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1.
Nat Commun ; 14(1): 3243, 2023 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-37277343

RESUMO

Insertions are one of the major types of structural variations and are defined as the addition of 50 nucleotides or more into a DNA sequence. Several methods exist to detect insertions from next-generation sequencing short read data, but they generally have low sensitivity. Our contribution is two-fold. First, we introduce INSurVeyor, a fast, sensitive and precise method that detects insertions from next-generation sequencing paired-end data. Using publicly available benchmark datasets (both human and non-human), we show that INSurVeyor is not only more sensitive than any individual caller we tested, but also more sensitive than all of them combined. Furthermore, for most types of insertions, INSurVeyor is almost as sensitive as long reads callers. Second, we provide state-of-the-art catalogues of insertions for 1047 Arabidopsis Thaliana genomes from the 1001 Genomes Project and 3202 human genomes from the 1000 Genomes Project, both generated with INSurVeyor. We show that they are more complete and precise than existing resources, and important insertions are missed by existing methods.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de DNA/métodos
2.
Artigo em Inglês | MEDLINE | ID: mdl-35805362

RESUMO

BACKGROUND: With an increasing aging population and heavy medical burden, euthanasia has become a controversial topic in Hong Kong (HK) in recent years. Medical students are future medical professionals who may face novel and evolving ethical dilemmas. Hence, their views on euthanasia are crucial. OBJECTIVE: To examine the attitudes of medical students towards euthanasia in HK and identify the factors associated with their attitude towards euthanasia. METHODS: A questionnaire-based cross-sectional study among medical students in HK was conducted. The online anonymous questionnaires were distributed to all six years of students studying medicine at the Chinese University of Hong Kong (CUHK) and the University of Hong Kong (HKU), who provide medical training in HK. Attitude towards Euthanasia (ATE), measured using a five-point Likert Scale, was used to assess medical students' attitudes towards euthanasia. RESULTS: overall, 228 valid responses were received in 2021. The mean score of ATE was 29 (SD10.9), in which 134 (58.8%) of respondents showed a negative attitude towards euthanasia. Negative association was found between Christian (p-value = 0.003) and Catholic (p-value = 0.032) and the ATE score. Meanwhile, positive association was found between male gender (p-value = 0.011) and witnessed withdrawing of nutritional support from patient(s) (p-value = 0.011) and the ATE score. CONCLUSIONS: It is necessary for the government and schools to place more emphasis on euthanasia in the school curriculum by integrating ethical discussions and clinical attachment.


Assuntos
Eutanásia , Estudantes de Medicina , Idoso , Atitude , Atitude do Pessoal de Saúde , Estudos Transversais , Hong Kong , Humanos , Masculino , Inquéritos e Questionários
3.
Proc Natl Acad Sci U S A ; 118(37)2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34507989

RESUMO

The phosphoinositide 3-kinase regulatory subunit p85α is a key regulator of kinase signaling and is frequently mutated in cancers. In the present study, we showed that in addition to weakening the inhibitory interaction between p85α and p110α, a group of driver mutations in the p85α N-terminal SH2 domain activated EGFR, HER2, HER3, c-Met, and IGF-1R in a p110α-independent manner. Cancer cells expressing these mutations exhibited the activation of p110α and the AKT pathway. Interestingly, the activation of EGFR, HER2, and c-Met was attributed to the ability of driver mutations to inhibit HER3 ubiquitination and degradation. The resulting increase in HER3 protein levels promoted its heterodimerization with EGFR, HER2, and c-Met, as well as the allosteric activation of these dimerized partners; however, HER3 silencing abolished this transactivation. Accordingly, inhibitors of either AKT or the HER family reduced the oncogenicity of driver mutations. The combination of these inhibitors resulted in marked synergy. Taken together, our findings provide mechanistic insights and suggest therapeutic strategies targeting a class of recurrent p85α mutations.


