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1.
J Bus Res ; 161: 113839, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36919146

RESUMO

The impact of pandemics on the tourism industry should be explored from the perspective of those who will travel, go to the tourist places on vacation, and avail services from tourism and hospitality-related organizations. This study has aimed to identify the reasons for the changed human psychology towards tourism during the COVID-19 Pandemic to develop an attitude-behavioral model. This investigation thus conducted an extensive empirical study among tourists to capture their social, emotional, and financial beliefs. The research then examined the measurement model through confirmatory factor analysis (CFA) before investigating the cause-effect relationship through the structural model. Analysis revealed that the negative effect of attitude on behavioral intention toward this new equilibrium is controlled by the emotional aspect of attitude. Furthermore this paper made several contributions to the literature on human psychology, crisis management, human behavior, marketing, and tourism.

2.
Mar Biol ; 169(6): 78, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35607419

RESUMO

The protective carapace of Skogsbergia lerneri, a marine ostracod, is scratch-resistant and transparent. The compositional and structural organisation of the carapace that underlies these properties is unknown. In this study, we aimed to quantify and determine the distribution of chemical elements and chitin within the carapace of adult ostracods, as well as at different stages of ostracod development, to gain insight into its composition. Elemental analyses included X-ray absorption near-edge structure, X-ray fluorescence and X-ray diffraction. Nonlinear microscopy and spectral imaging were performed to determine chitin distribution within the carapace. High levels of calcium (20.3%) and substantial levels of magnesium (1.89%) were identified throughout development. Amorphous calcium carbonate (ACC) was detected in carapaces of all developmental stages, with the polymorph, aragonite, identified in A-1 and adult carapaces. Novel chitin-derived second harmonic generation signals (430/5 nm) were detected. Quantification of relative chitin content within the developing and adult carapaces identified negligible differences in chitin content between developmental stages and adult carapaces, except for the lower chitin contribution in A-2 (66.8 ± 7.6%) compared to A-5 (85.5 ± 10%) (p = 0.03). Skogsbergia lerneri carapace calcium carbonate composition was distinct to other myodocopid ostracods. These calcium polymorphs and ACC are described in other biological transparent materials, and with the consistent chitin distribution throughout S. lerneri development, may imply a biological adaptation to preserve carapace physical properties. Realisation of S. lerneri carapace synthesis and structural organisation will enable exploitation to manufacture biomaterials and biomimetics with huge potential in industrial and military applications.

3.
SAGE Open Nurs ; 8: 23779608221095432, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35574269

RESUMO

Introduction: Innovative work behavior of nurses is essential to deliver affordable quality healthcare services. Diversity climate and job crafting are a few of the supportive managerial strategies that can be applied to cultivate the innovative capacity of nurses. Objective: Aim for the current study is to: (a) examine the role of diversity climate in cultivating innovative work behavior of nurses directly; and (b) indirectly through job crafting. Methods: For this study data was collected through cross-sectional design employing simple random sampling using structured questionnaires from 283 nurses. Data was analyzed using SPSS.Amos.21. Results: Results revealed the positive influence of diversity climate on innovative work behavior directly (γ = 0.51, p < .001) and indirectly through job crafting (ρ = 0.235, p < .001). Conclusion: The current study revealed that diversity climate significantly influences the innovative work behavior of employees directly and indirectly through Job crafting. Healthcare management can integrate diversity management policies and job crafting techniques in their strategies to foster innovative work behavior of nurses.

