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Publication
Journal: Reproductive Health
March/15/2017
Abstract
BACKGROUND
Teenage pregnancy still remains high in low and middle-income countries (LMIC), as well as in high-income countries (HIC). It is a major contributor to maternal and child morbidity and mortality rates. Furthermore, it has social consequences, such as perpetuating the cycle of poverty including early school dropout by the pregnant adolescent, especially in sub-Saharan Africa (SSA). Few studies in SSA have investigated the trends in teenage pregnancy and the associated factors, while this is critical in fully understanding teenage pregnancy and for promotion of reproductive health among adolescents at large in SSA.
METHODS
To examine the trends in teenage pregnancy and to identify associations with other health risk behaviours in South Africa (SA), a total of 31 816 South African school-going adolescents between 11 to 19 years of age were interviewed in three cross-sectional surveys. Data from the first (2002, n = 10 549), second (2008, n = 10 270) and the third (2011, n = 10 997) nationally representative South African youth risk behaviour surveys (YRBS) were used for this study.
RESULTS
The overall prevalence of having ever been pregnant among the combined 3-survey sample was self-reported to be 11.0 % and stable across the three surveys. Sexual intercourse among adolescents in SA has decreased from 41.9 % in 2002 to 36.9 % in 2011. However, pregnancy among girls who ever had sex increased from 17.3 % (95 % CI: 0.16-0.19) in 2002, to 23.6 % (95 % CI: 0.21-0.26) in 2008 and decreased to 21.3 % (95 % CI: 0.19-0.23) in 2011. The odds for ever been pregnant were higher for girls who had 2 or more sexual partners (OR: 1.250, 95 % CI: 1.039-1.503), girls who ever used alcohol before sex (OR: 1.373, 95 % CI: 1.004-1.878), practised binge-drinking during the last month (OR: 0.624, 95 % CI: 0.503-0.774), and girls who used mandrax (OR: 1.968, 95 % CI: 1,243-3.117). The odds for never been pregnant were lower for those who used condoms (OR: 0.462, 95 % CI: 0.309-0.691).
CONCLUSIONS
Girls continue to become pregnant at unacceptably high rates in SA. Sexual intercourse among adolescents in SA has decreased slightly. However, among those who are sexually active pregnancy prevalence rates have increased. More over, this is in the context of high prevalence of HIV and other STI. There is a need to address adolescents' sexual and reproductive health, and several health risk behaviours, including substance use, that are associated with teenage pregnancy in SA.
Publication
Journal: Journal of the National Cancer Institute
August/10/1994
Abstract
The major known mechanisms of resistance to etoposide include altered expression of its target enzyme, topoisomerase II (Topo II), and the multidrug-resistant phenotypes encoded by the mdr1 and MRP (multidrug resistance-associated protein) genes. There is little information regarding the distribution, frequency, and origin of these mechanisms in cancer cells.
We performed fluctuation analysis experiments with the human sarcoma cell line, MES-SA, to assess 1) if selection or induction mechanisms are involved in resistance to etoposide, 2) mutation rates for cellular resistance to etoposide, and 3) the nature of the single-step selected surviving clones.
Three groups of 10 flasks were seeded with more than 2000 cells each and allowed to grow to near confluence (approximately 3 x 10(6) cells per flask). After reseeding, each group received etoposide for 1 week at a final concentration of 0.5 microM (group A), 1.0 microM (group B), and 5.0 microM (group C). Surviving colonies in each of the 30 populations were scored and individually harvested.
Mutation rates were estimated at 2.9 x 10(-6) (group A), 5.7 x 10(-7) (group B), and 1.7 x 10(-7) (group C) per cell generation. Of 61 propagated colonies, four of 26 from group A, five of 19 from group B, and none of 16 from group C were stably resistant. Analysis of variance supported the hypothesis of spontaneous mutations rather than induction, conferring etoposide resistance in groups A and B. Five of the stably resistant clones were cross-resistant to doxorubicin. Analysis by polymerase chain reaction failed to detect the expression of the multidrug-resistant gene mdr1 messenger RNA (mRNA) in any of the clones. No increase in expression of the MRP gene was observed. However, a significant decrease in both Topo II alpha and II beta mRNA (30%-70%) was found in six of seven stably resistant and six of six unstably resistant mutants.
Our study demonstrates that resistance to etoposide arises spontaneously, with most clones surviving either stochastically or through very labile mechanisms of resistance. The experimental design has derived a set of resistant mutants from a single-step selection. In those clones, decreased expression of Topo II is the predominant mechanism selected.
These findings suggest that stable resistance to etoposide chemotherapy may be acquired by selection of spontaneously arising mutants rather than induction by drug exposure. The stably resistant clones may represent descendants from a single mutational event in each population.
