Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 64
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Traffic ; 23(1): 81-93, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34761479

RESUMO

SEC24 is mainly involved in cargo sorting during COPII vesicle assembly. There are four SEC24 paralogs (A-D) in vertebrates, which are classified into two subgroups (SEC24A/B and SEC24C/D). Pathological mutations in SEC24D cause osteogenesis imperfecta with craniofacial dysplasia in humans. sec24d mutant fish also recapitulate the phenotypes. Consistent with the skeletal phenotypes, the secretion of collagen was severely defective in mutant fish, emphasizing the importance of SEC24D in collagen secretion. However, SEC24D patient-derived fibroblasts show only a mild secretion phenotype, suggesting tissue-specificity in the secretion process. Using Sec24d KO mice and cultured cells, we show that SEC24A and SEC24B also contribute to endoplasmic reticulum (ER) export of procollagen. In contrast, fibronectin 1 requires either SEC24C or SEC24D for ER export. On the basis of our results, we propose that procollagen interacts with multiple SEC24 paralogs for efficient export from the ER, and that this is the basis for tissue-specific phenotypes resulting from SEC24 paralog deficiency.


Assuntos
Pró-Colágeno , Proteínas de Transporte Vesicular , Animais , Vesículas Revestidas pelo Complexo de Proteína do Envoltório/metabolismo , Retículo Endoplasmático/metabolismo , Camundongos , Fenótipo , Pró-Colágeno/genética , Pró-Colágeno/metabolismo , Transporte Proteico , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismo
2.
Environ Res ; 247: 118284, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38253196

RESUMO

Ambient fine particulate matter (PM2.5) is a leading environmental risk factor globally, and over half of the associated disease burden are caused by cardiovascular disease. Numerous randomized controlled trials (RCT) have investigated the short-term cardiovascular benefits of indoor air purifiers (IAPs), but major knowledge gaps remain on their longer-term benefits. In this 1-year, randomized, double-blinded, parallel controlled trial of 47 elderly (ntrue-purification = 24; nsham-purification = 23) aged ≥70 years, true-purification reduced household PM2.5 levels by 28% and maintained lower exposure throughout the year compared to the sham-purification group. After 12 months of intervention, a significant reduction of diastolic blood pressure was found in the true-purification versus sham-purification group (-4.62 [95% CI: -7.28, -1.96] mmHg) compared to baseline measurement prior to the intervention, whereas systolic blood pressure showed directionally consistent but statistically non-significant effect (-2.49 [95% CI: -9.25, 4.28] mmHg). Qualitatively similar patterns of associations were observed for pulse pressure (-2.30 [95% CI: -6.57, 1.96] mmHg) and carotid intima-media thickness (-10.0% [95% CI: -24.8%, 4.7%]), but these were not statistically significant. Overall, we found suggestive evidence of cardiovascular benefits of long-term IAPs use, particularly on diastolic blood pressure. Evidence on other longer-term cardiovascular traits is less clear. Further trials with larger sample sizes and long-term follow-up are needed across diverse populations to evaluate the cardiovascular benefits of IAPs.


Assuntos
Filtros de Ar , Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Poluição do Ar , Doenças Cardiovasculares , Sistema Cardiovascular , Idoso , Humanos , Poluição do Ar em Ambientes Fechados/prevenção & controle , Poluição do Ar em Ambientes Fechados/análise , Hong Kong , Material Particulado/análise , Doenças Cardiovasculares/prevenção & controle , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Ensaios Clínicos Controlados Aleatórios como Assunto
3.
J Cell Mol Med ; 24(2): 1993-2003, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31856355

RESUMO

These days, cancer can still not be effectively cured because cancer cells readily develop resistance to anticancer drugs. Therefore, an effective combination of drugs with different mechanisms to prevent drug resistance has become a very important issue. Furthermore, the BH3-only protein BNIP3 is involved in both apoptotic and autophagic cell death. In this study, lung cancer cells were treated with a chemotherapy drug alone or in combination to identify the role of BNIP3 and autophagy in combination chemotherapy for treating cancer. Our data revealed that various combinational treatments of two drugs could increase cancer cell death and cisplatin in combination with rapamycin or LBH589, which triggered the cell cycle arrest at the S phase. Cells with autophagosome and pEGFP-LC3 puncta increased when treated with drugs. To confirm the role of autophagy, cancer cells were pre-treated with the autophagy inhibitor 3-methyladenine (3-MA). 3-MA sensitized cancer cells to chemotherapy drug treatments. These results suggest that autophagy may be responsible for cell survival in combination chemotherapy for lung cancer. Moreover, BNIP3 was induced and localized in mitochondria when cells were treated with drugs. The transfection of a dominant negative transmembrane deletion construct of BNIP3 (BNIP3ΔTM) and treatment of a reactive oxygen species (ROS) inhibitor suppressed chemo drug-induced cell death. These results indicate that BNIP3 and ROS may be involved in combination chemo drug-induced cell death. However, chemo drug-induced autophagy may protect cancer cells from drug cytotoxicity. As a result, inhibiting autophagy may improve the effects of combination chemotherapy when treating lung cancer.