4.
Mar Biol ; 169(3): 35, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35221378

RESUMO

The Skogsbergia lerneri is a marine ostracod which possesses a carapace that is both protective and transparent. Since development of this carapace and how it is maintained in the adult is not known, the aim of this investigation was to carry out an in-depth ultrastructural study of the ostracod carapace at different developmental stages. Standard transmission electron microscopy and novel serial block face scanning electron microscopy (SBF-SEM) were undertaken to discern carapace ultrastructure in both two and three dimensions. Analysis revealed a carapace consisting of the same basic layer structure as other myodocopid ostracods, namely an epicuticle, exocuticle, endocuticle and membranous layer, but with a thinner adult carapace of mean thickness of 19.2 ± 1.78 µm, n = 5. The carapace layers, except for instar 1 ostracods, had similar relative proportions throughout development. The endocuticle and membranous layer thickened through advancing developmental stages due to an increase in calcified crystalline polyhedrons and a greater number of chitinous lamellae in the membranous layer. Crystalline polyhedron dimensions were significantly smaller near the boundary with the membranous layer. The borders between the carapace layers were indistinct; SBF-SEM revealed an abundance of epicuticle projections into the exocuticle and apparent gradual merging at the boundary of the exocuticle and the endocuticle. Here, we discuss how the S. lerneri carapace layer structure has evolved to serve a specific mechanical function, allowing surface protection and rigidity. In addition, we suggest that the lack of pigment and graduated layer boundaries contribute to the transparency of the carapace. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00227-021-04006-7.

5.
Mymensingh Med J ; 30(3): 769-779, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34226467

RESUMO

The huge numbers of non-healthcare personnel (non-HCP) who get infected by corona virus disease 2019 (COVID-19) not only paralyze health care systems but also put health care personnel (HCP) at potential risk globally. Objective of the study was to compare the Healthcare personnel (HCP) and non-HCP COVID-19 cases. This prospective observational study was carried out in National Heart Foundation Hospital and Research Institute of Bangladesh from March 08, 2020 to July 20, 2020. During this study period all admitted non-HCP who subsequently was diagnosed as COVID-19 positive by rRT-PCR and HCP of this hospital, who experienced fever or respiratory symptoms or came in close contact with COVID-19 patients at home or their workplace and become COVID-19 positive, were included. Out of 320 infected patients, 181(56.6%) patients were non-HCP and 139(43.4%) were HCP. Non-HCP were older than HCP (Mean age: 52.95±13.82 years vs. 34.08±11.11 years; p=0.001). Non-HCP were predominantly male and HCP were predominantly female (73.5% vs. 41% & 26.5% vs. 59%; p=0.001). Non-HCP had more risk factors and co-morbidities than HCP (p=0.001). Typical symptoms of COVID-19 such as fever and cough were prevalent in HCP. More aggressive treatment was required for non-HCP. Non-HCP had more severe disease and higher case fatality rate (9.4% vs. 0.7%; p=0.001) than HCP. Disease severity (OR 0.03, 95% CI 0.01-0.15) and DM (OR 0.09, 95% CI 0.01-0.94) were the independent predictor of mortality. Non-HCP was older in age, predominantly male and had more co-morbidities than HCP. Typical symptoms of COVID-19 were prevalent in HCP. Non-HCP had more severe disease and higher case fatality rate than HCP.


Assuntos
COVID-19 , Adulto , Idoso , Bangladesh/epidemiologia , Atenção à Saúde , Feminino , Hospitais , Humanos , Masculino , Pessoa de Meia-Idade , SARS-CoV-2
6.
Nanomaterials (Basel) ; 11(3)2021 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-33800395

RESUMO

In this study we mimic the unique, transparent protective carapace (shell) of myodocopid ostracods, through which their compound eyes see, to demonstrate that the carapace ultrastructure also provides functions of strength and protection for a relatively thin structure. The bulk ultrastructure of the transparent window in the carapace of the relatively large, pelagic cypridinid (Myodocopida) Macrocypridina castanea was mimicked using the thin film deposition of dielectric materials to create a transparent, 15 bi-layer material. This biomimetic material was subjected to the natural forces withstood by the ostracod carapace in situ, including scratching by captured prey and strikes by water-borne particles. The biomimetic material was then tested in terms of its extrinsic (hardness value) and intrinsic (elastic modulus) response to indentation along with its scratch resistance. The performance of the biomimetic material was compared with that of a commonly used, anti-scratch resistant lens and polycarbonate that is typically used in the field of transparent armoury. The biomimetic material showed the best scratch resistant performance, and significantly greater hardness and elastic modulus values. The ability of biomimetic material to revert back to its original form (post loading), along with its scratch resistant qualities, offers potential for biomimetic eye protection coating that could enhance material currently in use.