Publication
Journal: Zeitschrift fur Gastroenterologie
March/20/1996
Abstract
Gastroesophageal reflux (GER) may be associated with pulmonary diseases. The aim of this study was to investigate the role of GER in patients with sleep apnea syndrome (SAS). We evaluated, therefore, in patients with SAS the occurrence of GER during simultaneous apnea monitoring, and whether GER is related to the severity of SAS.
METHODS
17 consecutive patients with proven SAS were divided into two groups according to the severity of SAS: (A) apnea index>> or = 5 and < 15, n = 8; (B) apnea index>> or = 15, n = 9. All patients underwent 24 hours pH-metry in the proximal and distal esophagus and simultaneous apnea monitoring during the night.
RESULTS
There was a high occurrence of GER in patients with SAS, but no significant difference was found between the two groups with respect to reflux times at the distal or at the proximal esophageal site. Reflux episodes and apnea periods were not timely correlated. Most of the patients of both groups were obese.
CONCLUSIONS
Patients with SAS often have GER. However, there is neither a relation of GER with the severity of SAS nor a timely association between GER- and SAS-episodes. Thus, it is unlikely that there is a direct link between GER and SAS. However, there may be factors predisposing for both diseases.
Publication
Journal: Biomaterials
November/9/2014
Abstract
Cancer stem cells (CSCs) have been identified in a variety of cancers and emerged as a new target for cancer therapy. CSCs are resistant to many current cancer treatments, including chemotherapy and radiation therapy. Therefore, eradication of this cell population is a primary objective in cancer therapy. Here, we report gold nanorods (AuNRs) mediated photothermal treatment can selectively eliminate CSCs in MCF-7 breast cancer cells. It significantly reduced the aldehyde dehydrogenase positive (ALDH(+)) cells subpopulation and the mammosphere formation ability of treated cells. Also, the gene expression of stem cell markers was decreased. Cellular uptake assay revealed that polyelectrolyte conjugated AuNRs could be internalized by CSCs much more and faster than non cancer stem cells (NCSCs), which might be the main reason for the selective elimination of CSCs. We further loaded salinomycin (SA), a CSCs inhibitor with polyelectrolyte conjugated AuNRs to get a synergistic CSCs inhibition. Enhanced inhibition of CSCs was obtained by NIR light triggered drug release and hyperthermia. This CSCs-targeted thermo-chemotherapy platform provides a new combinatorial strategy for efficient inhibition of CSCs, which is promising to improve cancer treatment and may overcome the chemoresistance and recurrence of cancer.
Publication
Journal: Science of the Total Environment
July/17/2012
Abstract
The non-occupational exposure to brominated flame retardants, and other persistent organic pollutants (POPs) was studied by collecting human breast milk samples from mothers residing in Thohoyandou area, a rural district in the Limpopo Province, northern part of South Africa (SA). Of all collected samples to be analysed (n=28), those with large enough milk volumes, (n=14) were quantified for polybrominated diphenyl ethers (PBDEs) (9 congeners: BDE-28, 47, 66, 99, 100, 138, 153, 154, and 183) and hexabromocyclododecane (HBCD) on a GC equipped with dual capillary columns and dual electron-capture detectors (ECD). The levels of PBDE congeners (median sumBDE 1.3 ng/g of lipids) and of HBCD were not far from levels generally found in European studies, and this study may be the first report on the presence of PBDEs and HBCD in SA breast milk. On a congener basis, the finding of comparably high BDE-183 levels suggests a specific PBDE usage, or contamination situation in SA. Apart from BFRs, the high DDT levels found in the breast milk from this area (median and maximum sumDDT levels of about 4600 and over 20,000 ng/g of lipids, respectively; n=28) have earlier been reported. In addition, other POPs (PCBs, HCB and HCHs) were found in SA breast milk, at relatively low levels. To conclude, measurable levels of PBDEs and HBCD, and a specific BDE congener pattern, were found in breast milk from the Limpopo province, SA. A number of other POPs, including DDTs in high levels, were also present.
Publication
Journal: Biochemical and Biophysical Research Communications
February/6/2006
Abstract
Fifteen luciferase plasmid constructs driven by various promoters including cytomegalovirus (CMV), Rous sarcoma virus (RSV), human serum albumin (SA), alpha-1 antitrypsin (AAT), cytochrome P450 CYP1A2, CYP2C9, CYP2C18, CYP2D6, CYP3A4, mouse CYP2b10, human amyloid precursor protein (APP), chicken beta actin (ACT), nuclear factor kappa B (NFkappaB), and heat shock protein 70 (HS) promoters were hydrodynamically introduced into mouse hepatocytes, and the level and persistence of luciferase gene expression were examined. Eight hours post-gene transfer, the CMV and AAT promoters showed the highest activity, followed by the CYP2D6, HS, and RSV promoters which were slightly less active. The human serum albumin promoter exhibited the lowest activity among the promoters examined. The time course of gene expression showed a two-phase decline in luciferase activity with a rapid phase within the first 5-7 days and a slower decline thereafter. Results from Southern and Northern blot analyses revealed a good correlation between the decline of luciferase activity and the decrease in mRNA level, suggesting promoter silencing as the possible mechanism for the observed transient luciferase gene expression. Inclusion of EBN1 and oriP sequences of Epstein-Barr virus into the plasmid extended the period of active transcription for about one week. These results provide important information concerning the role of promoters in regulating transgene expression and for the proper design of plasmids for gene expression and gene therapy.
