Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 25
Filter
1.
Eur Rev Med Pharmacol Sci ; 28(5): 1641-1650, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38497849

ABSTRACT

OBJECTIVE: The pathogenesis of doxorubicin (DOX) induced cardiomyopathy (DCM) is still uncertain. We aimed to identify the critical genes and pathways involved in DCM based on bioinformatics analysis. MATERIALS AND METHODS: The GSE59672 and GSE23598 mice heart tissue microarray data were obtained from Gene Expression Omnibus (GEO) database. The "limma" package of R software was used to screen the differently expressed genes (DEGs). GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) analyses were performed on DEGs by using "clusterProfiler" package in R software. The PPI (Protein - Protein Interaction) network of DEGs constructed by STRING online database and thereby the top 15 hub genes selected by cytoHubba in Cytoscape software. The hub genes interaction was performed by GeneMANIA online database. The "Corrplot" R package was employed to assess hub genes correlation. RESULTS: Finally, a total of 492 and 501 DEGs were screened in GSE59672 and GSE23598 datasets, respectively. GO analyses revealed that DEGs were mainly involved in the regulation of extracellular matrix organization, metabolic process, regulation of collagen-containing extracellular matrix. KEGG pathway analyses indicated that DEGs were mainly involved in protein digestion and absorption, ECM-receptor interaction, phagosome, and p53 signaling pathway. Finally, the 8 hub genes were identified, including Col1a1, Col3a1, Col1a2, Col6a1, Ptprc, Tyrobp, Itgb2, and Ctss. CONCLUSIONS: The present study identified a series of key genes, including Col1a1, Col3a1, Col1a2, Col6a1, Ptprc, Tyrobp, Itgb2, and Ctss. In addition, important pathways were also discovered. The results of this study may provide a novel molecular mechanism and potential therapeutic targets for DCM.


Subject(s)
Cardiomyopathies , Animals , Mice , Cardiomyopathies/chemically induced , Cardiomyopathies/genetics , CD18 Antigens , Computational Biology , Databases, Factual , Doxorubicin/adverse effects
2.
3.
Public Health ; 202: 12-17, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34875531

ABSTRACT

OBJECTIVES: Accurate assessment of early non-alcoholic fatty liver disease (NAFLD) is important to reduce the possible complications. The purpose of the present study was to develop a simple algorithm for the screening of NAFLD in the Chinese population based on routine anthropometric data and laboratory tests. STUDY DESIGN: This is a cross-sectional design. METHODS: The subjects (1145) underwent routine physical examinations. The variables in the NAFLD index (NFI) were obtained by a stepwise multiple logistic regression analysis on 1000 bootstrap samples. The area under the receiver-operating characteristic (AUROC) was used to evaluate the accuracy of the NFI. RESULTS: Multivariate analysis showed that body mass index, fasting blood glucose, ratio of alanine aminotransferase to aspartate aminotransferase, and triglyceride were included in the final equation. The AUROC of the NFI was 0.919 (95% confidence interval = 0.901-0.937). An NFI of <31.0 excluded the possibility of NAFLD with a sensitivity of 96.9%, and at a value of >36.0, the NFI could detect NAFLD with a specificity of 98.9%. CONCLUSIONS: NFI was a cost-effective NAFLD-screening model, which had a high accuracy for predicting NAFLD at early stages in the Chinese population.


Subject(s)
Non-alcoholic Fatty Liver Disease , Alanine Transaminase , China , Cross-Sectional Studies , Humans , Triglycerides
4.
J Nutr Health Aging ; 23(5): 451-458, 2019.
Article in English | MEDLINE | ID: mdl-31021362