Assuntos
Autofagia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Proteínas de Membrana/metabolismo , Platina/uso terapêutico , Proteínas Proto-Oncogênicas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Células A549 , Adenina/análogos & derivados , Adenina/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Autofagia/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Quimioterapia Combinada , Humanos , Neoplasias Pulmonares/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Membranas Mitocondriais/efeitos dos fármacos , Membranas Mitocondriais/metabolismo , Modelos Biológicos , Platina/farmacologia , Transporte Proteico/efeitos dos fármacos
4.
Environ Sci Technol ; 54(11): 6869-6877, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32363866

RESUMO

Few studies have investigated the short-term effect of personal temperature exposure on blood oxygen saturation (SpO2). We conducted this longitudinal panel study with real-time monitoring of SpO2 and environmental exposure for 3 continuous days for 20 patients with chronic obstructive pulmonary disease (COPD) and 20 healthy volunteers in Hong Kong, to explore the time course (from minutes to hours) of change in SpO2 in response to temperature in elderly people. We employed a generalized additive mixed model to evaluate the acute effects of personal temperature exposure on changes in SpO2 and risk of oxygen desaturation while adjusting for seasonality, environmental co-exposures, and personal characteristics. We observed a concurrent decline in SpO2 by 0.27% (95% confidence interval [CI]: 0.22-0.32%) and an increase in the risk of oxygen desaturation by an OR of 1.14 (95% CI, 1.10-1.18) associated with a 1 °C increase in personal temperature, and the association lasted over several hours. Results showed that the decline in SpO2 in elderly people was associated with an increase in personal temperature exposure within minutes to hours, particularly in women and male patients with COPD. Temperature-induced oxygen desaturation may play a pivotal role in COPD exacerbation.


Assuntos
Oximetria , Doença Pulmonar Obstrutiva Crônica , Idoso , Feminino , Hong Kong , Humanos , Masculino , Oxigênio , Temperatura
5.
BMC Ophthalmol ; 19(1): 28, 2019 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-30674274

RESUMO

PURPOSE: A recent meta-analysis revealed PAX6 as a risk gene for myopia. There is a link between PAX6 and HOXA9. Furthermore, HOXA9 has been reported to activate TGF-ß that is a risk factor for myopia. We speculate HOXA9 may participate in myopia development. METHODS: The Singapore GUSTO birth cohort provides data on children's cycloplegic refraction measured at age of 3 years and their methylation profile based on the umbilical cord DNA. The HOXA9 expression levels were measured in the eyes of mono-ocular form deprivation myopia in mice. The plasmid with the mouse HOXA9 cDNA was constructed and then transfected to mouse primary retinal pigment epithelial (RPE) cells. The expression levels of myopia-related genes and cell proliferation were measured in the HOXA9-overexpressed RPE cells. RESULTS: A total of 519 children had data on methylation profile and cycloplegic refraction. The mean spherical equivalent refraction (SE) was 0.90D. Among 8 SE outliers (worse than -2D), 7 children had HOXA9 hypomethylation. The HOXA9 levels in the retina of myopic eyes was 2.65-fold (p = 0.029; paired t-test) higher than the uncovered fellow eyes. When HOXA9 was over-expressed in the RPE cells, TGF-ß, MMP2, FGF2 and IGF1R expression levels were dose-dependently increased by HOXA9. However, over-expression of HOXA9 had no significant influence on IGF1 or HGF expression. In addition, HOXA9 also increased RPE proliferation. CONCLUSION: Based on the human, animal and cellular data, the transcription factor HOXA9 may promote the expression of pro-myopia genes and RPE proliferation, which eventually contribute to myopia development.