Publication
Journal: Journal of Lipid Research
May/20/2001
Abstract
Although replacement of dietary saturated fat with monounsaturated and polyunsaturated fatty acids (MUFA and PUFA) has been advocated for the reduction of cardiovascular disease risk, diets high in PUFA could increase low density lipoprotein (LDL) susceptibility to oxidation, potentially contributing to the pathology of atherosclerosis. To investigate this possibility, 15 postmenopausal women in a blinded crossover trial consumed 15 g of sunflower oil (SU) providing 12.3 g/day of oleate, safflower oil (SA) providing 10.5 g/day of linoleate, and fish oil (FO) providing 2.0 g/day of eicosapentaenoate (EPA) and 1.4 g/day of docosahexaenoate (DHA). During CuSO(4)-mediated oxidation, LDL was depleted of alpha-tocopherol more rapidly after FO supplementation than after supplementation with SU (P = 0.0001) and SA (P = 0.05). In LDL phospholipid and cholesteryl ester fractions, loss of n-3 PUFA was greater and loss of n-6 PUFA less after FO supplementation than after SU and SA supplementation (P < 0.05 for all), but loss of total PUFA did not differ. The lag phase for phosphatidylcholine hydroperoxide (PCOOH) formation was shorter after FO supplementation than after supplementation with SU (P = 0.0001) and SA (P = 0.006), whereas the lag phase for cholesteryl linoleate hydroperoxide (CE18:2OOH) formation was shorter after FO supplementation than after SU (P = 0.03) but not SA. In contrast, maximal rates of PCOOH and CE18:2OOH formation were lower after FO supplementation than after SA (P = 0.02 and 0.0001, respectively) and maximal concentrations of PCOOH and CE18:2OOH were lower after FO supplementation than after SA (P = 0.03 and 0.0006, respectively). Taken together, our results suggest that FO supplementation does not increase the overall oxidation of LDL ex vivo, especially when compared with SA supplementation. Consequently, health benefits related to increased fish consumption may not be offset by increased LDL oxidative susceptibility.-- Higdon, J. V., S. H. Du, Y. S. Lee, T. Wu, and R. C. Wander. Supplementation of postmenopausal women with fish oil does not increase overall oxidation of LDL ex vivo compared to dietary oils rich in oleate and linoleate. J. Lipid Res. 2001. 42: 407--418.
Publication
Journal: European Journal of Clinical Investigation
April/24/2008
Abstract
BACKGROUND
Tumour necrosis factor-alpha (TNF-alpha) converting enzyme (TACE) plays an essential role in the TNF-alpha shedding process, which could affect the outcome of acute myocardial infarction (AMI). However, it remains unclear whether it originates from the ruptured plaque or represents a systemic process. This study analysed TACE-mediated TNF-alpha shedding at the site of ruptured plaques in AMI patients and compared them with a systemic mechanism.
METHODS
The study included 60 patients with AMI who underwent percutaneous coronary intervention (PCI) and 21 patients with stable angina pectoris (SA). Local samples from the site of plaque were taken from AMI using aspiration catheter treatment. Systemic samples were also taken from the aorta in all patients with AMI and SA.
RESULTS
Systemic levels of TACE and TNF-alpha were higher in AMI patients than in SA patients. In AMI patients, these levels were higher in local samples than in systemic samples. A positive correlation was seen between local TACE and TNF-alpha levels in AMI patients. Thrombus material removed from the ruptured plaque showed immunostainings of TACE and TNF-alpha in infiltrating macrophages. By six months follow-up study, local TACE levels remained the only significant independent predictors of adverse cardiac events in AMI patients.
CONCLUSIONS
This study demonstrates that local expression of TACE is related to TNF-alpha shedding at the site of ruptured plaques in AMI patients. In addition, local TACE expression at the site of ruptured plaques may play an important role in poor outcomes in patients with AMI.