ABSTRACT

BACKGROUND: The loss of muscle mass, strength and function associated with increasing age has various health ramifications, including the elevated risk for falls, fractures, frailty, poor quality of life, and mortality. Several studies have confirmed the effects of protein supplementation and RT (resistance training) for this age-related change independently, but whether a combination of the two produces a stronger effect remains controversial. OBJECTIVE: This study aims to explore whether a combination of protein supplementation and RT leads to reduction of muscle mass, strength and function in the elderly. METHODS: We retrieved RCTs (randomized controlled trials) reporting the effects of protein supplementation combined with RT on muscle mass, strength and function in the elderly, published before May 2018 through PubMed, MEDLINE, Embase, and manual searches. RESULTS: Twenty-one RCTs were included, involving 1,249 participants. The results showed that protein supplementation combine with RT significantly enhances the muscle mass and strength of the older adults, where FFM (fat-free mass) increased by 0.23 kg (95% CI: 0.09, 0.38; P=0.002), ASMM (appendicular skeletal muscle mass) by 0.39 kg (95% CI: 0.14, 0.64; P=0.002), handgrip strength by 0.29 kg (95% CI: 0.08, 0.50; P=0.008), knee extension strength by 0.27 kg (95% CI: 0.06, 0.47; P=0.013), leg press strength by 0.33 kg (95% CI: 0.01, 0.64; P=0.04), but no significant effects were seen on muscle function. CONCLUSION: Compared to simple RT, protein supplementation combine with RT is more effective in enhancing the muscle mass and strength in the elderly, and the findings do not support the benefit of combination treatment for muscle function.


Subject(s)
Dietary Supplements/analysis , Muscle Strength/drug effects , Muscle, Skeletal/drug effects , Quality of Life/psychology , Resistance Training/methods , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Randomized Controlled Trials as Topic
5.
Surg Neurol Int ; 9: 15, 2018.
Article in English | MEDLINE | ID: mdl-29497568

ABSTRACT

BACKGROUND: Keratinous or epidermoid cysts (ECs) are encapsulated lesions lined by squamous cell epithelium. They comprise approximately 1% of intracranial lesions. Contrary to dermoid cysts, they lack dermal elements such as sebaceous or apocrine glands and hair follicles. The sellar region is the second most common intracranial site following the cerebellopontine angle. Here, we report a case of EC in a patient who complained of endocrine disturbances. We also performed a systematic review on previously published cases to analyze clinical and radiological characteristics and report the treatment outcomes of suprasellar ECs. CASE DESCRIPTION: A 42-year-old woman presented with a one-year history of amenorrhea, weight gain, severe headache, and visual disturbances for 6 months. Work-up identified an elevated prolactin level and a temporal field defect of the right eye. Magnetic resonance imaging (MRI) showed a cystic suprasellar lesion pushing on the optic chiasm. She underwent endoscopic trans-sphenoidal surgery, which confirmed a keratinous cyst on histology. Postoperatively, complete resection was confirmed on imaging. She did well although her hospital stay was prolonged due to diabetes insipidus and hypocortisolism. CONCLUSION: Chronic endocrine disturbances can be the presenting complaints of a suprasellar EC, whose T1-weighted MRI appearance can be non-specific, mimicking other differential diagnoses, such as a Rathke's cleft cyst. However, the T2-weighted MRI appearances of ECs are generally hyper-intense and lesions show diffusion restriction. Treatment is surgical and yields good outcomes in most cases reported.

7.
Sci Rep ; 6: 35967, 2016 10 25.
Article in English | MEDLINE | ID: mdl-27779239

ABSTRACT

The temperature evolution of icosahedral medium-range order formed by interpenetrating icosahedra in CuZr metallic glassforming liquids was investigated via molecular dynamics simulations. Scaling analysis based on percolation theory was employed, and it is found that the size distribution of clusters formed by the central atoms of icosahedra at various temperatures follows a very good scaling law with the cluster number density scaled by S-τ and the cluster size S scaled by |1 - Tc/T|-1/σ, respectively. Here Tc is scaling crossover-temperature. τ and σ are scaling exponents. The critical scaling behaviour suggests that there would be a structural phase transition manifested by percolation of locally favoured structures underlying the glass transition, if the liquid could be cooled slowly enough but without crystallization intervening. Furthermore, it is revealed that when icosahedral short-range order (ISRO) extends to medium-range length scale by connection, the atomic configurations of ISROs will be optimized from distorted ones towards more regular ones gradually, which significantly lowers the energies of ISROs and introduces geometric frustration simultaneously. Both factors make key impacts on the drastic dynamic slow-down of supercooled liquids. Our findings provide direct structure-property relationship for understanding the nature of glass transition.

