of our mouse model in the study of COPD.

20.
Acta Biomater ; 7(5): 2270-5, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21295164

RESUMO

New processing routes and characterization techniques underpin further growth of biomaterials for improved performance and multifunctionality. This study investigates the characteristics and solubility of amorphous calcium phosphate (ACP) printed splats. Splats made from 20 to 60 µm molten hydroxyapatite particles were classified for shape (rounded/splashed) and cracking. Recoil of the spread droplet created a bowl-shaped splat. This has previously not been observed and could be related to the longer solidification time associated with solidification to an ACP. A central depression was created from 20 µm particles, but a bowl-shaped splat from 60 µm particles. Cracking was more prevalent for splats that solidified with an edge discontinuity. Splats immersed in pH 7.3 tris buffer displayed dissolution followed by cracking. Cracking continued over a period of 15 min as dissolution induced more cracks. Further degradation occurred by delamination of splat segments. Delamination accelerated the process of splat removal. Applied to thermal spray coatings, this highlights topography and dissolution at the splat level. The use of separate splats can potentially be used as a biolayer where splats are separate, in a line or on top of each other.


Assuntos
Fosfatos de Cálcio/análise , Teste de Materiais/métodos , Soluções Tampão , Durapatita/análise , Pós , Solubilidade
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