Publication
Journal: Diabetes
December/3/1975
Abstract
This report analyzes age-specific glucose (PG) and immunoassayable insulin (IRI) responses during oral glucose tolerance testing (OGTT) and examines test results in children and adolescents with OGTT abnormality using the age-appropriate control data. Controls' (n = 93) and patients' (n = 63) results were compared on the basis of statural age (SA) at the time of testing. Control tests (n = 101) showed significant positive correlation of fasting and four-hour postingestion PG with SA (p less than 0.001), but mean area under the PG curves did not vary between the SA groups (I--18.69 months, II--70-131 months, III--132+ months). The absence of differences of other sampling times permits uniform diagnostic criteria for this age group. IRI was positively correlated with SA at all testing times, and mean levels differed significantly between each SA group at every sampling time; the mean areas under the IRI curve also differed significantly between SA groups as did the mean ratios of IRI area to PG area (group I--0.2639 +/- 0.0175 S.E.M., group II--0.3864 +/- 0.0235, group III--0.6262 +/-0.0491). Patient tests (n = 110) were separated into normal (N), borderline (B), and chemical-diabetic (C) for each SA group. IRI means were above control data for each test type in each SA group at all sampling times; one fourth of these differences were significant. IRI responses also increased within each SA group from N to B to C tests. Mean IRI areas and IRI area to PG are mean ratios were higher than in controls, and this difference was greatest with the most abnormal (C) test type in each SA group. A subgroup of three patients who had low IRI responses from the outset and developed overt diabetes in one to three years was excluded from the analysis. In contrast to apparent relative insulin inefficiency with normal maturation and with chemical diabetes, they had exceptional responsiveness to their low IRI levels. Variable involvement of alpha as well as beta cells in the pathophysiology of diabetes is suggested as one explanation for these paradoxic observations. Changing receptor affinity might also be implicated.
Publication
Journal: International Journal of Nursing Studies
June/25/2013
Abstract
OBJECTIVE
To examine the practice environment, nurse reported quality of care and patient safety, and nurse workforce outcomes in medical and surgical units in private and public hospitals in South Africa (SA), and determine the association of modifiable features of the hospital such as the practice environment and patient to nurse workloads on these outcomes.
METHODS
Cross-sectional survey of nurses.
METHODS
Nurses were surveyed in medical and surgical units of 55 private hospitals and 7 public national referral hospitals in SA. A total of 1187 nurses completed the survey.
METHODS
Practice environment, patient to nurse workloads, nurse reported quality of care and patient safety, and nurse workforce outcomes including burnout, job satisfaction and intention to leave.
RESULTS
On a national level, more than half, 54.4% (634/1166) of nurses intend to leave their hospital within the next year due to job dissatisfaction and 52.3% (600/1148) rate their practice environment as poor or fair, while almost half, 45.8% (538/1174) report high levels of burnout and 44.9% (517/1152) are not confident that management will resolve patient problems. Public hospital nurses report more negative outcomes than private hospital nurses. Some 71% (320/451) of public hospital nurses rate their practice environment as poor/fair, 62.9% (281/447) are not confident management will resolve patient problems, and 59% (272/461) intend to leave their hospital within the next year due to job dissatisfaction. On a national level, more favourable practice environments are significantly associated with more positive nurse reported quality of care, and nurse workforce outcomes. This is true for private and public hospitals. Patient to nurse workloads are also significantly associated with more positive nurse reported quality of care and patient safety, and nurse workforce outcomes, but primarily in public hospitals.
CONCLUSIONS
Improving the practice environment, including patient to nurse ratios holds promise for retaining a qualified and committed nurse workforce and may benefit patients in terms of better quality care.
Publication
Journal: Nature Protocols
June/27/2007
Abstract
Substrate activity screening (SAS) is a fragment-based method for the rapid development of novel substrates and their conversion into non-peptidic inhibitors of Cys and Ser proteases. The method consists of three steps: (i) a library of N-acyl aminocoumarins with diverse, low-molecular-weight N-acyl groups is screened to identify protease substrates using a simple fluorescence-based assay; (ii) the identified N-acyl aminocoumarin substrates are optimized by rapid analog synthesis and evaluation; and (iii) the optimized substrates are converted into inhibitors by direct replacement of the aminocoumarin with known mechanism-based pharmacophores. This protocol describes a general procedure for the solid-phase synthesis of a library of N-acyl aminocoumarin substrates and the screening procedure to identify weak binding substrates.