8.
Article in Chinese | MEDLINE | ID: mdl-27514424

ABSTRACT

OBJECTIVE: To investigate the impact of coal workers' pneumoconiosis complicated by the pathological changes in lymph nodes in lung cancer on surgical treatment. METHODS: A total of 63 patients with non-small cell lung cancer who received pulmonary lobectomy and systemic mediastinal lymph node dissection were enrolled and divided into the group with coal workers' pneumoconiosis complicated by lung cancer (30 patients) and the non-pneumoconiosis liver cancer group (33 patients). The short-term outcome was compared between the two groups and confirmed by lymph node fibrosis shown by postoperative pathological examination. The predictive value of lymphadenectasis on chest CT was analyzed. RESULTS: Compared with the non-pneumoconiosis liver cancer group, the group with coal workers' pneumoconiosis complicated by lung cancer had significant increases in time of operation, intraoperative blood loss, postoperative extubation time, and length of hospital stay (P<0.05). The patients were divided into groups according to the presence or absence of lymph node fibrosis, and the group with lymph node fibrosis had a significantly longer time of operation and greater intraoperative blood loss than the group without lymph node fibrosis (P<0.05). CONCLUSION: When coal workers' pneumoconiosis is complicated by lung cancer, severe lymph node fibrosis often causes difficulties in surgery, and thoracotomy may be a safe and effective therapeutic method.


Subject(s)
Anthracosis , Carcinoma, Non-Small-Cell Lung , Coal Mining , Lung Neoplasms , Coal , Fibrosis , Humans , Lung/pathology , Lymph Nodes , Pneumonectomy , Tomography, X-Ray Computed
9.
Breast Cancer Res Treat ; 153(1): 89-99, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26227474

ABSTRACT

Mammographic density (MD) adjusted for age and body mass index is one of the strongest known risk factors for breast cancer. Given the high attributable risk of MD for breast cancer, chemoprevention with a safe and available agent that reduces MD and breast cancer risk would be beneficial. Cox-2 has been implicated in MD-related breast cancer risk, and was increased in stromal cells in high MD tissues in one study. Our study assessed differential Cox-2 expression in epithelial and stromal cells in paired samples of high and low MD human breast tissue, and in a validated xenograft biochamber model of MD. We also examined the effects of endocrine treatment upon Cox-2 expression in high and low MD tissues in the MD xenograft model. Paired high and low MD human breast tissue samples were immunostained for Cox-2, then assessed for differential expression and staining intensity in epithelial and stromal cells. High and low MD human breast tissues were separately maintained in biochambers in mice treated with Tamoxifen, oestrogen or placebo implants, then assessed for percentage Cox-2 staining in epithelial and stromal cells. Percentage Cox-2 staining was greater for both epithelial (p = 0.01) and stromal cells (p < 0.0001) of high compared with low MD breast tissues. In high MD biochamber tissues, percentage Cox-2 staining was greater in stromal cells of oestrogen-treated versus placebo-treated tissues (p = 0.05).


Subject(s)
Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cyclooxygenase 2/metabolism , Epithelial Cells/metabolism , Stromal Cells/metabolism , Adult , Animals , Breast/metabolism , Breast/pathology , Breast Density , Cyclooxygenase 2/genetics , Disease Models, Animal , Female , Gene Expression , Heterografts , Humans , Immunohistochemistry , Mammary Glands, Human/abnormalities , Mice , Middle Aged
10.
Breast Cancer Res Treat ; 148(2): 303-14, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25332094