Assuntos
Proteínas de Homeodomínio/fisiologia , Miopia/metabolismo , Animais , Comprimento Axial do Olho/patologia , Proliferação de Células , Células Cultivadas , Pré-Escolar , Modelos Animais de Doenças , Células Epiteliais/metabolismo , Feminino , Regulação da Expressão Gênica , Proteínas de Homeodomínio/metabolismo , Humanos , Masculino , Camundongos , MicroRNAs/fisiologia , Miopia/genética , Miopia/patologia , Epitélio Pigmentado da Retina/metabolismo
6.
Physiol Genomics ; 50(9): 669-679, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29932826

RESUMO

Phosphorylation and lysine (K)-acetylation are dynamic posttranslational modifications of proteins. Previous proteomic studies have identified over 170,000 phosphorylation sites and 15,000 K-acetylation sites in mammals. We recently reported that the inner medullary collecting duct (IMCD), which functions in the regulation of water-reabsorption, via the actions of vasopressin, expresses many of the enzymes that can modulated K-acetylation. The purpose of this study was to determine the K-acetylated or phosphorylated proteins expressed in IMCD cells. Second we questioned whether vasopressin V2 receptor activation significantly affects the IMCD acetylome or phosphoproteome? K-acetylated or serine-, threonine-, or tyrosine-phosphorylated peptides were identified from native rat IMCDs by proteomic analysis with four different enzymes (trypsin, chymotrypsin, ASP-N, or Glu-C) to generate a high-resolution proteome. K-acetylation was identified in 431 unique proteins, and 64% of the K-acetylated sites were novel. The acetylated proteins were expressed in all compartments of the cell and were enriched in pathways including glycolysis and vasopressin-regulated water reabsorption. In the vasopressin-regulated water reabsorption pathway, eight proteins were acetylated, including the novel identification of the basolateral water channel, AQP3, acetylated at K282; 215 proteins were phosphorylated in this IMCD cohort, including AQP2 peptides that were phosphorylated at four serines: 256, 261, 264, and 269. Acute dDAVP did not significantly affect the IMCD acetylome; however, it did significantly affect previously known vasopressin-regulated phosphorylation sites. In conclusion, presence of K-acetylated proteins involved in metabolism, ion, and water transport in the IMCD points to multiple roles of K-acetylation beyond its canonical role in transcriptional regulation.


Assuntos
Túbulos Renais Coletores/metabolismo , Lisina/metabolismo , Fosfoproteínas/metabolismo , Proteoma/metabolismo , Proteômica/métodos , Acetilação/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Gluconeogênese/efeitos dos fármacos , Glicólise/efeitos dos fármacos , Masculino , Fosfopeptídeos/química , Fosfoproteínas/química , Proteoma/química , Ratos Sprague-Dawley , Vasopressinas/farmacologia
7.
Chemistry ; 23(11): 2571-2582, 2017 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-27798822

RESUMO

Engineered bacterial cytochrome P450s are noted for their ability in the oxidation of inert small alkanes. Cytochrome P450 BM3 L188P A328F (BM3 PF) and A74E L188P A328F (BM3 EPF) variants are able to efficiently oxidize n-butane to 2-butanol. Esterification of the 2-butanol derived from this reaction mediated by the aforementioned two mutants gives diastereomeric excesses (de) of -56±1 and -52±1 %, respectively, with the preference for the oxidation occurring at the C-HS bond. When tailored (2R,3R)- and (2S,3S)-[2-2 H1 ,3-2 H1 ]butane probes are employed as substrates for both variants, the obtained de values from (2R,3R)-[2-2 H1 ,3-2 H1 ]butane are -93 and -92 % for BM3 PF and EPF, respectively; whereas the obtained de values from (2S,3S)-[2-2 H1 ,3-2 H1 ]butane are 52 and 56 % in the BM3 PF and EPF systems, respectively. The kinetic isotope effects (KIEs) for the oxidation of (2R,3R)-[2-2 H1 ,3-2 H1 ]butane are 7.3 and 7.8 in BM3 PF and EPF, respectively; whereas KIEs for (2S,3S)-[2-2 H1 ,3-2 H1 ]butanes are 18 and 25 in BM3 PF and EPF, respectively. The discrepancy in KIEs obtained from the two substrates supports the two-state reactivity (TSR) that is proposed for alkane oxidation in cytochrome P450 systems. Moreover, for the first time, experimental evidence for tunneling in the oxidation mediated by P450 is given through the oxidation of the C-HR bond in (2S,3S)-[2-2 H1 ,3-2 H1 ]butane.


Assuntos
Proteínas de Bactérias/metabolismo , Butanos/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Bactérias/enzimologia , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Biocatálise , Butanos/química , Butanóis/análise , Butanóis/química , Butanóis/metabolismo , Domínio Catalítico , Sistema Enzimático do Citocromo P-450/química , Sistema Enzimático do Citocromo P-450/genética , Escherichia coli/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Hidroxilação , Cinética , Mutagênese Sítio-Dirigida , Oxirredução , Estereoisomerismo , Especificidade por Substrato , Termodinâmica
8.
Am J Med Genet A ; 173(11): 2893-2897, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28985029