7.
Mymensingh Med J ; 29(2): 488-494, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32506111

RESUMO

Since the first recorded case of SARS-CoV-2 in Bangladesh on 8th March 2020, COVID-19 has spread widely through different regions of the country, resulting in a necessity to re-evaluate the delivery of cardiovascular services, particularly procedures pertaining to interventional cardiology in resource-limited settings. Given its robust capacity for human-to-human transmission and potential of being a nosocomial source of infection, the disease has specific implications on healthcare systems and health care professionals faced with performing essential cardiac procedures in patients with a suspected or confirmed diagnosis of COVID-19. The limited resources in terms of cardiac catheterization laboratories that can be designated to treat only COVID positive patients are further compounded by the additional challenges of unavailability of widespread rapid testing on-site at tertiary cardiac hospitals in Bangladesh. This document prepared for our nation by the Bangladesh Society of Cardiovascular Interventions (BSCI) is intended to serve as a clinical practice guideline for cardiovascular health care professionals, with a focus on modifying standard practice of care during the COVID-19 pandemic, in order to ensure continuation of adequate and timely treatment of cardiovascular emergencies avoiding hospital-based transmission of SARS-COV-2 among healthcare professionals and the patients. This is an evolving document based on currently available global data and is tailored to healthcare systems in Bangladesh with particular focus on, but not limited to, invasive cardiology facilities (cardiac catheterization, electrophysiology & pacing labs). This guideline is limited to the provision of cardiovascular care, and it is expected that specific targeted pharmaco-therapeutics against SARS-CoV-2 be prescribed as stipulated by the National Guidelines on Clinical Management of Corona virus Disease 2019 (COVID-19) published by the Director General of Health Services, Ministry of Health and Family Welfare of Bangladesh.


Assuntos
Doenças Cardiovasculares , Procedimentos Cirúrgicos Cardiovasculares , Infecções por Coronavirus , Pandemias , Pneumonia Viral , Bangladesh , Betacoronavirus , COVID-19 , Doenças Cardiovasculares/terapia , Infecções por Coronavirus/complicações , Infecções por Coronavirus/epidemiologia , Humanos , Pneumonia Viral/complicações , Pneumonia Viral/epidemiologia , SARS-CoV-2
8.
Vet Med Sci ; 4(2): 126-132, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29851310

RESUMO

Canine monocytic ehrlichiosis is a tick-borne disease caused by an intracellular alpha-proteobacterium, Ehrlichia canis, which replicates within mononuclear cells in the host. This study was designed to use a polymerase chain reaction (PCR) protocol for the molecular detection of E. canis by the amplification of a portion of its 16S rRNA gene, as well as the effects of this alpha-proteobacterium on the haematological parameters of the sampled dogs and the risk factors associated with E. canis infection. A total of 151 blood samples were collected from dogs of various breeds at three sampling sites (Lahore, Rawalpindi/Islamabad and Multan) in Punjab, Pakistan. Data regarding the epidemiological factors (including age, gender, breed, body temperature, deworming, vaccination, mucous membrane status, hydration status, the presence of haematuria and tick infestation) were collected through a questionnaire at the time of sample collection. A 400 bp DNA fragment of the 16S rRNA gene of E. canis was amplified from 42 dog blood samples (28% of the total), [Lahore (N = 24), Rawalpindi/Islamabad (N = 13) and Multan (N = 05)] through PCR. Data analysis revealed that the character of the animals (age, sex and breed) had no significant association (P > 0.05) with the presence of E. canis. Various haematological parameters were also compared, and the results revealed that all of the parameters remained unaffected, except significantly lower white blood cell counts (P = 0.004) in E. canis-positive blood samples, as compared with the control group. We concluded that this is the first molecular confirmation of canine infection by E. canis using PCR. Moreover, no specific epidemiological parameter was found associated with the prevalence of E. canis in dogs.