ABSTRACT

Mammographic density (MD) is a strong risk factor for breast cancer. It is altered by exogenous endocrine treatments, including hormone replacement therapy and Tamoxifen. Such agents also modify breast cancer (BC) risk. However, the biomolecular basis of how systemic endocrine therapy modifies MD and MD-associated BC risk is poorly understood. This study aims to determine whether our xenograft biochamber model can be used to study the effectiveness of therapies aimed at modulating MD, by examine the effects of Tamoxifen and oestrogen on histologic and radiographic changes in high and low MD tissues maintained within the biochamber model. High and low MD human tissues were precisely sampled under radiographic guidance from prophylactic mastectomy fresh specimens of high-risk women, then inserted into separate vascularized murine biochambers. The murine hosts were concurrently implanted with Tamoxifen, oestrogen or placebo pellets, and the high and low MD biochamber tissues maintained in the murine host environment for 3 months, before the high and low MD biochamber tissues were harvested for histologic and radiographic analyses. The radiographic density of high MD tissue maintained in murine biochambers was decreased in Tamoxifen-treated mice compared to oestrogen-treated mice (p = 0.02). Tamoxifen treatment of high MD tissue in SCID mice led to a decrease in stromal (p = 0.009), and an increase in adipose (p = 0.023) percent areas, compared to placebo-treated mice. No histologic or radiographic differences were observed in low MD biochamber tissue with any treatment. High MD biochamber tissues maintained in mice implanted with Tamoxifen, oestrogen or placebo pellets had dynamic and measurable histologic compositional and radiographic changes. This further validates the dynamic nature of the MD xenograft model, and suggests the biochamber model may be useful for assessing the underlying molecular pathways of Tamoxifen-reduced MD, and in testing of other pharmacologic interventions in a preclinical model of high MD.


Subject(s)
Breast Neoplasms/diagnostic imaging , Breast Neoplasms/pathology , Estrogens/pharmacology , Mammary Glands, Human/abnormalities , Mammography , Tamoxifen/pharmacology , Animals , Antineoplastic Agents, Hormonal/pharmacology , Breast Density , Breast Neoplasms/drug therapy , Female , Humans , Mammary Glands, Human/drug effects , Mammary Glands, Human/pathology , Mice , Mice, SCID , Tissue Engineering , Tissue Transplantation , Transplantation, Heterologous
11.
Breast Cancer Res Treat ; 144(3): 479-502, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24615497

ABSTRACT

There has been considerable recent interest in the genetic, biological and epidemiological basis of mammographic density (MD), and the search for causative links between MD and breast cancer (BC) risk. This report will critically review the current literature on MD and summarize the current evidence for its association with BC. Keywords 'mammographic dens*', 'dense mammary tissue' or 'percent dens*' were used to search the existing literature in English on PubMed and Medline. All reports were critically analyzed. The data were assigned to one of the following aspects of MD: general association with BC, its relationship with the breast hormonal milieu, the cellular basis of MD, the generic variations of MD, and its significance in the clinical setting. MD adjusted for age, and BMI is associated with increased risk of BC diagnosis, advanced tumour stage at diagnosis and increased risk of both local recurrence and second primary cancers. The MD measures that predict BC risk have high heritability, and to date several genetic markers associated with BC risk have been found to also be associated with these MD risk predictors. Change in MD could be a predictor of the extent of chemoprevention with tamoxifen. Although the biological and genetic pathways that determine and perhaps modulate MD remain largely unresolved, significant inroads are being made into the understanding of MD, which may lead to benefits in clinical screening, assessment and treatment strategies. This review provides a timely update on the current understanding of MD's association with BC risk.


Subject(s)
Breast Neoplasms/diagnostic imaging , Breast Neoplasms/pathology , Breast/pathology , Mammary Glands, Human/abnormalities , Mammography , Breast Density , Breast Neoplasms/drug therapy , Breast Neoplasms/etiology , Breast Neoplasms/mortality , Female , Hormone Replacement Therapy , Humans , Neoplasm Recurrence, Local , Prognosis , Risk Factors
12.
Cell Death Dis ; 4: e907, 2013 Nov 07.
Article in English | MEDLINE | ID: mdl-24201806