RESUMO

Craniosynostosis presents either as a nonsyndromic congenital anomaly or as a finding in nearly 200 genetic syndromes. Our previous genome-wide association study of sagittal nonsyndromic craniosynostosis identified associations with variants downstream from BMP2 and intronic in BBS9. Because no coding variants in BMP2 were identified, we hypothesized that conserved non-coding regulatory elements may alter BMP2 expression. In order to identify and characterize noncoding regulatory elements near BMP2, two conserved noncoding regions near the associated region on chromosome 20 were tested for regulatory activity with a Renilla luciferase assay. For a 711 base pair noncoding fragment encompassing the most strongly associated variant, rs1884302, the luciferase assay showed that the risk allele (C) of rs1884302 drives higher expression of the reporter than the common allele (T). When this same DNA fragment was tested in zebrafish transgenesis studies, a strikingly different expression pattern of the green fluorescent reporter was observed depending on whether the transgenic fish had the risk (C) or the common (T) allele at rs1884302. The in vitro results suggest that altered BMP2 regulatory function at rs1884302 may contribute to the etiology of sagittal nonsyndromic craniosynostosis. The in vivo results indicate that differences in regulatory activity depend on the presence of a C or T allele at rs1884302.


Assuntos
Proteína Morfogenética Óssea 2/genética , Anormalidades Congênitas/genética , Craniossinostoses/genética , Predisposição Genética para Doença , Alelos , Animais , Animais Geneticamente Modificados/genética , Anormalidades Congênitas/fisiopatologia , Sequência Conservada , Regulação da Expressão Gênica/genética , Estudo de Associação Genômica Ampla , Humanos , Polimorfismo de Nucleotídeo Único , Sequências Reguladoras de Ácido Nucleico/genética , Peixe-Zebra/genética
9.
Anim Biotechnol ; 28(3): 174-181, 2017 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-27834588

RESUMO

This study was conducted to confirm that 1-site and 4-site ppU6-GGTA1-gRNA CRISPR vectors together with the pCX-Flag2-NLS1-Cas9-NLS2 plasmid can both generate KO pigs by direct pronuclear microinjection. In total, 41 and 53 fertilized eggs were microinjected on 1-site and 4-site strategies, respectively. The 1-site construction generated a litter of 8 piglets, and 2 were mono-allelic mutant (mMt). The injection of 4-site constructions resulted in one biallelic mutant (bMt) and one mMt piglet in a litter of 7. Those 3 mMt pigs had a 4 bp deletion, 5 bp insertion, or 7 bp insertion at site I, and the bMt pig had 5 types of mutations at cleavage sites I and III. The expression of alpha-Gal on the bMt peripheral blood mononuclear cells (PBMCs) was reduced, and survival rate of bMt PBMCs was maintained as indicated by results of cultivation with sera of humans or Formosan Macaques. We concluded that mutant pigs could be generated by direct pronuclear microinjection of ppU6-GGTA1-gRNA CRISPR vectors with the pCX-Flag2-NLS1-Cas9-NLS2 plasmid and that the 4-site strategy has a better mutant efficiency. Porcine U6 promoter was firstly used to express KO vectors and effectively generate mutant pigs, worthily to adopt for future KO studies.


Assuntos
Sistemas CRISPR-Cas/genética , Galactosiltransferases/genética , Técnicas de Inativação de Genes/métodos , Plasmídeos/genética , Animais , Feminino , Técnicas de Transferência de Genes , Leucócitos Mononucleares/metabolismo , Masculino , Microinjeções , Mutação/genética , Suínos
10.
Indian J Crit Care Med ; 21(1): 11-16, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28197045

RESUMO

CONTEXT: Regional citrate anticoagulation for continuous renal replacement therapy is associated with a longer filter-life, less bleeding events and improved mortality. Problems associated with using Prismocitrate 10/2 solution in continuous renal replacement therapy, include hypomagnesemia, hypophosphatemia and the need for additional bicarbonate infusion. AIMS: This study uses the new Prismocitrate 18/0 solution for improved buffer balance and Phoxilium solution for a more favourable electrolyte profile. SETTINGS AND DESIGN: A retrospective analysis of patients who underwent continuous venovenous hemofiltration (CVVH) using Prismocitrate 18/0 and Phoxilium in our 21-bed ICU was conducted from March to July 2014. METHODS AND MATERIAL: Continuous venovenous hemofiltration (CVVH) was performed at fixed rate by using Prismocitrate 18/0 predilution at 1250 ml/hour, a blood flow rate of 110 ml/min and post-replacement with Phoxilium at 1250 ml/hr. CVVH was run for 72 h or until filter clotting, transportation, or achievement of the clinical target. STATISTICAL ANALYSIS USED: The results were displayed as the median with the interquartile range (IQR). The trend in pH, electrolytes, and base excess are shown using a standard box plot. All analyses were performed by the Statistical Package for Social Science for Windows, version 17 (SPSS, Chicago, IL, USA). RESULTS: Forty-five CVVH episodes were analysed. The median circuit lifetime was 44 h (interquartile range, IQR 29-55). Metabolic alkalosis, hypophosphatemia and hypomagnesemia occurred in 8.3%, 3.5% and 40.2% of the blood samples, respectively. No patient developed hypokalemia or citrate toxicity. CONCLUSIONS: This new CVVH regime is safe and easy to administer for critically ill patients.