Assuntos
Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Classe Ia de Fosfatidilinositol 3-Quinase/metabolismo , Domínio Catalítico/genética , Linhagem Celular Tumoral , Classe I de Fosfatidilinositol 3-Quinases/genética , Classe Ia de Fosfatidilinositol 3-Quinase/genética , Classe Ia de Fosfatidilinositol 3-Quinase/fisiologia , Células HCT116 , Humanos , Mutação , Neoplasias/genética , Fosfatidilinositol 3-Quinases/metabolismo , Domínios Proteicos/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Receptor ErbB-3/metabolismo , Transdução de Sinais , Domínios de Homologia de src
4.
BJR Open ; 3(1): 20210009, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34381950

RESUMO

OBJECTIVES: This study aimed to compare radiotherapy plan quality of coplanar volumetric modulated arc therapy (CO-VMAT) and non-coplanar VMAT (NC-VMAT) for post-operative primary brain tumour. METHODS: A total of 16 patients who were treated for primary brain tumours were retrospectively selected for this study. For each patient, identical CT sets with structures were used for both CO-VMAT and NC-VMAT planning. For CO-VMAT, one full arc and two coplanar half arcs were used. For NC-VMAT, one full coplanar and two non-coplanar half arcs with couch rotation of 315° or 45° were used. Dose constraints were adhered to the RTOG 0614, RTOG 0933 and TMH protocol. Dose volumetric parameters were collected for statistical analysis. RESULTS: .NC-VMAT achieved significant dose reduction in contralateral hippocampus, both temporal lobes and cochleae, and other OARs while the plan qualities remained the same. In particular, NC-VMAT decreased contralateral hippocampus mean dose by 1.67Gy. Similarly, the NC-VMAT decreased temporal lobe mean dose by 6.29Gy and 2.8Gy for ipsilateral and contralateral side respectively. Furthermore, it decreased cochlea mean dose by 5.34Gy and 0.97Gy for ipsilateral and contralateral side respectively. Overall, there was a reduction of 5.4% of normal brain tissue volume receiving low dose irradiation. CONCLUSION: The proposed NC-VMAT showed more favourable plan quality than the CO-VMAT for primary brain tumours, in particular to hippocampus, temporal lobes, cochleae and OARs located to the contralateral side of tumours. ADVANCES IN KNOWLEDGE: For primary brain tumours radiotherapy, NC-VMAT can reduce doses to the hippocampus, both temporal lobes, and cochleae, as well as OARs located to the contralateral side of tumours.

5.
Med Dosim ; 46(3): 219-228, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33483223

RESUMO

In prone breast radiation, as the medial tangential beam usually passes through the immobilization board and couch, it is necessary to quantify the attenuation effect and the potential skin dose enhancement from these external structures. The prone breast board studied consists of an insert on which the contralateral breast rests and a board base indexed to the couch. Two different Varian couch systems were also studied. Transmission factors (TF) of the board were measured using a Farmer chamber at 4 cm depth. Couch TFs were measured using a thimble chamber centered in a cylindrical phantom. A custom support model was created in the treatment planning system (TPS). TFs were then computed in the TPS for comparison. Selected clinical plans were recomputed in the TPS incorporating external structures for target coverage evaluation. The correction for the attenuation effect in the TPS was also demonstrated. Skin dose effects were evaluated using a Markus parallel plate chamber with a 1 mm buildup cap. Measured insert TFs ranged 0.976 to 0.983 for 6 MV and 0.990 to 0.999 for 23 MV. Board base TFs ranged 0.979 to 0.985 for 6 MV and 0.989 to 0.998 for 23 MV. TPS values agreed within 0.9% and 0.5% for the insert and board base, respectively. Assigned Hounsfield units (HUs) providing the best agreement were 200, -100, and -900 for the insert, the board "base shell" and "base inside," respectively. Varian Exact Couch and Exact IGRT Couch TFs varied with respect to couch angle, with minimum values of 0.837 and 0.956, respectively, for 6 MV. The clinical treatment volume (CTV) and whole breast receiving 95% of the prescription dose (CTV-V95 and WB-V95) of selected patients demonstrated reduced coverage due to attenuation of external structures. Close proximity to the base increased skin dose by up to 25% to 30%. Contacting the insert increased skin dose by 65% to 93% for 6 MV and 117% to 157% for 23 MV, respectively. Results have shown reduced coverage by attenuating external structures. Proper modeling of immobilization devices and couch structures in the TPS should be implemented for accurate dose calculation. Increased surface doses were observed due to direct contact to the insert or close proximity to the base. Further study is required to quantify such a skin dose enhancement effect and its correlation to clinically apparent skin effects and toxicity.