ABSTRACT

The androgen receptor (AR) has a critical role in promoting androgen-dependent and -independent apoptosis in testicular cells. However, the molecular mechanisms that underlie the ligand-independent apoptosis, including the activity of AR in testicular stem cells, are not completely understood. In the present study, we generated induced pluripotent stem cells (iPSCs) from bovine testicular cells by electroporation of octamer-binding transcription factor 4 (OCT4). The cells were supplemented with leukemia inhibitory factor and bone morphogenetic protein 4, which maintained and stabilized the expression of stemness genes and pluripotency. The iPSCs were used to assess the apoptosis activity following exposure to phthalate esters, including di (2-ethyhexyl) phthalates, di (n-butyl) phthalate, and butyl benzyl phthalate. Phthalate esters significantly reduced the expression of AR in iPSCs and induced a higher ratio of BAX/BCL-2, thereby favoring apoptosis. Phthalate esters also increased the expression of cyclin-dependent kinase inhibitor 1 (p21(Cip1)) in a p53-dependent manner and enhanced the transcriptional activity of p53. The forced expression of AR and knockdown of p21(Cip1) led to the rescue of the phthalate-mediated apoptosis. Overall, this study suggests that testicular iPSCs are a useful system for screening the toxicity of environmental disruptors and examining their effect on the maintenance of stemness and pluripotency, as well as for identifying the iPSC signaling pathway(s) that are deregulated by these chemicals.


Subject(s)
Induced Pluripotent Stem Cells/drug effects , Induced Pluripotent Stem Cells/metabolism , Phthalic Acids/pharmacology , Receptors, Androgen/metabolism , Testis/cytology , Animals , Apoptosis/drug effects , Apoptosis/genetics , Cattle , Cellular Reprogramming/drug effects , Cellular Reprogramming/genetics , Induced Pluripotent Stem Cells/cytology , Male , Receptors, Androgen/genetics , Signal Transduction/drug effects , Tumor Suppressor Protein p53
13.
Breast Cancer Res Treat ; 140(2): 285-97, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23881524

ABSTRACT

Mammographic density (MD) is a strong heritable risk factor for breast cancer, and may decrease with increasing parity. However, the biomolecular basis for MD-associated breast cancer remains unclear, and systemic hormonal effects on MD-associated risk is poorly understood. This study assessed the effect of murine peripartum states on high and low MD tissue maintained in a xenograft model of human MD. Method High and low MD human breast tissues were precisely sampled under radiographic guidance from prophylactic mastectomy specimens of women. The high and low MD tissues were maintained in separate vascularised biochambers in nulliparous or pregnant SCID mice for 4 weeks, or mice undergoing postpartum involution or lactation for three additional weeks. High and low MD biochamber material was harvested for histologic and radiographic comparisons during various murine peripartum states. High and low MD biochamber tissues in nulliparous mice were harvested at different timepoints for histologic and radiographic comparisons. Results High MD biochamber tissues had decreased stromal (p = 0.0027), increased adipose (p = 0.0003) and a trend to increased glandular tissue areas (p = 0.076) after murine postpartum involution. Stromal areas decreased (p = 0.042), while glandular (p = 0.001) and adipose areas (p = 0.009) increased in high MD biochamber tissues during lactation. A difference in radiographic density was observed in high (p = 0.0021) or low MD biochamber tissues (p = 0.004) between nulliparous, pregnant and involution groups. No differences in tissue composition were observed in high or low MD biochamber tissues maintained for different durations, although radiographic density increased over time. Conclusion High MD biochamber tissues had measurable histologic changes after postpartum involution or lactation. Alterations in radiographic density occurred in biochamber tissues between different peripartum states and over time. These findings demonstrate the dynamic nature of the human MD xenograft model, providing a platform for studying the biomolecular basis of MD-associated cancer risk.