11.
J Am Soc Nephrol ; 25(7): 1486-95, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24511119

RESUMO

Galectin-1, a ß-galactoside-binding lectin, is involved in many physiologic and pathologic processes, including cell adhesion, differentiation, angiogenesis, and tumor progression. However, the role of galectin-1 in kidney cancer remains elusive. This study evaluated the role of galectin-1 in the progression and clinical prognosis of renal cell carcinoma. We found significant overexpression of galectin-1 in both kidney cancer cell lines and metastatic tissue specimens from patients with renal cell carcinoma. Knockdown of galectin-1 gene expression in renal cancer cell lines reduced cell invasion, clonogenic ability, and epithelial-mesenchymal transition in vitro; reduced tumor outgrowth in vivo; and inhibited the angiogenesis-inducing activity of these cells in vitro and in vivo. Galectin-1 knockdown decreased CXCR4 expression levels in kidney cancer cells, and restoration of CXCR4 expression in galectin-1-silenced cells rescued cell motility and clonogenic ability. Additional studies suggested that galectin-1 induced CXCR4 expression through activation of nuclear factor-κB (NF-κB). Analysis of patient specimens confirmed the clinical significance and positive correlation between galectin-1 and CXCR4 expression levels and revealed concomitant overexpression of galectin-1 and CXCR4 associated adversely with overall and disease-free survival. Our findings suggest that galectin-1 promotes tumor progression through upregulation of CXCR4 via NF-κB. The coordinated upregulation of galectin-1 and CXCR4 may be a novel prognostic factor for survival in patients with renal cell carcinoma and the galectin-1-CXCR4 axis may serve as a therapeutic target in this disease.


Assuntos
Carcinoma de Células Renais/mortalidade , Carcinoma de Células Renais/patologia , Galectina 1/fisiologia , Neoplasias Renais/mortalidade , Neoplasias Renais/patologia , Receptores CXCR4/fisiologia , Regulação para Cima , Progressão da Doença , Humanos , Prognóstico , Taxa de Sobrevida , Células Tumorais Cultivadas
12.
Carcinogenesis ; 35(4): 769-75, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24233839

RESUMO

Hepatocellular carcinoma (HCC) is one of the most common fatal cancers worldwide. Other than the sorafenib treatment, no effective systemic therapy has been available thus far. Most targets in molecularly targeted therapy for cancer are receptor tyrosine kinases (RTKs). Therefore, identifying activated RTKs in HCC is critical for developing new molecularly targeted therapies. Using a phospho-RTK array, we found that Axl is one of the most frequently activated RTKs in liver cancer cell lines. The knockdown of Axl by RNA interference significantly reduced cell migration and invasion in the HCC cell lines HA22T and Mahlavu. Stimulation of HCC cell lines by Axl ligand growth arrest-specific 6 (Gas6) enhanced cell migration and invasion. The Gas6/Axl pathway enhanced the expression of the epithelial-mesenchymal transition-inducing transcription factor Slug, which is essential for the invasion-promoting activity of Axl. Treating HCC cells with the Axl inhibitor bosutinib suppressed Slug expression and decreased the invasiveness of HCC cell lines. These findings indicate that Gas6/Axl regulates tumor invasion through the transcriptional activation of Slug.


Assuntos
Carcinoma Hepatocelular/patologia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Neoplasias Hepáticas/patologia , Invasividade Neoplásica , Fatores de Transcrição/genética , Ativação Transcricional , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Primers do DNA , Técnicas de Silenciamento de Genes , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Neoplasias Hepáticas/metabolismo , Interferência de RNA , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Transcrição da Família Snail
13.
Sci Total Environ ; 912: 169156, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38065490