Publication
Journal: Biology of Reproduction
November/15/1987
Abstract
The following study was undertaken to determine which hormones (luteinizing hormone, LH, and prolactin, PRL) and enzymes (cytochrome P450(17)alpha, nicotinamide adenine dinucleotide phosphate [NADPH]-cytochrome P450 reductase, 3-hydroxy-3-methylglutaryl [HMG] CoA reductase, cholesterol side-chain cleavage cytochrome P450 [P450scc], and adrenodoxin) were associated with the regulation of androgen biosynthesis by developing rat follicles and corpora lutea in vivo as well as by thecal explants maintained in culture. Immunoblots of soluble cell extracts of small antral (SA), preovulatory (PO), and luteinizing (PO + human chorionic gonadotropin [hCG], 7 h) follicles, newly formed corpora lutea (PO + hCG, 24 h), and corpora luteal isolated on Day 15 of pregnancy, demonstrated that cytochrome P450(17)alpha was low in SA follicles, selectively increased 4-fold in PO follicles, and decreased to less than 10% within 7 h after hCG. Filter hybridization assays using a 32P-labeled cytochrome P450(17)alpha cDNA probe demonstrated that changes in the content of P450(17)alpha mRNA exhibited a pattern similar to that of the enzyme. Conversely, immunoblots for other microsomal enzymes either exhibited no change (NADPH cytochrome P450 reductase) or a transient increase after the hCG surge (HMG CoA reductase), whereas the mitochondrial enzymes either increased markedly in association with luteinization (cytochrome P450scc) or were increased in a more transient manner (adrenodoxin). The LH-induced loss of cytochrome P450(17)alpha in vivo was not associated with loss of androgen biosynthesis when luteinizing theca were placed in culture in medium containing either LH or LH and PRL, suggesting that other hormones, or the presence of other cell types, are required to maintain the decrease in cytochrome P450(17)alpha in vivo. Conversely, the LH-induced increase in cytochrome P450scc in vivo was associated with the maintenance of elevated progesterone production by theca in culture, suggesting that cytochrome P450scc may be constitutively expressed in luteinized theca. Thus, thecal cell cytochrome P450(17)alpha and the regulation of its content and mRNA by LH are pivotal to the biosynthesis of androgens, the obligatory precursors for estradiol biosynthesis and the consequent development of preovulatory follicles. The molecular basis for the different effects of low versus elevated concentrations of LH on cytochrome P450(17)alpha, as well as cytochrome P450scc, remain to be determined.
Publication
Journal: Journal of Inherited Metabolic Disease
January/22/1992
Abstract
Tyrosinaemia type I is a recessively inherited disorder caused by a deficiency of fumarylacetoacetase (FAH), the last enzyme in tyrosine degradation. The presumed toxic agents are fumaryl- and maleylacetoacetate which are converted to succinylacetone (SA), a metabolite found in increased amounts in urine and plasma of the patients. The major clinical features are progressive liver damage and renal tubular defects with hypophosphataemic rickets. Renal tubular dysfunctions with secondary rickets may be lacking altogether, even in chronic patients. Hepatocellular carcinoma is a major cause of death in the chronic form. Diagnosis of the disorder is made by assay of SA in urine and serum and by determination of FAH in lymphocytes or fibroblasts. Prenatal diagnosis is performed by SA assay in amniotic fluid supernatant and FAH analysis in cultured amniotic fluid cells or chorionic villus material. Presence of a 'pseudodeficiency' gene for FAH prevents prenatal diagnosis by enzyme analysis in some families, and this gene also precludes identification of heterozygotes outside tyrosinaemia families. Immunoblot analyses show that acute patients and some chronic patients lack immunoreactive FAH protein. cDNA probes for FAH have been developed and several polymorphisms related to the FAH gene have been reported, which may allow prenatal diagnosis in families with complex genotypes. The gene for FAH has been mapped to chromosome 15 q23-q25. Liver transplantation is the ultimate treatment; most patients continue to excrete SA in urine after liver transplantation and therefore there is a possibility of kidney disease after transplantation.
Publication
Journal: Structure
March/18/2004
Abstract
Ketopantoate hydroxymethyltransferase (KPHMT) catalyzes the first committed step in the biosynthesis of pantothenate, which is a precursor to coenzyme A and is required for penicillin biosynthesis. The crystal structure of KPHMT from Mycobacterium tuberculosis was determined by the single anomalous substitution (SAS) method at 2.8 A resolution. KPHMT adopts a structure that is a variation on the (beta/alpha) barrel fold, with a metal binding site proximal to the presumed catalytic site. The protein forms a decameric complex, with subunits in opposing pentameric rings held together by a swapping of their C-terminal alpha helices. The structure reveals KPHMT's membership in a small, recently discovered group of (beta/alpha) barrel enzymes that employ domain swapping to form a variety of oligomeric assemblies. The apparent conservation of certain detailed structural characteristics suggests that KPHMT is distantly related by divergent evolution to enzymes in unrelated pathways, including isocitrate lyase and phosphoenolpyruvate mutase.