Assuntos
Doenças do Cão/epidemiologia , Ehrlichia canis/isolamento & purificação , Ehrlichiose/veterinária , Fatores Etários , Animais , DNA Bacteriano/genética , Doenças do Cão/microbiologia , Cães/genética , Ehrlichia canis/genética , Ehrlichiose/epidemiologia , Ehrlichiose/microbiologia , Feminino , Contagem de Leucócitos/veterinária , Masculino , Paquistão/epidemiologia , Prevalência , RNA Ribossômico 16S/genética , Fatores Sexuais
9.
Indian Heart J ; 69(5): 607-612, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29054184

RESUMO

OBJECTIVE: Chronic symptomatic sinus node dysfunction (SND), the most common bradyarrhythmia, can be effectively managed by permanent cardiac pacing. Yet the care pathway and barriers to adoption of pacing therapy are not well understood - particularly in low volume implanting countries. The IMPROVE Brady study is a quality improvement initiative being conducted at centers in South Asia, Latin America, and Russia. We assessed the rates of SND diagnosis and pacemaker treatment for SND in the South Asia cohort. METHODS: The prospective study enrolled patients with heart rate of ≤50 beats per minute presenting with symptoms including syncope, dizziness, and/or dyspnea from ten centers in India and Bangladesh. Patients were followed to identify the proportion diagnosed with SND and subsequently treated with pacemaker therapy. RESULTS: A total of 508 patients meeting criteria were enrolled and followed on average for 8.3±8.0months. Patients were on average 58 years of age, 77% were male, and 91% had completed at least primary education. An SND diagnosis was made in 368 (72%) of patients, with the majority (80%) of diagnoses occurring within 1 month of enrollment. Of the patients with an SND diagnosis, 63 (17%) were treated with a pacemaker. Reasons for not receiving treatment were: subject refusal or deferred decision (45%), unaffordability (34%), physician determined - not-indicated (20%), and other (1%). Older age, female gender, history of hypertension, lower resting heart rate, and syncopal or pre-syncopal symptoms were associated with a higher probability of implant. CONCLUSIONS: In a care pathway assessment for the diagnosis and treatment of symptomatic SND in South Asia only 1 in 6 patients received pacemaker indicated therapy, largely due to patient refusal and physician decision. Phase II of the study will be aimed to improve this treatment rate.


Assuntos
Estimulação Cardíaca Artificial/estatística & dados numéricos , Frequência Cardíaca/fisiologia , Avaliação de Resultados em Cuidados de Saúde , Marca-Passo Artificial/estatística & dados numéricos , Vigilância de Produtos Comercializados/métodos , Síndrome do Nó Sinusal/terapia , Ásia/epidemiologia , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Síndrome do Nó Sinusal/epidemiologia , Síndrome do Nó Sinusal/fisiopatologia , Fatores de Tempo
10.
Trop Biomed ; 34(3): 648-656, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33592933

RESUMO

Streptococcus pyogenes or Group A Streptococcus (GAS) is a re-emerging pathogen of significant public health importance. We present trends in GAS blood cultures over a 10 year period in Pakistan and characteristics of hospitalized patients with GAS sepsis over three years at a tertiary care hospital in Karachi, Pakistan. Blood cultures positive for GAS from 2004 -2014 were recorded at the clinical microbiology laboratory of the Aga Khan University and studied for trends in positivity rates. Medical records of patients hospitalized at the Aga Khan University hospital from 2012-2014 were also examined for clinical features and outcomes. GAS trends show a steady rate of blood culture positivity over 11 years, with higher rates in those >50 years, and seasonality favouring winter months. Case fatality rate in the hospitalized cohort was 34.1% (n= 14; of 41 patients). Malignancy predominated as the underlying predisposing factor among the 15-49 age group. Presence of sepsis was an independent predictor of mortality in GAS bacteremia. Studies of GAS trends in developing regions are important to inform changing epidemiology. GAS septic shock continues to have high case fatality despite antibiotic treatment. Early recognition, aggressive, goal-directed therapy for sepsis and prevention are possible control measures to prevent high mortality.