Assuntos
Radiometria , Planejamento da Radioterapia Assistida por Computador , Humanos , Posicionamento do Paciente , Imagens de Fantasmas
6.
Int J Mol Sci ; 21(16)2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32824277

RESUMO

In this study, we hypothesized that different strains of Lactobacillus can alleviate hyperlipidemia and liver steatosis via activation of 5' adenosine monophosphate-activated protein kinase (AMPK), an enzyme that is involved in cellular energy homeostasis, in aged rats. Male rats were fed with a high-fat diet (HFD) and injected with D-galactose daily over 12 weeks to induce aging. Treatments included (n = 6) (i) normal diet (ND), (ii) HFD, (iii) HFD-statin (lovastatin 2 mg/kg/day), (iv) HFD-Lactobacillus fermentum DR9 (10 log CFU/day), (v) HFD-Lactobacillus plantarum DR7 (10 log CFU/day), and (vi) HFD-Lactobacillus reuteri 8513d (10 log CFU/day). Rats administered with statin, DR9, and 8513d reduced serum total cholesterol levels after eight weeks (p < 0.05), while the administration of DR7 reduced serum triglycerides level after 12 weeks (p < 0.05) as compared to the HFD control. A more prominent effect was observed from the administration of DR7, where positive effects were observed, ranging from hepatic gene expressions to liver histology as compared to the control (p < 0.05); downregulation of hepatic lipid synthesis and ß-oxidation gene stearoyl-CoA desaturase 1 (SCD1), upregulation of hepatic sterol excretion genes of ATP-binding cassette subfamily G member 5 and 8 (ABCG5 and ABCG8), lesser degree of liver steatosis, and upregulation of hepatic energy metabolisms genes AMPKα1 and AMPKα2. Taken altogether, this study illustrated that the administration of selected Lactobacillus strains led to improved lipid profiles via activation of energy and lipid metabolisms, suggesting the potentials of Lactobacillus as a promising natural intervention for alleviation of cardiovascular and liver diseases.


Assuntos
Envelhecimento/metabolismo , Fígado Gorduroso/terapia , Hiperlipidemias/terapia , Probióticos/uso terapêutico , Proteínas Quinases/metabolismo , Quinases Proteína-Quinases Ativadas por AMP , Membro 5 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Membro 5 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Membro 8 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Membro 8 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Envelhecimento/patologia , Animais , Anticolesterolemiantes/farmacologia , Lactobacillus/patogenicidade , Metabolismo dos Lipídeos , Lipoproteínas/genética , Lipoproteínas/metabolismo , Fígado/efeitos dos fármacos , Fígado/crescimento & desenvolvimento , Fígado/metabolismo , Masculino , Probióticos/administração & dosagem , Proteínas Quinases/genética , Ratos , Ratos Sprague-Dawley , Estearoil-CoA Dessaturase/genética , Estearoil-CoA Dessaturase/metabolismo , Regulação para Cima
7.
Fungal Genet Biol ; 142: 103416, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32522620

RESUMO

Coprinopsis cinerea is a model mushroom-forming basidiomycete which produces basidiospores during sexual reproduction. This fungus is widely used to study fruiting body formation and development. Molecular mechanisms controlling its growth from vegetative mycelium to multicellular mature fruiting body have been studied extensively. However, little is known about the underlying biological processes during germ tube outgrowth or the transition from basidiospores to multinucleate hyphae. To better understand sexual spore germination in fungi, here we examined the time-dependent cellular events at resting, germinating and fully germinated basidiospores of C. cinerea by genome-wide transcriptional and post-transcriptional analyses and by carbohydrate composition analysis. Our results revealed a high demand of protein degradation, and biosynthesis of various compounds at the early stage of basidiospore gemination and dynamic changes of carbohydrate metabolism throughout the germination process. Seven microRNA-like RNAs (milRNAs) were identified in the resting basidiospores of C. cinerea, six of which were basidiospore-specific. Glycogen and trehalose were shown to be the carbon sources supporting the initiation of germ tube outgrowth. One basidiospore-specific milRNA, cci-milR-37, was found to be a potential regulator of glycogen metabolic pathways related to vegetative hyphal growth. Our results demonstrated the mRNA and miRNA-mediated regulation on energy production, protein and carbohydrate metabolisms at the early developmental stages of germ tube to form totipotent hyphae. To our knowledge, this is the first study to show the roles of miRNAs in mushroom basidiospore germination and out-growth.