Subject(s)
Breast Neoplasms/pathology , Breast/growth & development , Mammary Glands, Human/abnormalities , Tissue Engineering , Animals , Breast/pathology , Breast Density , Breast Neoplasms/genetics , Female , Humans , Mammography , Mice , Peripartum Period , Pregnancy
14.
Breast Cancer Res Treat ; 135(1): 177-87, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22729891

ABSTRACT

Mammographic density (MD) is the area of breast tissue that appears radiologically white on mammography. Although high MD is a strong risk factor for breast cancer, independent of BRCA1/2 mutation status, the molecular basis of high MD and its associated breast cancer risk is poorly understood. MD studies will benefit from an animal model, where hormonal, gene and drug perturbations on MD can be measured in a preclinical context. High and low MD tissues were selectively sampled by stereotactic biopsy from operative specimens of high-risk women undergoing prophylactic mastectomy. The high and low MD tissues were transferred into separate vascularised biochambers in the groins of SCID mice. Chamber material was harvested after 6 weeks for histological analyses and immunohistochemistry for cytokeratins, vimentin and a human-specific mitochondrial antigen. Within-individual analysis was performed in replicate mice, eliminating confounding by age, body mass index and process-related factors, and comparisons were made to the parental human tissue. Maintenance of differential MD post-propagation was assessed radiographically. Immunohistochemical staining confirmed the preservation of human glandular and stromal components in the murine biochambers, with maintenance of radiographic MD differential. Propagated high MD regions had higher stromal (p = 0.0002) and lower adipose (p = 0.0006) composition, reflecting the findings in the original human breast tissue, although glands appeared small and non-complex in both high and low MD groups. No significant differences were observed in glandular area (p = 0.4) or count (p = 0.4) between high and low MD biochamber tissues. Human mammary glandular and stromal tissues were viably maintained in murine biochambers, with preservation of differential radiographic density and histological features. Our study provides a murine model for future studies into the biomolecular basis of MD as a risk factor for breast cancer.


Subject(s)
Breast Neoplasms/pathology , Breast/pathology , Mammography , Tissue Engineering , Animals , Breast/physiology , Breast/transplantation , Breast Neoplasms/diagnostic imaging , Female , Humans , Mice , Mice, SCID , Stromal Cells , Tissue Transplantation , Transplantation, Heterologous
15.
J Dairy Res ; 77(4): 487-97, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20822569

ABSTRACT

Our previous studies demonstrated prompt elevation of proteinase activity in mammary secretion of drying-off cows and goats. The current study examined the progressive changes in composition of cow mammary secretion following drying-off and, in parallel, characterized the mode of peptide neogenesis using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and liquid chromatography-electrospray-ionization (LC-ESI) MS/MS. The results show that the percentage of casein of total milk protein at time of drying-off was 76%, which dropped to 41%, 24%, and 16%, respectively, 1, 2, and 3 weeks after drying-off. Levels of ß-lactoglobulin and α-lactoalbumin in mammary secretions of drying-off cows decreased prominently while levels of lactoferrin, BSA, and casein derived-proteins increased concomitantly compared with regular milk. A fractionation procedure was applied to remove molecules larger than 10 kDa before MALDI-TOF MS and LC-ESI MS/MS and the results show that the MALDI-TOF MS peptide profile of mammary secretion ranging from m/z 600 to 4000 was apparently modified after drying-off for 1 week, whereas species 1590 m/z and 2460 m/z were most obviously enriched compared with regular milk. LC-ESI MS/MS results were used to map peptide sequence with Mascot search server and under no post translational modification to reduce database size and 202 novel ß-casein-derived peptides were successfully identified in mammary secretion after drying-off for 1 week in contrast to regular milk. Accordingly at least 48 additional cleavage positions were assigned on ß-casein for mammary secretion. Among the 202 novel peptides, 5 are homologous with confirmed opioid agonists, angiotensin 1-converting enzyme inhibitors, or immuno-modulators. In conclusion, peptides are released in situ from milk proteins within short intervals following drying-off in cows. They might play roles in the transition of mammary glands from lactating to non-lactating. With specified post-translational modifications and focused functional screening, novel peptides are yet to be discovered in dry cow mammary secretion.