11.
Int J Mycobacteriol ; 5(4): 412-416, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27931682

RESUMO

OBJECTIVE/BACKGROUND: Fluoroquinolones (FQs) are important anti-tuberculous drugs for the treatment of multidrug-resistant (MDR) tuberculosis. Resistance to FQs leads to fewer options for treatment of tuberculosis (TB), and infection with such strains may also require longer treatment duration. Trends of resistance in Mycobacterium tuberculosis (MTB) are indicators of MTB-resistance evolution. Drivers of such resistance need to be understood and studied to inform preventive strategies. METHODS: Here, we present FQ-resistance rates and trends in Pakistan from 2010 to 2015 and compare rates with FQ-consumption data and rates in other community pathogens. RESULTS: Our results reveal a recent decrease in FQ-resistance rates in MTB, but an increase in resistance for Haemophilus influenzae and Shigella spp. Correlation of FQ resistance with FQ consumption at the population level was weak for MTB, although strong associations were noted for H. influenzae and Shigella spp. CONCLUSION: We discuss the possible reasons for the decrease in resistance rates in TB, putative drivers of resistance other than volume of FQ consumption, and the possible impact of the National Tuberculosis Programme and drug regulatory activities.


Assuntos
Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Farmacorresistência Bacteriana , Uso de Medicamentos , Fluoroquinolonas/farmacologia , Fluoroquinolonas/uso terapêutico , Mycobacterium tuberculosis/efeitos dos fármacos , Haemophilus influenzae/efeitos dos fármacos , Humanos , Paquistão , Shigella/efeitos dos fármacos
12.
Philos Trans A Math Phys Eng Sci ; 374(2073)2016 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-27354735

RESUMO

Three species of cactus whose spines act as dew harvesters were chosen for this study: Copiapoa cinerea var. haseltoniana, Mammillaria columbiana subsp. yucatanensis and Parodia mammulosa and compared with Ferocactus wislizenii whose spines do not perform as dew harvesters. Time-lapse snapshots of C. cinerea showed movement of dew droplets from spine tips to their base, even against gravity. Spines emanating from one of the areoles of C. cinerea were submerged in water laced with fluorescent nanoparticles and this particular areole with its spines and a small area of stem was removed and imaged. These images clearly showed that fluorescent water had moved into the stem of the plant. Lines of vascular bundles radiating inwards from the surface areoles (from where the spines emanate) to the core of the stem were detected using magnetic resonance imaging, with the exception of F. wislizenii that does not harvest dew on its spines. Spine microstructures were examined using SEM images and surface roughness measurements (Ra and Rz) taken of the spines of C. cinerea It was found that a roughness gradient created by tapered microgrooves existed that could potentially direct surface water from a spine tip to its base.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'.


Assuntos
Cactaceae/anatomia & histologia , Cactaceae/química , Estruturas Vegetais/anatomia & histologia , Estruturas Vegetais/química , Água/química , Anisotropia , Difusão , Gravitação
13.
Expert Rev Clin Pharmacol ; 9(2): 329-38, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26582317

RESUMO

BACKGROUND AND AIMS: vitamin D deficiency (25-hydroxyvitamin D) affects over one billion people worldwide. Vitamin D deficiency results in progression of osteoporosis as well as other conditions. Previous studies have shown high rates of vitamin D deficiency in Pakistan despite appreciable levels of sunshine. However, none have assessed vitamin D deficiency across all age groups, genders, incomes, and locations to guide future strategies. METHODS: Questionnaire and blood sampling among 4830 randomly selected citizens. RESULTS: High levels of deficiency among all age groups, genders, income levels, and locations. Amongst the selected citizens, 53.5% had vitamin D deficiency, 31.2% had insufficient vitamin D, and only 15.3% normal vitamin D. CONCLUSION: High rates of vitamin D deficiency in Pakistan despite high levels of sunshine and previous Food Acts asking for food fortification with vitamin D. Public health strategies are needed to address high deficiency rates, including food fortification, i.e. nurture, alongside increasing exposure to sunlight, i.e. nature. This will involve all key stakeholder groups.