Assuntos
Agaricales/genética , Genoma Fúngico/genética , MicroRNAs/genética , RNA Mensageiro/genética , Agaricales/crescimento & desenvolvimento , Regulação Fúngica da Expressão Gênica/genética , Células Germinativas/crescimento & desenvolvimento
8.
Probiotics Antimicrob Proteins ; 12(2): 545-562, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31301059

RESUMO

Both aging and diet play an important role in influencing the gut ecosystem. Using premature senescent rats induced by D-galactose and fed with high-fat diet, this study aims to investigate the effects of different potential probiotic strains on the dynamic changes of fecal microbiome and metabolites. In this study, male Sprague-Dawley rats were fed with high-fat diet and injected with D-galactose for 12 weeks to induce aging. The effect of Lactobacillus plantarum DR7, L. fermentum DR9, and L. reuteri 8513d administration on the fecal microbiota profile, short-chain fatty acids, and water-soluble compounds were analyzed. It was found that the administration of the selected strains altered the gut microbiota diversity and composition, even at the phylum level. The fecal short-chain fatty acid content was also higher in groups that were administered with the potential probiotic strains. Analysis of the fecal water-soluble metabolites revealed that administration of L. plantarum DR7 and L. reuteri 8513d led to higher fecal content of compounds related to amino acid metabolism such as tryptophan, leucine, tyrosine, cysteine, methionine, valine, and lysine; while administration of L. fermentum DR9 led to higher prevalence of compounds related to carbohydrate metabolism such as erythritol, xylitol, and arabitol. In conclusion, it was observed that different strains of lactobacilli can cause difference alteration in the gut microbiota and the metabolites, suggesting the urgency to explore the specific metabolic impact of specific strains on the host.


Assuntos
Envelhecimento , Fezes/microbiologia , Microbioma Gastrointestinal , Lactobacillus , Probióticos/administração & dosagem , Animais , Dieta Hiperlipídica/efeitos adversos , Ácidos Graxos Voláteis/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley
9.
Pharmacol Res ; 146: 104312, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31207344

RESUMO

Aging is closely associated with altered gut function and composition, in which elderly were reported with reduced gut microbiota diversity and increased incidence of age-related diseases. Probiotics have been shown to exert beneficial health-promoting effects through modulation of intestinal microflora biodiversity, thus the effects of probiotics administration on D-galactose (D-gal) senescence-induced rat were evaluated based on the changes in gut microbiota and metabolomic profiles. Upon senescence induction, the ratio of Firmicutes/ Bacteroidetes was significantly lowered, while treatment with Lactobacillus helveticus OFS 1515 and L. fermentum DR9 increased the ratio at the phylum level (P < 0.05). Study on the genus level showed that L. paracasei OFS 0291 and L. helveticus OFS 1515 administration reduced Bacteroides, which are prominently opportunistic pathogens while L. fermentum DR9 treated rats promoted the proliferation of Lactobacillus compared to the aged rats (P < 0.05). Probiotics treatment did not alter fecal short-chain fatty acid (SCFA) profile, but an increase in acetate was observed in the D-gal rats. The analysis of fecal water-soluble metabolites showed that D-gal induced senescence caused great impact on amino acids metabolism such as urocanic acid, citrulline, cystamine and 5-oxoproline, which could serve as potential aging biomarkers. Treatment with probiotics ameliorated these metabolites in a strain-specific manner, whereby L. fermentum DR9 promoted antioxidative effect through upregulation of oxoproline, whereas both L. paracasei OFS 0291 and L. helveticus OFS 1515 restored the levels of reducing sugars, arabinose and ribose similar to the young rats. D-gal induced senescence did cause significant immunological alteration in the colon of aged rats however, all probiotic strains demonstrated immunomodulatory properties as L. paracasei OFS 0291, L. helveticus OFS 1515 and L. fermentum DR9 alleviated proinflammatory cytokines TNF-α, IFN-γ and IL-1ß as well as IL-4 compared to the aged control (P < 0.05). Our study highlights the potential of probiotics as an anti-aging therapy through healthy gut modulation.