Subject(s)
Cattle/physiology , Lactation/physiology , Milk Proteins/chemistry , Milk/chemistry , Amino Acid Sequence , Animals , Female , Filtration , Mammary Glands, Animal/physiology , Milk/physiology , Molecular Sequence Data , Peptides/chemistry , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
16.
Inflammopharmacology ; 16(5): 248-52, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18815735

ABSTRACT

The health benefits of green tea and its main constituent (-)-epigallocatechin gallate [(-)-EGCG] have been widely supported by results from epidemiological, cell culture, animal and clinical studies. On the other hand, there are a number of issues, such as stability, bioavailability and metabolic transformations under physiological conditions, facing the development of green tea polyphenols into therapeutic agents. We previously reported that the synthetic peracetate of (-)-EGCG has improved stability and better bioavailability than (-)-EGCG itself and can act as pro-drug under both in vitro and in vivo conditions. Analogs of catechins have been synthesized and their structure activity relationship provides an understanding to the mechanism of proteasome inhibition. Metabolic methylation of catechins leading to methylated (-)-EGCG may alter the biological activities of these compounds.


Subject(s)
Catechin/analogs & derivatives , Tea/chemistry , Biological Availability , Biotransformation , Catechin/chemical synthesis , Catechin/isolation & purification , Catechin/pharmacokinetics , Catechin/therapeutic use , Humans , Structure-Activity Relationship
17.
Inflammopharmacology ; 16(5): 208-12, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18815743

ABSTRACT

The cancer-preventive effects of green tea and its main constituent (-)-epigallocatechin gallate [(-)-EGCG] are widely supported by results from epidemiological, cell culture, animal and clinical studies although the molecular target has not been well defined. We previously reported that ester bond-containing tea polyphenols, e. g. (-)-EGCG, and their synthetic analogs potently and specifically inhibited the proteasomal activity. Subsequently, we further demonstrated that methylation on green tea polyphenols under physiological conditions decreased their proteasome-inhibitory activity, contributing to decreased cancer-preventive effects of tea consumption. Since (-)-EGCG is unstable under physiological conditions, we also developed the peracetate-protected or prodrug form of (-)-EGCG, Pro-EGCG (1), and shown that Pro-EGCG (1) increases the bioavailability, stability, and proteasome-inhibitory and anticancer activities of (-)-EGCG in human breast cancer cells and xenografts, suggesting its potential use for cancer prevention and treatment.


Subject(s)
Anticarcinogenic Agents/pharmacology , Catechin/analogs & derivatives , Proteasome Inhibitors , Tea , Catechin/pharmacology , Methylation , Ubiquitin/metabolism
18.
Histol Histopathol ; 23(4): 487-96, 2008 04.
Article in English | MEDLINE | ID: mdl-18228206

ABSTRACT

Tea is the most popular beverage in the world, second only to water. Tea contains an infusion of the leaves from the Camellia sinensis plant rich in polyphenolic compounds known as catechins, the most abundant of which is (-)-EGCG. Although tea has been consumed for centuries, it has only recently been studied extensively as a health-promoting beverage that may act to prevent a number of chronic diseases and cancers. The results of several investigations indicate that green tea consumption may be of modest benefit in reducing the plasma concentration of cholesterol and preventing atherosclerosis. Additionally, the cancer-preventive effects of green tea are widely supported by results from epidemiological, cell culture, animal and clinical studies. In vitro cell culture studies show that tea polyphenols potently induce apoptotic cell death and cell cycle arrest in tumor cells but not in their normal cell counterparts. Green tea polyphenols were shown to affect several biological pathways, including growth factor-mediated pathway, the mitogen-activated protein (MAP) kinase-dependent pathway, and ubiquitin/proteasome degradation pathways. Various animal studies have revealed that treatment with green tea inhibits tumor incidence and multiplicity in different organ sites such as skin, lung, liver, stomach, mammary gland and colon. Recently, phase I and II clinical trials have been conducted to explore the anticancer effects of green tea in humans. A major challenge of cancer prevention is to integrate new molecular findings into clinical practice. Therefore, identification of more molecular targets and biomarkers for tea polyphenols is essential for improving the design of green tea trials and will greatly assist in a better understanding of the mechanisms underlying its anti-cancer activity.