Assuntos
Luz Solar , Deficiência de Vitamina D/epidemiologia , Vitamina D/análogos & derivados , Adulto , Idoso , Feminino , Alimentos Fortificados/provisão & distribuição , Humanos , Masculino , Pessoa de Meia-Idade , Paquistão/epidemiologia , Prevalência , Inquéritos e Questionários , Vitamina D/sangue , Adulto Jovem
14.
Leukemia ; 29(9): 1928-38, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25943179

RESUMO

Bone marrow (BM) genetic abnormalities in myelodysplastic syndrome (MDS) have provided important biological and prognostic information; however, frequent BM sampling in older patients has been associated with significant morbidity. Utilizing single-nucleotide polymorphism array (SNP-A) and targeted gene sequencing (TGS) of 24 frequently mutated genes in MDS, we assessed the concordance of genetic abnormalities in BM and peripheral blood (PB) samples concurrently from 201 MDS patients. SNP-A karyotype in BM was abnormal in 108 (54%) and normal in 93 (46%) patients, with 95% (190/201) having an identical PB karyotype. The median copy number (CN) for deletions was significantly lower in BM (CN:1.4 (1-1.9)) than in PB (CN:1.5 (1-1.95), P<0.001). Using TGS, 71% (130/183) patients had BM somatic mutations with 95% (124/130) having identical mutations in PB. The mutant allele burden was lower in PB (median 27% (1-96%)) compared with BM (median 29% (1-100%); P=0.14) with no significant difference in the number, types of mutations or World Health Organization subtype. In all patients with discordant SNP (n=11) and mutation (n=6) profiles between BM and PB, shared abnormalities were always present irrespective of treatment status. Overall, 86% of patients had a clonal aberration with 95% having identical SNP-A karyotype and mutations in PB, thus enabling frequent assessment of response to treatment and disease evolution especially in patients with fibrotic or hypocellular marrows.


Assuntos
Células Sanguíneas/metabolismo , Células da Medula Óssea/metabolismo , Aberrações Cromossômicas , Genômica , Síndromes Mielodisplásicas/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Células Sanguíneas/patologia , Medula Óssea/patologia , Células da Medula Óssea/patologia , Estudos de Coortes , Variações do Número de Cópias de DNA , Análise Mutacional de DNA , Feminino , Estudos de Associação Genética , Humanos , Cariótipo , Masculino , Pessoa de Meia-Idade , Mutação , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/patologia , Polimorfismo de Nucleotídeo Único , Adulto Jovem
15.
Bioinspir Biomim ; 10(3): 036005, 2015 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-25909346

RESUMO

Four species of cacti were chosen for this study: Copiapoa cinerea var. haseltoniana, Ferocactus wislizenii, Mammillaria columbiana subsp. yucatanensis and Parodia mammulosa. It has been reported that dew condenses on the spines of C. cinerea and that it does not on the spines of F. wislizenii, and our preliminary observations of M. columbiana and P. mammulosa revealed a potential for collecting dew water. This study found all four cacti to harvest dew on their stems and spines (albeit rarely on the spines of F. wislizenii). Dew harvesting experiments were carried out in the UK, recording an increase in cacti mass on dewy nights. By applying a ranking relative to a polymethyl methacrylate (Plexiglas) reference plate located nearby, it was found that C. cinerea collected the most airborne moisture followed by M. columbiana, P. mammulosa and F. wislizenii respectively, with mean efficiency ratio with respect to the Plexiglas reference of 3.48 ± 0.5, 2.44 ± 0.06, 1.81 ± 0.14 and 1.27 ± 0.49 on observed dewy nights. A maximum yield of normalized performance of 0.72 ± 0.006 l/m(-2) on one dewy night was recorded for C. cinerea. Removing the spines from M. columbiana was found to significantly decrease its dew harvesting efficiency. The spines of three of the species were found to be hydrophilic in nature, while F. wislizenii was hydrophobic; the stems of all four species were hydrophilic. The results of this study could be translated into designing a biomimetic water collecting device that utilizes cactus spines and their microstructures.