Assuntos
Envelhecimento/metabolismo , Envelhecimento/fisiologia , Microbioma Gastrointestinal/fisiologia , Lactobacillus/fisiologia , Microbiota/fisiologia , Animais , Colo/metabolismo , Colo/microbiologia , Citocinas/metabolismo , Fezes/microbiologia , Masculino , Modelos Animais , Probióticos/metabolismo , Ratos , Ratos Sprague-Dawley
10.
J Med Food ; 22(3): 230-240, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30183458

RESUMO

Changes in weather often trigger a myriad of negative impacts on the environment, which eventually affect human health. During the early months of 2016, Malaysia experienced El Niño, with an extremely dry season of almost zero rainfall. At the same time, an increase of more than twofold in fecal secretary immunoglobulin-A (SIgA) levels of healthy preschool children aged 2-6 years was observed, accompanied by an increase in phylum Bacteroidetes, predominantly attributed to genus Bacteroides and Odoribacter, which also positively correlated with fecal SIgA levels. Here, we present evidence to illustrate the detrimental effects of weather change on a microscopic "environment," the human gut ecosystem. We also discuss the protective effects of probiotic against dysbiosis as induced by weather change. The increase in Bacteroidetes was at an expense of decreased genus Faecalibacterium and Veillonella (phylum Firmicutes), whereas children consuming probiotic had a decrease in genus Collinsella, Atopobium, and Eggerthella (phylum Actinobacteria) instead.


Assuntos
Disbiose/prevenção & controle , El Niño Oscilação Sul , Microbioma Gastrointestinal , Probióticos/administração & dosagem , Substâncias Protetoras/administração & dosagem , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Saúde da Criança , Disbiose/microbiologia , Humanos , Tempo (Meteorologia)
11.
PLoS One ; 13(9): e0198234, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30231028

RESUMO

Coprinopsis cinerea is a model mushroom particularly suited for the study of fungal fruiting body development and the evolution of multicellularity in fungi. While microRNAs (miRNAs) have been extensively studied in animals and plants for their essential roles in post-transcriptional regulation of gene expression, miRNAs in fungi are less well characterized and their potential roles in controlling mushroom development remain unknown. To identify miRNA-like RNAs (milRNAs) in C. cinerea and explore their expression patterns during the early developmental transition of mushroom development, small RNA libraries of vegetative mycelium and primordium were generated and putative milRNA candidates were identified following the standards of miRNA prediction in animals and plants. Two out of 22 novel predicted milRNAs, cci-milR-12c and cci-milR-13e-5p, were validated by northern blot and stem-loop reverse transcription real-time PCR. Cci-milR-12c was differentially expressed whereas the expression levels of cci-milR-13e-5p were similar in the two developmental stages. Target prediction of the validated milRNAs resulted in genes associated with fruiting body development, including pheromone, hydrophobin, cytochrome P450, and protein kinase. Essential genes for miRNA biogenesis, including three coding for Dicer-like (DCL), one for Argonaute (AGO), one for AGO-like and one for quelling deficient-2 (QDE-2) proteins, were also identified in the C. cinerea genome. Phylogenetic analysis showed that the DCL and AGO proteins of C. cinerea were more closely related to those in other basidiomycetes and ascomycetes than to those in animals and plants. Taken together, our findings provided the first evidence for milRNAs in the model mushroom and their potential roles in regulating fruiting body development. New information on the evolutionary relationship of milRNA biogenesis proteins across kingdoms has also provided new insights for guiding further functional and evolutionary studies of miRNAs.