Publication
Journal: World Journal of Gastroenterology
February/18/2017
Abstract
AIM:To investigate the mechanisms of salvianolic acid A (SA-A) against liver fibrosis in vitro.METHODS:NIH/3T3 fibroblasts were cultured routinely, and incubated with 10(-4) mol/L-10(-7)mol/L SA-A for 22h. The cell viability was assayed by (3)H proline incorporation, cell proliferation by (3)H TdR incorporation, cell collagen synthetic rate was measured with (3)H proline impulse and collagenase digestion method.The total RNA was prepared from the control cells and the drug treated cells respectively, and alpha(1) I pro-collagen mRNA expression was semi-quantitatively analyzed with RT-PCR.RESULTS:10(-4)mol/L SA-A decreased cell viability and exerted some cytotoxiciy,while 10(-5)mol/L -10(-7)mol/L SA-A did not affect cell viability, but inhibited cell proliferation significantly, and 10(-6)mol/L SA-A had the best effect on cell viability among these concentrations of drugs. 10 (-5)mol/L -10(-6)mol/L SA-A inhibited intracellular collagen synthetic rate, but no significant influence on extracellular collagen secretion. Both 10(-5)mol/L and 10(-6)mol/L SA-A could decrease alpha(1)I pro-collagen mRNA expression remarkably.CONCLUSION:SA-A had potent action against liver fibrosis. It inhibited NIH/3T3 fibroblast proliferation, intracellular collagen synthetic rate and type I procollagen gene expression, which may be one of the main mechanisms of the drug.
Publication
Journal: Biological and Pharmaceutical Bulletin
February/20/2015
Abstract
Salidroside (SA), a phenylpropanoid glycoside isolated from Rhodiola rosea L., has been documented to exert a broad spectrum of pharmacological properties, including protective effects against neuronal death induced by various stresses. To provide further insights into the neuroprotective functions of SA, this study examined whether SA can attenuate cobalt chloride (CoCl2)-induced hypoxia damage and mammalian target of rapamycin (mTOR) signaling repression in PC12 differentiated cells. Differentiated PC12 cells were exposed to CoCl2 for 12 h to mimic hypoxic/ischemic conditions and treated with SA at the same time, followed by electron microscopy and analysis of cell viability, intracellular reactive oxygen species (ROS) level, hypoxia-inducible factor-1α (HIF-1α) level, and the regulated in development and DNA damage responses (REDD1)/mTOR/ p70 ribosomal S6 kinase (p70S6K) signaling pathway. Our data indicated that SA can dramatically attenuate the ultrastructural damage of mitochondria induced by CoCl2 and significantly decrease CoCl2-induced ROS production. Moreover, phosphorylated mammalian target of rapamycin (p-mTOR) was significantly reduced by CoCl2, and this inhibition was relieved by the treatment of SA in PC12 cells, as evidenced by immunoblot and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analyses. The SA effects were blocked by pretreatment of RAD001. The results indicate that SA can rescue CoCl2-induced repression of REDD1/mTOR/ p70S6K signal transduction in PC12 cells. Our data demonstrate that SA is able to attenuate CoCl2-induced hypoxia damage and mTOR signaling repression, suggesting that SA may protect brain neurons from ischemic injury through mTOR signaling, and provide new insights into the prevention and treatment of cerebral ischemic.
Publication
Journal: Toxicological Sciences
July/10/2005
Abstract
Di-(2-ethylhexyl)-phthalate (DEHP) is a widely used plasticizer and ubiquitous environmental contaminant. The potential health hazards, including teratogenicity, from exposure to DEHP may be related to the role of DEHP or its metabolites in the trans-activation of peroxisome proliferator-activated receptors (PPARs). Fetal essential fatty acid (EFA) homeostasis is controlled by directional transfer across the placenta through a highly regulated process, including PPAR activation. Using HRP-1 rat trophoblastic cells, the effects of DEHP and two of its metabolites, mono-(2-ethylhexyl)-phthalate (MEHP) and 2-ethylhexanoic acid (EHA), on the mRNA and protein expression of the three known PPAR isoforms (alpha, beta, and gamma), fatty acid transport protein 1 (FATP1), plasma membrane fatty acid binding protein (FABPpm), and the heart cytoplasmic fatty acid binding protein (HFABP) were investigated. This study also investigated the functional effects of exposure on the uptake and transport of six long chain fatty acids (LCFAs): arachidonic acid (AA), docosahexaenoic acid (DHA), linoleic acid (LA), alpha-linolenic acid (ALA), oleic acid (OA), and stearic acid (SA). In the presence of DEHP, MEHP, and EHA, the expression of PPARalpha, PPARgamma, FATP1, and HFABP were up-regulated in a dose- and time- dependent manner, while PPARbeta and FABPpm demonstrated variable expression. The uptake rates of EFAs (AA, DHA, LA, ALA) increased significantly upon exposure, and the transport of AA (omega-6) and DHA (omega-3) were directionally induced. These results suggest that DEHP, MEHP, and EHA can influence EFA transfer across HRP-1 cells, implying that these compounds may alter placental EFA homeostasis and potentially result in abnormal fetal development.