Assuntos
Materiais Biomiméticos/química , Cactaceae/química , Cactaceae/classificação , Caules de Planta/química , Caules de Planta/classificação , Água/química , Adsorção , Teste de Materiais , Especificidade da Espécie
16.
Oncogene ; 34(6): 671-80, 2015 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-24531711

RESUMO

Somatic mutations or deletions of TP53 and PTEN in ductal carcinoma in situ lesions have been implicated in progression to invasive ductal carcinomas. A recent molecular and mutational analysis of breast cancers revealed that inactivation of tumor suppressors, p53 and PTEN, are strongly associated with triple negative breast cancer. In addition, these tumor suppressors have important roles in regulating self-renewal in normal and malignant stem cells. To investigate their role in breast carcinogenesis, we knocked down these genes in human mammary cells and in non-transformed MCF10A cells. p53 and PTEN knockdown synergized to activate pro-inflammatory interleukin-6 (IL6)/Stat3/nuclear factor κB signaling. This resulted in generation of highly metastatic epithelial-to-mesenchymal transition-like cancer stem cells resulting in tumors whose gene expression profile mimicked that found in basal/claudin-low molecular subtype within the triple negative breast tumors. Constitutive activation of this loop in transformed cells was dependent on proteolytic degradation of suppressor of cytokine signaling 3 (SOCS3) resulting in low levels of this protein in basal/claudin-low cell lines and primary tumors. In non-transformed cells, transient activation of the IL6 inflammatory loop induced SOCS3 expression leading to pathway inactivation. In transformed cells, enforced expression of SOCS3 or interfering with IL6 pathway via IL6R blockade inhibited tumor growth and metastasis in mouse xenograft models. Furthermore, circulating tumor cells were significantly reduced in tumor-bearing animals when treated with anti-IL6R antibodies. These studies uncover important connections between inflammation and carcinogenesis and suggest that blocking pro-inflammatory cytokines may be utilized as an attractive strategy to target triple negative breast tumors, which currently lacks molecularly targeted therapies.


Assuntos
Carcinoma Intraductal não Infiltrante/genética , PTEN Fosfo-Hidrolase/genética , Proteínas Supressoras da Sinalização de Citocina/genética , Neoplasias de Mama Triplo Negativas/genética , Proteína Supressora de Tumor p53/genética , Animais , Carcinogênese , Carcinoma Intraductal não Infiltrante/patologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Inflamação/genética , Inflamação/patologia , Interleucina-6/metabolismo , Camundongos , Receptores de Interleucina-6/metabolismo , Proteína 3 Supressora da Sinalização de Citocinas , Proteínas Supressoras da Sinalização de Citocina/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Bioinspir Biomim ; 9(3): 031002, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24646935

RESUMO

Nature has adapted different methods for surviving dry, arid, xeric conditions. It is the focus of this comparative review to pull together the relevant information gleaned from the literature that could be utilized to design moisture harvesting devices informed by biomimetics. Most water harvesting devices in current use are not informed by nature and those that do are usually based on a biomimetic principle that has been based on one species only. This review draws on the published literature to establish a list of species (animals (vertebrates/invertebrates) and plants) whose habitat is in mainly dry or arid regions and that are known to harvest airborne moisture. Key findings have been outlined and review comments and discussion set out. Following this, surface feature convergences have been identified, namely hexagonal microstructures, groove-like and cone-like geometries. This has been coupled with direction of water flow that is driven by surface energy. As far as the authors are aware, this convergent evolution has not been brought together in this manner before. In the future this information could be translated into an engineered device for collecting water from airborne sources.


Assuntos
Plantas/química , Plantas/metabolismo , Absorção Cutânea/fisiologia , Pele/química , Pele/metabolismo , Água/química , Água/metabolismo , Animais , Difusão , Humanos , Modelos Biológicos , Modelos Químicos , Propriedades de Superfície
18.
Cell Death Dis ; 4: e889, 2013 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-24176847