Assuntos
Coprinus/genética , Carpóforos/genética , MicroRNAs/genética , RNA Fúngico/genética , Sequência de Bases , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Genoma Fúngico , Genômica , Sequenciamento de Nucleotídeos em Larga Escala , Filogenia , Transcriptoma
12.
J Taibah Univ Med Sci ; 13(2): 135-141, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31435316

RESUMO

OBJECTIVES: Children are prone to contagious illnesses that come from peers in nurseries, kindergartens, and day care centres. The administration of probiotics has been reported to decrease the episodes of such illnesses, leading to decreased absences and consumption of antibiotics. With less emphasis on, and preferences for, blood collection from young subjects, quantifiable data are merely obtained from surveys and questionnaires. Malaysia has a population which is 25% ethnic Chinese. We aimed to develop a single tool that enables simultaneous assessments of both gastrointestinal and respiratory tract-related illnesses among young Chinese children. METHODS: The English-language validated questionnaires using data about demographics and monthly health records were translated into the Chinese language. Both forward and backward translated versions were validated. RESULTS: The developed demographic and monthly health questionnaires showed an overall item-level content validity index (I-CVI) of 0.99 and 0.97, respectively; while the translated Chinese versions showed I-CVI of 0.97 and 0.98, respectively. Item-level of response process validity index of 1.00 for this questionnaire was obtained from 30 respondents inferring that the items were clear and comprehensible. CONCLUSIONS: This study showed acceptable levels validity in the Chinese translated version, illustrating a valid and reliable tool to be used for simultaneous assessment of gastrointestinal and respiratory tract-related illnesses in young children that is applicable for Malaysia's Chinese population and other Chinese-speaking nations.

13.
Clin Ophthalmol ; 10: 1467-70, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27536060

RESUMO

Occasional reports of uveitis following topiramate use necessitated an investigation of relevant cases from safety databases and published biomedical literature. Data mining of the Food and Drug Administration Adverse Event Reporting System and cumulative review of cases from the global safety database (sponsor database) and published literature were conducted to assess association between topiramate use and uveitis. The Food and Drug Administration Adverse Event Reporting System search identified disproportional reporting of uveitis (n=23) and related terms (choroidal detachment, n=25; iridocyclitis, n=17). The postmarketing reporting frequency of uveitis and related events from the global safety database and based on an estimated topiramate exposure of 11,185,740 person-years from launch to April 2015 was 0.38 per 100,000 person-years and assigned as very rare. A total of 14 potential uveitis cases were identified from the cumulative review. Seven of these 14 cases were complicated by inadequate documentation, appearance of uveitic signs following drug withdrawal, or concurrent use of other sulfonamides. In acute angle-closure glaucoma and uveal effusions cases, insufficient evidence for underlying inflammation suggested that uveitis was not a component. Only seven of 14 cases were well documented, potentially topiramate-associated uveitis cases. Uveitis may occur in the setting of topiramate use only in very rare instances. Current evidence did not reveal a dose- or duration-dependent relationship between uveitis and topiramate use.