Publication
Journal: Molecular and Cellular Biology
June/1/1995
Abstract
The thyroid hormone (T3) receptor (TR) variant TR alpha 2 is abundant in brain but does not bind T3 because of its unique C terminus. The only known function of TR alpha 2, inhibition of TR-dependent transactivation, involves competition for T3 response elements. Paradoxically, in vitro-translated TR alpha 2 bound poorly to these sites. We report here that dephosphorylation of TR alpha 2 restored its DNA binding. Mutation of C-terminal serine residues to alanine (TR alpha 2-SA) was equally effective. The C terminus of TR alpha 2 was phosphorylated in a human cell line, whereas that of TR alpha 2-SA was not. Conversely, TR alpha 2-SA was a much better inhibitor of T3 action than was wild-type TR alpha 2. The dominant negative activity of TR alpha 2-SA was less than stoichiometric with TR concentration, possibly because it was unable to heterodimerize with retinoid X receptor, which enhances the binding of other TRs. Purified casein kinase II as well as a reticulocyte casein kinase II-like activity phosphorylated TR alpha 2 on serines 474 and 475. Mutation of these two residues to alanine was sufficient to restore DNA binding. Thus, DNA binding by TR alpha 2 is regulated by phosphorylation at a site distant from the DNA-binding domain. The increased dominant negative activity of a nonphosphorylatable form of TR alpha 2 suggests that phosphorylation may provide a rapid, T3-independent mechanism for cell-specific modulation of the expression of T3-responsive genes.
Publication
Journal: Journal of Applied Psychology
December/1/2004
Abstract
This research presents the inferential statistics for Cronbach's coefficient alpha on the basis of the standard statistical assumption of multivariate normality. The estimation of alpha's standard error (ASE) and confidence intervals are described, and the authors analytically and empirically investigate the effects of the components of these equations. The authors then demonstrate the superiority of this estimate compared with previous derivations of ASE in a separate Monte Carlo simulation. The authors also present a sampling error and test statistic for a test of independent sample alphas. They conclude with a recommendation that all alpha coefficients be reported in conjunction with standard error or confidence interval estimates and offer SAS and SPSS programming codes for easy implementation.
Publication
Journal: Oral Oncology
March/2/2011
Abstract
Ameloblastoma is the most common clinically significant odontogenic tumor. It is considered benign but locally invasive and associated with variable clinico-pathological behavior. Ameloblastic carcinoma is a malignant tumor having features of ameloblastoma in addition to cytologic atypia with or without metastasis. It is aggressive and associated with poor prognosis. The aim of this study was to examine which epithelial and stromal markers are predictive of histologically diagnosed ameloblastic carcinoma and can sufficiently differentiate it from solid/multicystic ameloblastoma (SA). We examined immunohistochemically Ki-67, epithelial membrane antigen (EMA), alpha-smooth muscle actin (alpha-SMA), calponin, p63 and DNA content using image (ICM) and flow cytometry (FCM) in three ameloblastic carcinomas and up to 18 SAs. The important findings were that Ki-67 labeling index was significantly higher in ameloblastic carcinoma than SA while EMA, calponin, p63, ICM and FCM did not sufficiently differentiate the two groups of lesions. Expression of alpha-SMA was consistently obtained within the epithelial island cells of ameloblastic carcinoma and not in SA, although the marker was well expressed in the stroma of both lesions. We therefore conclude that the presence of alpha-SMA within the epithelial islands is highly predictive of ameloblastic carcinoma.