RESUMO

Angiogenesis has a key role in the tumor progression and metastasis; targeting endothelial cell proliferation has emerged as a promising therapeutic strategy for the prevention of cancer. Previous studies have revealed a complex association between the process of angiogenesis and autophagy and its outcome on tumorigenesis. Autophagy, also known as type-II cell death, has been identified as an alternative way of cell killing in apoptotic-resistant cancer cells. However, its involvement in chemoresistance and tumor promotion is also well known. In this study, we used a derivate of natural product magnolol (Ery5), a potent autophagy inducer, to study the association between the autophagy and angiogenesis in both in vitro and in vivo model system. We found that the robust autophagy triggered by Ery5, inhibited angiogenesis and caused cell death independent of the apoptosis in human umbilical cord vein endothelial cells and PC-3 cells. Ery5 induced autophagy effectively inhibited cell proliferation, migration, invasion and tube formation. We further demonstrated that Ery5-mediated autophagy and subsequent inhibition of angiogenesis was reversed when autophagy was inhibited through 3-methyl adenine and knocking down of key autophagy proteins ATG7 and microtubule-associated protein light chain 3. While evaluating the negative regulation of autophagy on angiogenesis, it was interesting to find that angiogenic environment produced by the treatment of VEGF and CoCl2 remarkably downregulated the autophagy and autophagic cell death induced by Ery5. These studies, while disclosing the vital role of autophagy in the regulation of angiogenesis, also suggest that the potent modulators of autophagy can lead to the development of effective therapeutics in apoptosis-resistant cancer.


Assuntos
Autofagia/efeitos dos fármacos , Compostos de Bifenilo/farmacologia , Lignanas/farmacologia , Neovascularização Patológica/metabolismo , Animais , Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Cobalto/farmacologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Proteínas Associadas aos Microtúbulos/metabolismo , Fenóis/farmacologia , Ratos , Fator A de Crescimento do Endotélio Vascular/farmacologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo
19.
Asian Pac J Cancer Prev ; 13(4): 1599-603, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22799374

RESUMO

OBJECTIVES: Since methylenetetrahydrofolate reductase (MTHFR) maintains the balance of circulating folate and methionine and blocks the formation of homocysteine, its regulation in relation to different cancers has extensively been studied in different populations. However, information on Pakistani breast cancer patients is lacking. The MTHFR gene has two most common mutations that are single nucleotide additions which result in change of amino acids C677T to Ala222val and A1298C to Glu429Ala. METHODOLOGY: 110 sporadic breast patients with no prior family history of cancer or any other type of genetic disorders along with 110 normal individuals were screened for mutations in exons 1 to exon 9 using single strand conformational polymorphism, RFLP and sequencing analyzer. RESULTS: The p values for the 677CC, 677CT, and 677TT genotypes were 0.223, 0.006, and 0.077, respectively. Those for the 1298AA, 1298AC, and 1298CC genotypes were 0.555, 0.009, and 0.003, respectively. CONCLUSIONS: We found an overall a significant, weak inverse association between breast cancer risk and the 677TT genotype and an inverse association with the 1298C variant. These results for MTHFR polymorphism might be population specific in sporadic breast cancer affected patients but many other factors need to be excluded before making final conclusions including folate intake, population and disease heterogeneity.


Assuntos
Povo Asiático/genética , Neoplasias da Mama/genética , Genótipo , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Estudos de Casos e Controles , Análise Mutacional de DNA , Éxons , Feminino , Frequência do Gene , Humanos , Paquistão , Polimorfismo de Fragmento de Restrição , Polimorfismo Conformacional de Fita Simples
20.
J Obstet Gynaecol ; 32(5): 475-8, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22663323

RESUMO

This retrospective study of 9,980 women who delivered at the James Paget Hospital, Norfolk, UK, over 5 years, aimed to primarily determine whether the incidence of hyperemesis gravidarum (HG) is higher in the presence of a female fetus. The results showed that more women with HG had a female fetus compared with women without HG. Also found was that heavy ketonuria was more prevalent in women with a female fetus compared with women with a male fetus, and the mean number of admissions per woman was also higher in women with a female fetus compared with women with a male fetus. It can be concluded that women presenting with HG are more likely to have a female fetus and that women with HG and a female fetus tend to a higher level of ketonuria and an increased number of hospital admissions.


Assuntos
Feto , Hiperêmese Gravídica/epidemiologia , Fatores Sexuais , Adulto , Feminino , Idade Gestacional , Humanos , Cetose/epidemiologia , Gravidez , Estudos Retrospectivos
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