14.
Clin Lab ; 62(9): 1731-1737, 2016 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28164597

RESUMO

BACKGROUND: Keratoconus is an ocular degeneration characterized by the thinning of corneal stroma that may lead to varying degrees of myopia and visual impairment. Genetic factors have been reported in the pathology of keratoconus where Asians have a higher incidence, earlier onset, and undergo earlier corneal grafts compared to Caucasians. The visual system homeobox 1 (VSX1) gene forms part of a paired-like homeodomain transcription factor which is responsible for ocular development. The gene was marked as a candidate in genetic studies of keratoconus in various populations. Single nucleotide polymorphisms (SNPs) in the VSX1 gene have been reported to be associated with keratoconus. The detection of the SNPs involves DNA amplification of the VSX1 gene followed by genomic sequencing. Thus, the objective of this study aims to establish sensitive and accurate screening protocols for the molecular characterization of VSX1 polymorphisms. METHODS: Keratoconic (n = 74) and control subjects (n = 96) were recruited based on clinical diagnostic tests and selection criteria. DNA extracted from the blood samples was used to genotype VSX1 polymorphisms. In-house designed primers and optimization of PCR conditions were carried out to amplify exons 1 and 3 of the VSX1 gene. PCR conditions including percentage GC content, melting temperatures, and differences in melting temperatures of primers were evaluated to produce sensitive and specific DNA amplifications. RESULTS: Genotyping was successfully carried out in 4 exons of the VSX1 gene. Primer annealing temperatures were observed to be crucial in enhancing PCR sensitivity and specificity. Annealing temperatures were carefully evaluated to produce increased specificity, yet not allowing sensitivity to be compromised. In addition, exon 1 of the VSX1 gene was amplified using 2 different sets of primers to produce 2 smaller amplified products with absence of non-specific bands. DNA amplification of exons 1 and 3 consistently showed single band products which were successfully sequenced to yield reproducible data. CONCLUSIONS: The use of in-house designed primers and optimized PCR conditions allowed sensitive and specific DNA amplifications that produced distinct single bands. The in-house designed primers and DNA amplification protocols established in this study provide an addition to the current repertoire of primers for accurate molecular characterization of VSX1 gene polymorphisms in keratoconus research.


Assuntos
Primers do DNA/genética , Proteínas do Olho/genética , Proteínas de Homeodomínio/genética , Ceratocone/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Genes Homeobox , Testes Genéticos , Humanos , Malásia
15.
Cancer Lett ; 365(2): 182-9, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26070963

RESUMO

The oncogenic effects of autocrine human growth hormone (hGH) have been intensively investigated in estrogen receptor-positive mammary carcinoma (ER + MC) cells. We demonstrated herein that autocrine hGH promoted cancer stem cell (CSC)-like properties of estrogen receptor-negative mammary carcinoma (ER-MC) cells in vitro. In xenograft studies, autocrine hGH increased the tumor initiating capacity of ER-MC cells. We also observed that autocrine hGH promoted migration and invasion of ER-MC cells in vitro, and metastasis in vivo. Thus, inhibition of hGH is a potential therapeutic strategy to prevent tumor initiation and metastasis of ER-MC.


Assuntos
Neoplasias da Mama/patologia , Transformação Celular Neoplásica/patologia , Hormônio do Crescimento Humano/metabolismo , Células-Tronco Neoplásicas/patologia , Receptores de Estrogênio/metabolismo , Família Aldeído Desidrogenase 1 , Animais , Comunicação Autócrina , Movimento Celular/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Hormônio do Crescimento Humano/biossíntese , Hormônio do Crescimento Humano/genética , Humanos , Fator de Crescimento Insulin-Like I/biossíntese , Fator de Crescimento Insulin-Like I/genética , Isoenzimas/biossíntese , Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/secundário , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Transplante de Neoplasias , RNA Mensageiro/biossíntese , Retinal Desidrogenase/biossíntese , Esferoides Celulares , Transplante Heterólogo , Células Tumorais Cultivadas
16.
Wounds ; 26(5): 121-31, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-25856101