RESUMO

To investigate the characteristics of oxygenated volatile organic compounds (OVOCs) and their potential contribution to ozone (O3) generation, we conducted 3-h high-resolution observations during the summertime of 2022 and the wintertime of 2021. This study focused on a total of 28 OVOCs in five different chemical classes, which were encompassed at two representative sites in Hong Kong, including a roadside and an urban area. During the summertime, the total concentrations of quantified OVOCs (∑OVOCs) were 45 ± 12 and 63 ± 20 µg m-3 at the roadside and urban sites, respectively, whereas the ∑OVOCs decreased by 31 ± 11 % and 38 ± 13 %, respectively, during the wintertime. Among the classes of OVOCs, carbonyls and alcohols were the two predominant at both sites, with relatively higher concentration levels of acetone, methanol, butanaldehyde, and acrolein. The sources of OVOCs have significant spatial and temporal characteristics. Spatially, OVOCs were predominately attributed to primary emission and background at the roadside site, whereas they were a combination of primary emission, secondary formation, and background at the urban site. Temporally, background sources dominated the summertime OVOCs, while the contribution of primary emissions increased for the wintertime OVOCs. The O3 formation potential (OFP) for the OVOCs was calculated. The OFPs were 67 ± 16 and 119 ± 31 µg m-3 at the roadside and urban sites during the summertime, whereas the winter OFPs declined 30 % at the roadside and 38 % at the urban site. The background sources of carbonyls and alcohols at the roadside and of carbonyls and acrylates in the urban area were the major contributors to the summer OFP. Controlling the OVOC sources from local non-combustion sources such as gasoline-fuel evaporation and volatile chemical-containing products could lead to a reduction of OVOCs in the background and subsequently mitigate the OFP. This is beneficial for local O3 reduction in Hong Kong and surrounding regions.

14.
Chemosphere ; 357: 141975, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38615960

RESUMO

This study investigated the determinants of personal exposures (PE) to coarse (PM2.5-10) and fine particulate matter (PM2.5) for elderly communities in Hong Kong. The mean PE PM2.5 and PM2.5-10 were 23.6 ± 10.8 and 13.5 ± 22.1 µg/m3, respectively during the sampling period. Approximately 76% of study subjects presented statistically significant differences between PE and ambient origin for PM2.5 compared to approximately 56% for PM2.5-10, possibly due to the coarse-size particles being more influenced by similar sources (road dust and construction dust emissions) compared to the PM2.5 particles. Individual PE to ambient (P/A) ratios for PM2.5 all exceeded unity (≥1), suggesting the dominant influences of non-ambient particles contributed towards total PE values. There were about 80% individual P/A ratios (≤1) for PM2.5-10, implying possible effective infiltration prevention of larger size particulate matter particles leading to dominant influences from the outdoor sources. The higher concentration of NO3- and SO42- in PM2.5-10 compared to PM2.5 suggests possible heterogeneous reactions of alkaline minerals leading to the formation of NO3- and SO42- in PM2.5-10 particles. The PE and ambient OC/EC ratios in PM2.5 (8.8 ± 3.3 and 10.4 ± 22.4, respectively) and in PM2.5-10 (6.0 ± 1.9 and 3.0 ± 1.1, respectively) suggest possible secondary formed OC from surrounding rural areas. Heterogeneous distributions (COD >0.2) between the PE and ambient concentrations were found for both the PM2.5 and PM2.5-10 samples. The calibration coefficient as the association between personal and surrogate exposure measure of PE to PM2.5 (0.84) was higher than PM2.5-10 (0.52). The findings further confirm that local sources were the dominant contributor to the coarse particles and these coefficients can potentially be used to estimate different PE to PM2.5 and PM2.5-10 conditions. A comprehensive understanding of the PE to determinants in coarse particles is essential to further reduce potential exposure misclassification.


Assuntos
Poluição do Ar , Exposição por Inalação , Material Particulado , Humanos , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Masculino , Feminino , Material Particulado/análise , Exposição por Inalação/estatística & dados numéricos , Poluição do Ar/estatística & dados numéricos , Hong Kong , Tamanho da Partícula , Monitoramento Ambiental , Nitratos/análise , Sulfatos/análise
15.
Chemistry ; 19(41): 13680-91, 2013 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-24092541

RESUMO

We demonstrate herein that wild-type cytochrome P450 BM3 can recognize non-natural substrates, such as fluorinated C12 -C15 chain-length fatty acids, and show better catalysis for their efficient conversion. Although the binding affinities for fluorinated substrates in the P450 BM3 pocket are marginally lower than those for non-fluorinated substrates, spin-shift measurements suggest that fluoro substituents at the ω-position can facilitate rearrangement of the dynamic structure of the bulk-water network within the hydrophobic pocket through a micro desolvation process to expel the water ligand of the heme iron that is present in the resting state. A lowering of the Michaelis-Menten constant (Km ), however, indicates that fluorinated fatty acids are indeed better substrates compared with their non-fluorinated counterparts. An enhancement of the turnover frequencies (kcat ) for electron transfer from NADPH to the heme iron and for CH bond oxidation by compound I (Cpd I) to yield the product suggests that the activation energies associated with going from the enzyme-substrate (ES state) to the corresponding transition state (ES(≠) state) are significantly lowered for both steps in the case of the fluorinated substrates. Delicate control of the regioselectivity by the fluorinated terminal methyl groups of the C12 -C15 fatty acids has been noted. Despite the fact that residues Arg47/Tyr51/Ser72 exert significant control over the hydroxylation of the subterminal carbon atoms toward the hydrocarbon tail, the fluorine substituent(s) at the ω-position affects the regioselective hydroxylation. For substrate hydroxylation, we have found that fluorinated lauric acids probably give a better structural fit for the heme pocket than fluorinated pentadecanoic acid, even though pentadecanoic acid is by far the best substrate among the reported fatty acids. Interestingly, 12-fluorododecanoic acid, with only one fluorine atom at the terminal methyl group, exhibits a comparable turnover frequency to that of pentadecanoic acid. Thus, fluorination of the terminal methyl group introduces additional interactions of the substrate within the hydrophobic pocket, which influence the electron transfers for both dioxygen activation and the controlled oxidation of aliphatics mediated by high-valent oxoferryl species.