Subject(s)
Anticarcinogenic Agents/pharmacology , Flavonoids/pharmacology , Neoplasms/prevention & control , Phenols/pharmacology , Tea , Animals , Apoptosis/drug effects , Clinical Trials, Phase I as Topic , Clinical Trials, Phase II as Topic , Flavonoids/chemistry , Flavonoids/therapeutic use , Humans , MAP Kinase Signaling System , Molecular Structure , Neoplasms/drug therapy , Neoplasms/epidemiology , Neoplasms/metabolism , Neoplasms/pathology , Phenols/chemistry , Phenols/therapeutic use , Polyphenols , Proteasome Endopeptidase Complex/metabolism , Signal Transduction , Ubiquitin/metabolism
19.
Environ Technol ; 28(7): 731-41, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17674646

ABSTRACT

The environmental impact of endocrine disrupting chemicals (EDC) has been intensively researched over the last 10 years in the academic field. One of the observations highlighted has been the relationship between feminization of male fish (known as intersex) and the discharge of steroid estrogens from sewage treatment works (STWs). Compounds that act like estrogens found in certain industrial chemicals have also been blamed for such an effect. Given the long-term effect this may have on fish population, it is anticipated that EDC removal may be imposed in the future discharge consent to ensure the concentration not exceeding a Predicted No Effect Concentration (PNEC), taking into account the dilution capacity in the receiving water. Currently, there is a lack of understanding as to how the steroid estrogens and other EDCs are removed through various wastewater treatment processes. To ensure that future policy decisions are well founded, the Environment Agency (EA) and Department for Environment Food and Rural Affairs (Defra) have instigated a Demonstration Programme, which involves collecting baseline data at 17 STWs across the UK and investment to achieve EDC reduction at 2 full-scale STWs. This paper focuses on the baseline data element of the Demonstration Programme. Given the complexity of the programme, and the technical issues to be resolved it was seen as beneficial to trial the protocol at one or two sites to inform the remainder of the Demonstration Programme. Having a strong analytical capability, Anglian Water Services (AWS) has agreed to take this leading role.


Subject(s)
Endocrine Disruptors/chemistry , Environmental Monitoring/methods , Sewage/chemistry , Water Pollutants, Chemical/chemistry , Water Purification/methods , Animals , Endocrine Disruptors/analysis , Endocrine Disruptors/isolation & purification , Fishes/metabolism , Male , United Kingdom , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/isolation & purification
20.
Environ Technol ; 26(2): 199-209, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15791801

ABSTRACT

In the UK water industry, the sequencing batch reactor (SBR) has been seen as a technically-economically advantageous option as an alternative to the continuous flow activated sludge process (ASP). The technology has enjoyed a booming period over the last decade, with many installations now operational. These installations appear to have achieved various degrees of success, but not without operational and performance issues. This paper reviews the typical design practices of SBR, and focuses on one particular SBR supplied by Biobubble Ltd within the spectrum of various SBR technologies. Biobubble SBR is designed as a true SBR with discrete phases of fill, aerate, settle and decant. It often guarantees an effluent quality of 15: 10: 2 (TSS : BOD : AmmN) and a low sludge production. Its main operating parameters are distinct in comparison with continuous flow ASP, and indeed other 'mainstream' SBRs. Differentiation can be seen on plant sizing, sequence control and equipment configuration. Studies have been carried out by Anglian Water Services Ltd to gain a better understanding of this type of SBRs. It has been found that the reliable performance is due to the long hydraulic retention time (HRT) of about 70 hours (aerated), which provide high,tolerance against shock loadings. The good settlement is a result of a long settling phase of 1.5 hours and a low fill time ratio (FTR) of about 0.05, creating a feast/famine condition similar to a plug-flow ASP. The low sludge yield of 0.33 kgSS x kgBOD(-1) is a result of a long sludge retention time (SRT) of about 200 days, which enables aerobic sludge digestion in the SBRs.


Subject(s)
Bioreactors , Sewage/chemistry , Waste Disposal, Fluid/methods , Bacteria, Aerobic , Facility Design and Construction , Time Factors
SELECTION OF CITATIONS
SEARCH DETAIL
...