RESUMO

INTRODUCTION: Lactic acid bacteria (LAB) and bifidobacteria are able to produce antimicrobial compounds to inhibit opportunisticwounding skin pathogen. The antimicrobial compounds produced are organic acids, putative bacteriocin, hydrogen peroxide, and diacetyl. Staphylococcus epidermidis is well-known as an opportunistic wounding skin pathogen in wound infections related to implanted medical devices. OBJECTIVE: To screen 87 strains of LAB and 3 strains of bifidobacteria for antimicrobial activity against Staphylococcus epidermidis.Additionally, this study sought to determine and quantify types of antimicrobial compounds produced by LAB. MATERIALS AND METHODS: Inhibitory activity of LAB and bifidobacteria on S. epidermidis was assessed with the spectrophotometric method using a 96-well microplate reader. Characterization of cell-free supernatant (CFS) was done using analytical methods. Lactobacillus fermentum (collected by the Bioprocess Department at the Universiti Sains Malaysia [BD]) 1912d, Lactobacillus casei BD 1415b, Lactobacillus fermentum BD 8313a, Pediococcus pentosaceus BD 1913b, and Weissella cibaria (collected by the Food Technology Department at the Universiti Sains Malaysia [FTDC]) 8643 with high percentage of inhibition (P < 0.05), ranging from 73.7% to 88.2%, as compared to the control, were selected for subsequent analyses. Upon neutralization, the antimicrobial activity showed a drastic drop (P < 0.05) in the percentage of inhibition. Concentrations of the inhibitive metabolites were produced in varying amounts and were strain dependent. RESULTS: Results demonstrated that lactic acid in all strains was produced in a more predominant amount than acetic acid. Protein concentration production ranged from 0.081-0.215 mg/mL. L. fermentum BD 1912d yielded as much as 0.014 mg/mL hydrogen peroxide, which was significantly higher than other strains studied. Diacetyl was produced in a higher concentration by Weissella cibaria FTDC 8643 at 2.884 ng/mL; the lowest concentration of 0.465 ng/mL was produced by Ped. pentosaceus BD 1913b. CONCLUSION: Antimicrobial metabolites from CFS of lactic acid bacteria were effective in repressing the growth of opportunistic wounding dermal pathogen Staphylococcus epidermidis.

17.
Neurosci Bull ; 28(3): 259-70, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22622826

RESUMO

OBJECTIVE: Alzheimer's disease (AD) is one of the major disorders worldwide. Recent research suggests that the amyloid-ß precursor protein intracellular domain (AICD) is a potential contributor to AD development and progression. The small AICD is rapidly degraded after processing from the full-length protein. The present study aimed to apply a highly efficient biotinylation approach in vitro to study AICD-associated complexes in neurocytes. METHODS: By co-expressing Escherichia coli biotin ligase with biotinyl-tagged AICD in the SH-SY5Y neuronal cell line, the effects of AICD overexpression on cell proliferation and apoptosis were analyzed. Besides, AICD-associated nuclear transcriptional complexes were purified and then examined by mass spectrometry. RESULTS: Our data showed that AICD overexpression not only affected cell proliferation but also led to apoptosis in differentiated SH-SY5Y cells. Moreover, biotinylation allowed single-step purification of biotinylated AICD-associated complexes from total nuclear extract via high-affinity biotin-streptavidin binding. Following this by mass spectrometry, we identified physically associated proteins, some reported previously and other novel binding partners, CUX1 and SPT5. CONCLUSION: Based on these results, a map of the AICD-associated nuclear interactome was depicted. Specifically, AICD can activate CUX1 transcriptional activity, which may be associated with AICD-dependent neuronal cell death. This work helps to understand the AICD-associated biological events in AD progression and provides novel insights into the development of AD.


Assuntos
Precursor de Proteína beta-Amiloide/química , Precursor de Proteína beta-Amiloide/metabolismo , Apoptose , Proliferação de Células , Neurônios/metabolismo , Linhagem Celular Tumoral , Humanos , Neurônios/citologia , Estrutura Terciária de Proteína , Transcrição Gênica
18.
Hong Kong Med J ; 14(2): 148-51, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18382024

RESUMO

We report a case of umbilical cord ulceration associated with obstruction of the duodeno-jejunal junction by a peritoneal band. Umbilical cord ulceration is a rare condition; a literature review identified a total of 17 cases only. In all cases, the ulceration was associated with congenital intestinal obstruction. Cord ulceration usually presents as sudden foetal deterioration due to foetal haemorrhage. This condition is associated with high perinatal mortality and morbidity. The causes of this condition are still unknown, and prenatal diagnosis is difficult. Awareness of the possible association between umbilical cord ulceration and intestinal obstruction, and of the need to deliver such pregnancies immediately when an abnormal foetal heart rate pattern develops might be the only means of preventing intrauterine death and improving neonatal outcomes.


Assuntos
Hemorragia/patologia , Músculo Liso Vascular/patologia , Natimorto , Úlcera/patologia , Cordão Umbilical/patologia , Adulto , Feminino , Humanos , Recém-Nascido , Atresia Intestinal/patologia , Jejuno/anormalidades , Jejuno/patologia , Gravidez , Artérias Umbilicais/patologia
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