Assuntos
Ácidos Graxos/química , Ácidos Láuricos/química , Sistema Enzimático do Citocromo P-450 , Fluorocarbonos , Halogenação , Ligação de Hidrogênio , Hidroxilação , Oxirredução
16.
Front Allergy ; 4: 1290021, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38125294

RESUMO

Background: Urticaria (defined as the presence of hives, angioedema, or both) can be caused by a variety of etiologies ranging from more common conditions such as chronic spontaneous urticaria (CSU) to rarer conditions such as hereditary angioedema (HAE). Specialist referral may be necessary in cases of severe urticaria or HAE, but access to specialist services remains limited in certain regions, such as the Greater Bay Area (GBA) of China. To address this, the Hong Kong-Macau Severe Hives and Angioedema Referral Pathway (SHARP) was initiated by the Hong Kong Institute of Allergy and Macau Society of Dermatology to promote multidisciplinary collaboration and regional exchange of expertise in the diagnosis and management of severe urticaria. Methods: A nominated task force of dermatologists and immunologists who manage patients with severe urticaria formulated the consensus statements (CS) using the Delphi method. The consensus was defined a priori as an agreement of ≥80%. Results: A total of 24 CS were formulated, including four statements on classifications and definitions, seven statements on diagnosis, and 13 statements on management and referral. The definitions for acute/chronic urticaria and severe CSU were stated. Unnecessary investigations and inappropriate medications were discouraged. The characteristics and recommended approach to suspected bradykinergic angioedema were specified. Stepwise treatment options using second-generation antihistamines, omalizumab, or cyclosporin for patients with CSU were addressed, and the importance of access to HAE-specific medications was emphasized. Furthermore, an integrated referral pathway for patients with severe hives and angioedema was constructed. Conclusion: The SHARP provides guidance for the management and specialist referral of patients with severe hives and angioedema in Hong Kong and Macau.

17.
Biomedicines ; 11(2)2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36830824

RESUMO

We previously reported anti-miR-328 therapy for dry eye disease (DED). Since decreased mucin secretion is a risk factor for DED, we aimed to explore whether anti-miR-328 affects mucin expression and goblet cells. MiR-328 was increased in goblet cells when they were under desiccating stress or treated with benzalkonium chloride (BAC), both of which are risk factors for DED. Based on bioinformatics tool results, miR-328 was predicted to directly target the transcription factor CREB1 that has been known to promote the expression of mucin5AC. The inhibitory effect of miR-328 on CREB1 was confirmed by the transfection assay. A miR-328 binding site on the CREB1 gene was confirmed by the luciferase assay. Furthermore, anti-miR-328 increased CREB1 and mucin5AC in cultured goblet cells according to qPCR, Western blot, and IF staining experiments. Anti-miR-328 increased mucin5AC secretion from the cultured goblet cells based on an ELISA assay for the cultured medium. Finally, impression cytology data revealed anti-miR-328 increased conjunctival goblet cells in the DED rabbits induced by BAC. In conclusion, anti-miR-328 increases CREB1 expression leading to an increase in mucin5AC production and secretion. Furthermore, anti-miR-328 also increases conjunctival goblet cells. These results warrant the further development of anti-miR-328 therapy for DED.

18.
Cell Immunol ; 273(1): 79-84, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22169226

RESUMO

Ultraviolet B (UVB) radiation may cause the inflammation of retinal pigment epithelium (RPE) cells and play a role in development of age-related macular degeneration (AMD). The activation of the complement factor B (CFB) gene has been shown to be involved in formation of AMD. Here our results revealed that UVB induces IL-6/STAT3 signaling activation and the UVB-induced STAT3 is able to regulate the CFB expression in ARPE-19 cells. Tannic acid (TA) is a kind of water-soluble polyphenol and may have anti-inflammation effects. We also found that TA attenuates the UVB-induced IL-6 protein production, the STAT3 phosphorylation and the CFB expression. Taken together, these findings suggest UVB-induced inflammation of RPE can be mediated through the IL-6/STAT3/CFB pathway, and TA has a protected effect via the inhibition to the inflammatory response.