Publication
Journal: Journal of Neuroimmunology
March/22/1995
Abstract
To characterize the phenotype of inflammatory cells in the central nervous system (CNS) in experimental autoimmune encephalomyelitis (EAE), Lewis rats were immunized with guinea pig myelin basic protein and frozen sections of the spinal cord with EAE were examined immunohistochemically using a panel of monoclonal antibodies against T cells and adhesion molecules. In addition, double immunostaining was performed with glial and T cells markers to examine the interaction between infiltrating T cells and reactive brain cells during the course of EAE. In the early stage of EAE, inflammatory cells first appeared in the subarachnoid space (SAS) and infiltrated the subpial region. The majority of inflammatory cells in SAS expressed TCR alpha beta and either CD4 or CD8 molecules. However, only CD4+ T cells infiltrated the parenchyma while the majority of CD8+ cells remained in SAS. A similar differential localization of T cells was observed with regard to CD45RC molecules. Inflammatory cells in SAS consisted of both CD45RC+ and CD45RC- population, while those in the parenchyma were largely CD45RC-. With regard to adhesion molecules, the leptomeninges constitutively expressed fibronectin (FN) and intercellular adhesion molecule 1 (ICAM-1). Most SAS inflammatory cells expressed very late activation antigen 4 (VLA-4) and, to lesser extent, lymphocyte function-associated antigen 1 (LFA-1) in the early stage of EAE. On the other hand, parenchymal infiltrating cells expressed LFA-1 more strongly in the peak stage. Double staining for V beta 8.2 TCR and microglia demonstrated an increase in the number of microglia together with morphological changes into rod-shape cells in the vicinity of infiltrating T cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Publication
Journal: International Journal of Psychophysiology
January/13/2005
Abstract
The associations among psychometric measures of anxiety and depression and individually adjusted electroencephalogram (EEG) spectral power measures registered in resting condition and during experimental settings were investigated in 30 males aged 18-25 years. During all stages of registration, Taylor Manifest Anxiety and Spielberger state anxiety (SA) and trait anxiety (TA) scores were positively related to alpha and negatively to delta relative power with these relations being independent of cortical site. Within-subject estimate of the strength of reciprocal relationship between alpha and delta oscillations (alpha-delta anticorrelation, or ADA) was positively related to trait anxiety and depression. Three minutes after an alarming event (unexpected loud sound), a further increase of alpha power was observed. In low-anxiety subjects, this increase was mostly associated with fast alpha (alpha 3), whereas in high-anxiety ones, it was mainly linked to slow alpha (alpha 2). SA mediated relationship between TA and EEG power, while ADA and alpha band reactivity showed trait-like features being associated with TA even after accounting for SA. These findings are interpreted as an indication of higher vigilance and higher reactivity of alpha system in anxious individuals.
Publication
Journal: Journal of Affective Disorders
April/25/2012
Abstract
BACKGROUND
Perinatal non-psychotic common mental disorders (PCMDs) are less well recognised in men than in women. However, there are adverse consequences of PCMD for men, their partners and their infants. There is a need for simple, readily administered screening tools for use in research and primary health care for men, including in low income settings. The aim of this study was to validate three scales for screening PCMDs in men in northern Vietnam.
METHODS
Translated and culturally verified versions of the Edinburgh Postnatal Depression Scale (EPDS), Zung's Self-rated Anxiety Scale (Zung SAS), and the General Health Questionnaire 12 items (GHQ-12) were validated against a gold-standard diagnostic tool, the Structured Clinical Interview for DSM IV diagnoses in a community-based sample of 231 Vietnamese men who were partners of pregnant women or women who had recently given birth. Post-hoc analyses, Receiver Operating Characteristic (ROC) analyses, and Cronbach's alpha were performed to examine the validity and internal reliability of the three scales.
RESULTS
The prevalence of PCMDs in men was 17.8% (95%CI: 13.3-22.3). The AUROC of the EPDS 76.7% (95%CI: 67.9-85.5), the Zung SAS was 77.5% (95%CI: 68.9-86.0) and the GHQ-12 was 79.2% (95%CI: 71.2-87.1). The selected cut-off point to detect clinically significant symptoms in men using the EPDS was 4/5 (Sensitivity (Se) 68.3% and specificity (Sp) 77.4%), the Zung SAS was 35/36 (Se 70.7% and Sp 79.0%) and the GHQ-12 was 0/1 (Se 75.6% and Sp 74.7%).
CONCLUSIONS
PCMDs in men are an unrecognised public health problem in northern Vietnam. Overall the cut off scores to detect clinically significant symptoms are lower than those reported in high income settings. Cut off scores on the EPDS and Zung SAS are slightly higher in men than in women in northern Vietnam, but these scales are suitable for use with men in this setting. Although not suitable to detect PCMD in women, the GHQ-12 is suitable to detect PCMD in men.
Publication
Journal: Microbiology and Immunology
July/2/2006
Abstract
We previously reported that glycopeptidolipid (GPL) isolated from Mycobacterium avium serovar 4 inhibited phagosome-lysosome (P-L) fusion when macrophages phagocytosed heat-killed Staphylococcus aureus (SA). In the present study we analyzed the underlying inhibitory mechanism of GPL coated on SA. Elimination of oligosaccharide from GPL abrogated its inhibitory activity. GPL did not inhibit P-L fusion of opsonized SA phagocytosed via complement receptors. The inhibitory activity of GPL was competitively reduced by the presence of alpha-methyl-D-mannoside and anti-mannose receptor antibody, suggesting that inhibition of P-L fusion by GPL is mediated through mannose receptor. Recruitment of early endosome antigen 1 and Ca2+/calmodulin kinase II in human macrophage-like THP-1 cells were significantly suppressed by GPL, indicating that GPL inhibits steps for leading to the P-L fusion.
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