Assuntos
Fator B do Complemento/imunologia , Interleucina-6/imunologia , Epitélio Pigmentado da Retina/efeitos dos fármacos , Epitélio Pigmentado da Retina/efeitos da radiação , Fator de Transcrição STAT3/imunologia , Taninos/farmacologia , Raios Ultravioleta/efeitos adversos , Linhagem Celular , Fator B do Complemento/genética , Humanos , Immunoblotting , Interleucina-6/genética , Degeneração Macular/etiologia , Degeneração Macular/imunologia , RNA/química , RNA/genética , Reação em Cadeia da Polimerase em Tempo Real , Epitélio Pigmentado da Retina/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais
19.
Mol Vis ; 18: 471-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22393273

RESUMO

PURPOSE: Fibroblast growth factor-2 (FGF2) has been implied in the development of myopia according to previous studies investigating FGF2 in the sclera and retinal pigment epithelium. This study measured retinal FGF2 gene expression in an animal model and also tested for the association between single nucleotide polymorphisms (SNPs) in FGF2 and high myopia. METHODS: The guinea pigs were assigned to 2 groups: form deprivation myopia (FDM) for two weeks and normal control (free of form deprivation). Biometric measurement was performed and FGF2 expression levels were compared among the FDM eyes, the fellow eyes of the FDM group and the normal eyes in retina. We also enrolled 1,064 cases (≤-6.0 D) and 1,001 controls (≥-1.5 D) from a Chinese population residing in Taiwan. Six tagging SNPs were genotyped to test for an association between genotypes and high myopia. RESULTS: The FDM eyes had the most prominent changes of refraction and axial length. Compared with the mRNA levels of FGF2 in the normal eyes, the FDM eyes had the highest levels of mRNA (p=0.0004) followed by the fellow eyes (p=0.002). The FDM and normal eyes became more myopic compared with the fellow eyes, but the fellow eyes became more hyperopic (p=0.004) in the end of the experiment which may be due to its relatively short axial length when compared with normal eyes (p=0.05). The SNP genotypes were all in Hardy-Weinberg equilibrium. However, none of the SNPs were significantly associated with high myopia (all p values >0.1). CONCLUSIONS: We identified a significant change of FGF2 expression in the FDM eyes but FGF2 genetic variants are unlikely to influence susceptibility to myopia. There may be a systemic effect to influence gene expression and refraction on the fellow eyes, which may perturb emmetropization in the fellow eyes. Our data also suggest using normal eyes rather than the fellow eyes as the control eyes when study the form deprivation myopia.


Assuntos
Fator 2 de Crescimento de Fibroblastos/genética , Miopia/genética , Polimorfismo de Nucleotídeo Único/genética , RNA Mensageiro/biossíntese , Adolescente , Adulto , Animais , Comprimento Axial do Olho/patologia , Biometria , Estudos de Casos e Controles , Modelos Animais de Doenças , Feminino , Expressão Gênica , Genótipo , Cobaias , Humanos , Masculino , Pessoa de Meia-Idade , Miopia/patologia , Refração Ocular , Privação Sensorial
20.
Environ Monit Assess ; 184(8): 4725-35, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21887478

RESUMO

A semi-continuous water-quality monitoring system was installed in Yunlin Offshore Industrial Park (YOIP), the largest industrial park in Taiwan, in 2007 to provide real-time water-quality information such as pH, water depth, dissolved oxygen, temperature, turbidity, conductivity, and chlorophyll. To interpret the large quantities of high-frequency data generated by this system, information theory was applied for data analysis and extraction of useful information for further coastal water-quality management. Information theory is a branch of applied mathematics that involves the quantification of information. Shannon entropy is a key measure of information that was calculated in this study to reveal the inherent uncertainty of water-quality information. The applicability of Shannon entropy for signaling possible coastal pollution events in the YOIP was explored and results showed that it provides new insight into the inherent uncertainty or randomness of the original data. Specially, when Shannon entropy was high, multiple instable readings were observed for turbidity and salinity. This indicates that Shannon entropy may be a useful new tool for exploratory data analysis. It can be used as a supplementary indicator along with the original environmental data to signify some episodes of water-quality degradation.


Assuntos
Monitoramento Ambiental/métodos , Poluentes da Água/análise , Poluição da Água/estatística & dados numéricos , Conservação dos Recursos Naturais , Indústrias/estatística & dados numéricos , Qualidade da Água/normas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA