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Publication
Journal: Neuro-Oncology
October/10/2012
Abstract
This study investigated the prevalence and the prognostic relevance of the 2 known telomere maintenance mechanisms (TMMs), telomerase activity (TA) and alternative lengthening of telomeres (ALT), in malignant peripheral nerve sheath tumors (MPNST). In 57 specimens from 49 patients with MPNST (35 sporadic, 14 neurofibromatosis type 1-related), TA was determined using the telomeric repeat amplification protocol, and ALT was detected by assaying ALT-associated promyelocytic leukemia bodies (APB) and terminal restriction fragment (TRF) length distribution. TA or ALT (defined on the basis of APB) alone was found in 24.6% or 26.3% of the lesions, respectively, whereas 6 cases (10.5%) were TA+/ALT+. A concordance between APB and TRF results in defining the ALT status was observed in 44 of 57 cases (77.2%; P < .0001). TA was more frequently expressed in samples from patients with neurofibromatosis type 1 than in those with sporadic disease (60% vs 29.4%, P = 0.087). In the overall series, TA proved to be prognostic for 5-year disease-specific death (hazard ratio, 3.78; 95% confidence interval [CI], 1.60-8.95; P = .002), even when adjusted for the presence of neurofibromatosis type 1 (hazard ratio, 4.22; 95% CI, 1.804-9.874; P = .001) and margin status after surgery (hazard ratio, 5.78; 95% CI, 2.19-15.26; P < .001). Conversely, ALT did not significantly affect clinical outcome of MPNST using either APB expression (hazard ratio, 1.25; 95% CI 0.54-2.89; P = 0.605) or TRF distribution (hazard ratio, 0.57; 95% CI, 0.17-1.96; P = .375) as the detection approach. Our results indicate for the first time that both TMMs, TA and ALT, are present in MPNST and differentially affect patient prognosis.
Publication
Journal: Bio-protocol
February/19/2017
Abstract
Telomeres are found at the end of eukaryotic linear chromosomes, and proteins that bind to telomeres protect DNA from being recognized as double-strand breaks thus preventing end-to-end fusions (Griffith et al., 1999). However, due to the end replication problem and other factors such as oxidative damage, the limited life span of cultured cells (Hayflick limit) results in progressive shortening of these protective structures (Hayflick and Moorhead, 1961; Olovnikov, 1973). The ribonucleoprotein enzyme complex telomerase-consisting of a protein catalytic component hTERT and a functional RNA component hTR or hTERC- counteracts telomere shortening by adding telomeric repeats to the end of chromosomes in ~90% of primary human tumors and in some transiently proliferating stem-like cells (Shay and Wright, 1996; Shay and Wright, 2001). This results in continuous proliferation of cells which is a hallmark of cancer. Therefore, telomere biology has a central role in aging, cancer progression/metastasis as well as targeted cancer therapies. There are commonly used methods in telomere biology such as Telomere Restriction Fragment (TRF) (Mender and Shay, 2015b), Telomere Repeat Amplification Protocol (TRAP) and Telomere dysfunction Induced Foci (TIF) analysis (Mender and Shay, 2015a). In this detailed protocol we describe Telomere Repeat Amplification Protocol (TRAP). The TRAP assay is a popular method to determine telomerase activity in mammalian cells and tissue samples (Kim et al., 1994). The TRAP assay includes three steps: extension, amplification, and detection of telomerase products. In the extension step, telomeric repeats are added to the telomerase substrate (which is actually a non telomeric oligonucleotide, TS) by telomerase. In the amplification step, the extension products are amplified by the polymerase chain reaction (PCR) using specific primers (TS upstream primer and ACX downstream primer) and in the detection step, the presence or absence of telomerase is analyzed by electrophoresis. TSNT is, an internal standard control, amplified by TS primer. NT is its own reverse primer, which is not a substrate for telomerase. These primers are used to identify false-negative results by if the gel lacks internal control bands.
Publication
Journal: Toxicology and Applied Pharmacology
January/19/2014
Abstract
Dyslipidemia is common in patients with diabetes mellitus (DM) and is considered a risk factor for the progression of diabetic nephropathy (DN). Hyperlipidemia and hyperglycemia act synergistically to induce renal injury. The present study was designed to investigate the protective effects of tocotrienols as tocotrienol-rich fraction (TRF) extracted from palm (PO) and rice bran oils (RBO) against lipid induced nephropathy in type-2 diabetic rats and its probable molecular mechanism. Male Wistar rats (175-200 g) were divided into four groups. The first group served as diabetic control, while the second and third groups received PO-TRF and RBO-TRF, respectively by gavage over a period of sixteen weeks post-induction of diabetes. The fourth group comprised of age-matched rats that served as normal control. The effects of TRF on serum lipid profile, oxidative stress markers, expression of TGF-β, fibronectin and collagen type IV were analyzed in the kidney of diabetic rats. Treatment with PO-TRF and RBO-TRF significantly improved glycemic status, serum lipid profile and renal function in type-2 diabetic rats. In addition, TRF supplementation down-regulated the expression of TGF-β, fibronectin and collagen type IV in the kidney of diabetic rats. Transforming growth factor-β (TGF-β) plays a critical role in progression of DN, but its modulation by tocotrienols in DN remains unexplored. TRF ameliorated lipid induced nephropathy in type-2 diabetes by its hypoglycemic, hypolipidemic and antioxidant activities as well as by modulation of TGF-β to prevent increased expression of collagen type IV and fibrinogen. We finally propose a mechanism for the expression of molecular markers that are significant in the events leading to diabetic nephropathy and its modulation by tocotrienols/TRF.
Publication
Journal: Journal of Biological Chemistry
June/4/1992
Abstract
Studies of the biological chemistry of most anticancer drugs have revealed their cytotoxicity is expressed after the drugs have entered cells. It is thought that anthracycline antitumor drugs exert their cytotoxicity by entering cells, diffusing into nuclei, and inhibiting topoisomerase II and/or intercalating DNA base pairs. In order to deliver anthracyclines to transferrin (TRF) receptors on the plasma membranes of human tumor cells, we have prepared conjugates of adriamycin (ADR) with human TRF. These TRF-ADR conjugates were found to be stable at low pH and to exert more efficient cytotoxicity than free drug. By using spectrofluorometry, we found that the fluorescence of ADR within the conjugate was quenched by native DNA, demonstrating the presence of conformationally available drug to intercalate with nuclear DNA. However, fluorescence was not quenched when conjugate was reacted with viable cells, indicating that ADR did not reach the nucleus. Results of fluorescence microscopy experiments confirmed that free but not conjugated ADR reached the nuclei of viable cells, and TRF-ADR conjugates labeled with fluorescein isothiocyanate were found to initiate lateral diffusion as determined by patch and cap reactions. The involvement of TRF receptors was shown by flow cytometry experiments in which native TRF inhibited binding of fluorescein-labeled TRF-ADR conjugates. These data suggest that TRF-ADR conjugates mediate cytotoxicity by a mechanism other than intercalation with nuclear DNA. This mechanism, revealed by conjugating ADR to a TRF carrier, may not initiate complications such as cardiotoxicity and drug resistance.
Publication
Journal: Clinica Terapeutica
September/28/2011
Abstract
OBJECTIVE
Oxidative stress is caused by imbalance between the productions of reactive oxygen species (ROS) and antioxidant defense mechanisms. Palm oil antioxidants such as tocotrienol rich fraction (TRF) is known to have neuroprotective effects on neurones by acting against free radical induced neuronal cell death. This study was undertaken to elucidate the effect of TRF on oxidative DNA damage and cognitive functions in experimental rats.
METHODS
A total of 20 male Wistar rats (aged 3 months) were divided into 2 groups: (i) control group fed with distilled water and (ii) experimental group fed with TRF (200 mg/ kg body weight) for 8 months. DNA damage was determined using Comet assay. Antioxidant enzymes like superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) were assessed in the blood. The Morris Water Maze (MWM) test was used to evaluate the cognitive functions.
RESULTS
DNA damage was significantly reduced in the experimental group supplemented with TRF compared to the control group (p <0.05). In the group supplemented with TRF, the percentage of DNA damage was 2.87 ± 0.48% compared to 5.96 ± 0.43% in the control group. SOD, GPx, and CAT enzyme activities increased in experimental group. Results from MWM showed improvement in cognitive functions as determined by latency to target platform, swim path and average speed between TRF and control groups.
CONCLUSIONS
Continuous supplementation of TRF for 8 months reduced DNA damage and exhibited positive influence in spatial learning and memory.
Publication
Journal: PLoS ONE
April/7/2014
Abstract
The examination of telomere dynamics is a recent technique in ecology for assessing physiological state and age-related traits from individuals of unknown age. Telomeres shorten with age in most species and are expected to reflect physiological state, reproductive investment, and chronological age. Loss of telomere length is used as an indicator of biological aging, as this detrimental deterioration is associated with lowered survival. Lifespan dimorphism and more rapid senescence in the larger, shorter-lived sex are predicted in species with sexual size dimorphism, however, little is known about the effects of behavioral dimorphism on senescence and life history traits in species with sexual monomorphism. Here we compare telomere dynamics of thick-billed murres (Urialomvia), a species with male-biased parental care, in two ways: 1) cross-sectionally in birds of known-age (0-28 years) from one colony and 2) longitudinally in birds from four colonies. Telomere dynamics are compared using three measures: the telomere restriction fragment (TRF), a lower window of TRF (TOE), and qPCR. All showed age-related shortening of telomeres, but the TRF measure also indicated that adult female murres have shorter telomere length than adult males, consistent with sex-specific patterns of ageing. Adult males had longer telomeres than adult females on all colonies examined, but chick telomere length did not differ by sex. Additionally, inter-annual telomere changes may be related to environmental conditions; birds from a potentially low quality colony lost telomeres, while those at more hospitable colonies maintained telomere length. We conclude that sex-specific patterns of telomere loss exist in the sexually monomorphic thick-billed murre but are likely to occur between fledging and recruitment. Longer telomeres in males may be related to their homogamous sex chromosomes (ZZ) or to selection for longer life in the care-giving sex. Environmental conditions appeared to be the primary drivers of annual changes in adult birds.
Publication
Journal: European Journal of Cancer Prevention
July/29/2008
Abstract
Telomerase activity is detected in more than 90% of examined tumors but not in most normal somatic cells. Among three subunits of human telomerase, human telomerase reverse transcriptase (hTERT) is the rate-limiting component for telomerase activity. Therefore, targeting hTERT represents a promising approach for diminishing telomerase function that will probably not cause substantial side effects on telomerase negative somatic cells. To explore the effects of antisense hTERT (ahTERT) on the malignant phenotypes of human SGC-7901 gastric cancer cell line in vitro, an antisense eukaryotic expression vector of hTERT was constructed by gene recombinant technology. Telomerase activity by telomeric repeat amplification protocol-ELISA, mRNA of telomerase subunits, c-myc and bcl-2 by reverse transcript-PCR, terminal restriction fragment (TRF) by Southern blot, cell cycle distribution by flow cytometry and protein expression of hTERT, c-myc and bcl-2 by Western blot were analyzed in SGC-7901 cells before and after transfection. Cloning efficiency assay in soft agar and tumorigenesis in nude mice were also examined and evaluated in the above cells. The results demonstrated that after ahTERT transfection, the proliferation of SGC-7901 cells was significantly inhibited. Further study showed that telomerase activity, telomere length, the mRNA and protein expression of hTERT, bcl-2 and c-myc were decreased in ahTERT-transfected cells. There were, however, no obvious effects on transcription of human telomerase RNA (hTR) and human telomerase associated protein1 (TP1) in both transfected and untransfected cells. Flow cytometric analysis displayed an accumulation of G0/G1 phase and a decreasing proliferation index (PI) in ahTERT-transfected cells. Moreover, no tumorigenicity was found after subcutaneous injection of ahTERT-transfected cells in nude mice, whereas palpable tumors were observed in mice injected with control cells. Our study indicates that exogenous ahTERT can inhibit proliferation and partially reverse malignant phenotypes of SGC-7901 cells via the suppression of telomerase activity, hTERT, c-myc and bcl-2 expression. Antisense technology targeted hTERT strategy might be a potential approach for gastric cancer therapy.
Publication
Journal: Archives of Biochemistry and Biophysics
February/22/1993
Abstract
Adriamycin (ADR) was coupled to human transferrin (TRF) by using a glutaraldehyde crosslinking method. The TRF-ADR conjugates were separated by column chromatography and the molar ratio of ADR to TRF (i.e., conjugation number) for the studied conjugates was found to be 1.2. Analysis in sodium dodecyl sulfate-polyacrylamide gels demonstrated that TRF-ADR conjugates with this molar ratio had the same mobility as native TRF and contained few aggregates. The ADR remained conjugated to TRF under conditions of decreased pH known to occur in many intracellular compartments, and analysis by spectrofluorometry revealed that the conjugated ADR retained its ability to intercalate DNA. The TRF-ADR conjugates were shown by flow cytometry to preferentially bind tumor cells and cell-bound conjugates were found to be laterally mobile within plasma membranes. The binding of TRF-ADR conjugates was determined to be saturable, and competition experiments done with both radioiodinated and fluorescein-labeled TRF-ADR conjugates demonstrated dose-dependent inhibition of conjugate binding by unlabeled TRF, indicating that TRF-ADR conjugates were bound by TRF receptors. Cytotoxicity studies performed with tritiated thymidine incorporation and tetrazolium reduction assays revealed that TRF-ADR conjugates inhibited the proliferation of both K562 and HL60 cells in culture more effectively than free ADR. Such conjugates could provide a delivery system for ADR that would target the drug and possibly diminish its dose-associated complications.
Publication
Journal: Pflugers Archiv European Journal of Physiology
July/25/2017
Abstract
The cellular lifetime includes stages such as differentiation, proliferation, division, senescence and apoptosis. These stages are driven by a strictly ordered process of transcription dynamics. Molecular disruption to RNA polymerase assembly, chromatin remodelling and transcription factor binding through to RNA editing, splicing, post-transcriptional regulation and ribosome scanning can result in significant costs arising from genome instability. Cancer development is one example of when such disruption takes place. RNA silencing is a term used to describe the effects of post-transcriptional gene silencing mediated by a diverse set of small RNA molecules. Small RNAs are crucial for regulating gene expression and microguarding genome integrity. RNA silencing studies predominantly focus on small RNAs such as microRNAs, short-interfering RNAs and piwi-interacting RNAs. We describe an emerging renewal of interest in a 'larger' small RNA, the transfer RNA (tRNA). Precisely generated tRNA-derived small RNAs, named tRNA halves (tiRNAs) and tRNA fragments (tRFs), have been reported to be abundant with dysregulation associated with cancer. Transfection of tiRNAs inhibits protein translation by displacing eukaryotic initiation factors from messenger RNA (mRNA) and inaugurating stress granule formation. Knockdown of an overexpressed tRF inhibits cancer cell proliferation. Recovery of lacking tRFs prevents cancer metastasis. The dual oncogenic and tumour-suppressive role is typical of functional small RNAs. We review recent reports on tiRNA and tRF discovery and biogenesis, identification and analysis from next-generation sequencing data and a mechanistic animal study to demonstrate their physiological role in cancer biology. We propose tRNA-derived small RNA-mediated RNA silencing is an innate defence mechanism to prevent oncogenic translation. We expect that cancer cells are percipient to their ablated control of transcription and attempt to prevent loss of genome control through RNA silencing.
Publication
Journal: PLoS ONE
June/14/2014
Abstract
Tocotrienol-rich fraction (TRF) from palm oil is reported to possess anti-cancer and immune-enhancing effects. In this study, TRF supplementation was used as an adjuvant to enhance the anti-cancer effects of dendritic cells (DC)-based cancer vaccine in a syngeneic mouse model of breast cancer. Female BALB/c mice were inoculated with 4T1 cells in mammary pad to induce tumor. When the tumor was palpable, the mice in the experimental groups were injected subcutaneously with DC-pulsed with tumor lysate (TL) from 4T1 cells (DC+TL) once a week for three weeks and fed daily with 1 mg TRF or vehicle. Control mice received unpulsed DC and were fed with vehicle. The combined therapy of using DC+TL injections and TRF supplementation (DC+TL+TRF) inhibited (p<0.05) tumor growth and metastasis. Splenocytes from the DC+TL+TRF group cultured with mitomycin-C (MMC)-treated 4T1 cells produced higher (p<0.05) levels of IFN-γ and IL-12. The cytotoxic T-lymphocyte (CTL) assay also showed enhanced tumor-specific killing (p<0.05) by CD8(+) T-lymphocytes isolated from mice in the DC+TL+TRF group. This study shows that TRF has the potential to be used as an adjuvant to enhance effectiveness of DC-based vaccines.
Publication
Journal: Journal of Pathology
February/27/2012
Abstract
The alternative lengthening of telomeres (ALT) mechanism represents an alternative to the enzyme telomerase in the maintenance of mammalian telomeres in 25-60% of sarcomas and a minority of carcinomas (about 5-15%). ALT-positive cells are distinguished by long and heterogeneous telomere length distributions by terminal restriction fragment (TRF) Southern blotting. Another diagnostic marker of ALT is discrete nuclear co-localized signals of telomeric DNA and the promyelocytic leukaemia protein (PML), referred to as ALT-associated PML bodies (APBs). Recently, we detected smaller sized co-localized PML and telomere DNA (APB-like) bodies in endothelial cells adjacent to astrocytoma tumour cells in situ. In this study, we examined a wide variety of non-neoplastic tissues, and report that co-localized signals of PML and telomere DNA are present in endothelial, stromal, and some epithelial cells. Co-localized signals of PML and telomere DNA showed an increased frequency in non-neoplastic cells with DNA damage. These results suggest that a mechanism similar to that in ALT-positive tumours also operates in non-neoplastic cells, which may be activated by DNA damage.
Publication
Journal: BMC Infectious Diseases
June/12/2017
Abstract
While the global burden of typhoid fever has been often brought up for attention, the detailed surveillance information has only been available for the limited number of countries. As more efficacious vaccines will be available in the near future, it is essential to understand the geographically diverse patterns of typhoid risk levels and to prioritize the right populations for vaccination to effectively control the disease.
A composite index called the typhoid risk factor (TRF) index was created based on data with the Global Positioning System (GPS). Demographic and Health Surveys (DHS) and National Geographical Data Center (NGDC) satellite lights data were used for this analysis. A count model was adopted to validate the TRF index against the existing surveillance burden data. The TRF index was then re-estimated for 66 countries using the most recent data and mapped out for two geographical levels (sub-national boundary and grid-cell levels).
The TRF index which consists of drinking water sources, toilet facility types, and population density appeared to be statistically significant to explain variation in the disease burden data. The mapping analysis showed that typhoid risk levels vary not only by country but also by sub-national region. The grid-cell level analysis highlighted that the distribution of typhoid risk factors is uneven within the sub-national boundary level. Typhoid risk levels are geographically heterogeneous.
Given the insufficient number of surveillance studies, the TRF index serves as a useful tool by capturing multiple risk factors of the disease into a single indicator. This will help decision makers identify high risk areas for typhoid as well as other waterborne diseases. Further, the study outcome can guide researchers to find relevant places for future surveillance studies.
Publication
Journal: Journal of Abnormal Child Psychology
November/17/2014
Abstract
For gender dysphoric children and adolescents, the school environment may be challenging due to peer social ostracism and rejection. To date, information on the psychological functioning and the quality of peer relations in gender dysphoric children and adolescents has been studied via parental report, peer sociometric methods, and social interactions in laboratory play groups. The present study was the first cross-national investigation that assessed behavior and emotional problems and the quality of peer relations, both measured by the Teacher's Report Form (TRF), in a sample of 728 gender dysphoric patients (554 children, 174 adolescents), who were referred to specialized gender identity clinics in the Netherlands and Canada. The gender dysphoric adolescents had significantly more teacher-reported emotional and behavioral problems than the gender dysphoric children. In both countries, gender dysphoric natal boys had poorer peer relations and more internalizing than externalizing problems compared to the gender dysphoric natal girls. Furthermore, there were significant between-clinic differences: both the children and the adolescents from Canada had more emotional and behavioral problems and a poorer quality of peer relations than the children and adolescents from the Netherlands. In conclusion, gender dysphoric children and adolescents showed the same pattern of emotional and behavioral problems in both countries. The extent of behavior and emotional problems was, however, higher in Canada than in the Netherlands, which appeared, in part, an effect of a poorer quality of peer relations. Per Bronfenbrenner's (American Psychologist, 32, 513-531, 1977) ecological model of human development and well-being, we consider various interpretations of the cross-national, cross-clinic differences on TRF behavior problems at the level of the family, the peer group, and the culture at large.
Publication
Journal: Nutrients
November/26/2019
Abstract
The epidemic of lifestyle-dependent diseases and the failure of previous interventions to combat the main causes demand an alternative approach. Abdominal obesity is associated with most of these diseases and is a good target for therapeutic and preventive measures. Time-restricted feeding (TRF) offers a low-threshold, easy-to-implement lifestyle-modification concept with promising results from animal testing. Here, we describe a pilot study of TRF with abdominally obese participants (waist-to-height ratio, WHtR ≥0.5) in a general practitioner's office. Participants (n = 40, aged 49.1 ± 12.4, 31 females) were asked to restrict their daily eating time to 8-9 hours in order to prolong their overnight fasting period to 15-16 hours. Questionnaires, anthropometrics, and blood samples were used at baseline and at follow-up. After three months of TRF, participants had reached the fasting target, on average, on 85.5 ± 15.2% of all days recorded. Waist circumference (WC) was reduced by -5.3 ± 3.1cm (p < 0.001), and three participants reached a WHtR <0.5. HbA1c was diminished by -1.4 ± 3.5 mmol/mol (p = 0.003). TRF may be an easily understandable and readily adoptable lifestyle change with the potential to reduce abdominal obesity and lower the risk for cardiometabolic diseases. Further well-designed studies are necessary to investigate the applicability and usefulness of TRF for public health.
Publication
Journal: Methods in Molecular Biology
October/13/2017
Abstract
There is an increasing interest within the scientific community in identifying tRNA-derived fragments (tRFs) and elucidating the roles they play in the cell. Such endeavors can be greatly facilitated by mining the numerous datasets from many cellular contexts that exist publicly. However, the standard mapping tools cannot be used for the purpose. Several factors complicate this endeavor including: the presence of multiple identical or nearly identical isodecoders at various genomic locations; the presence of identical sequence segments that are shared by isodecoders of the same or even different anticodons; the existence of numerous partial tRNA sequences across the genome; the existence of hundreds of "lookalike" sequences that resemble true tRNAs; and others. This is generating a need for specialized tools that can mine deep sequencing data to identify and quantify tRFs. We discuss the various complicating factors and their ramifications, and how to use and run MINTmap, a tool that addresses these considerations.
Publication
Journal: Journal of Toxicology and Environmental Health - Part A
April/28/2010
Abstract
Underlying cardiovascular disease (CVD) is a risk factor for the exacerbation of air pollution health effects. Pulmonary oxidative stress, inflammation, and altered iron (Fe) homeostasis secondary to CVD may influence mammalian susceptibility to air pollutants. Rodent models of CVD are increasingly used to examine mechanisms of variation in susceptibility. Baseline cardiac and pulmonary disease was characterized in healthy normotensive Wistar Kyoto (WKY) rats, cardiovascular compromised spontaneously hypertensive rats (SHR), and spontaneously hypertensive heart failure (SHHF) rats. Blood pressure, heart rate, and breathing frequencies were measured in rats 11 to 12 wk of age, followed by necropsy at 14 to 15 wk of age. Blood pressure and heart rate were increased in SHR and SHHF relative to WKY rats (SHR>> SHHF>> WKY). Increased breathing frequency in SHHF and SHR (SHR>> SHHF>> WKY) resulted in greater minute volume relative to WKY. Bronchoalveolar lavage fluid (BALF) protein and neutrophils were higher in SHHF and SHR relative to WKY (SHHF>>) SHR>> WKY). Lung ascorbate and glutathione levels were low in SHHF rats. BALF Fe-binding capacity was decreased in SHHF relative to WKY rats and was associated with increased transferrin (Trf) and ferritin. However, lung ferritin was lower and Trf was higher in SHHF relative to WKY or SHR rats. mRNA for markers of inflammation and oxidative stress (macrophage inflammatory protein [MIP]-2, interleukin [IL]-1alpha, and heme oxygenase [HO]-1) were greater in SHHF and SHR relative to WKY rats. Trf mRNA rose in SHR but not SHHF relative to WKY rats, whereas transferrin receptors 1 and 2 mRNA was lower in SHHF rats. Four of 12 WKY rats exhibited cardiac hypertrophy despite normal blood pressure, while demonstrating some of the pulmonary complications noted earlier. This study demonstrates that SHHF rats display greater underlying pulmonary complications such as oxidative stress, inflammation, and impaired Fe homeostasis than WKY or SHR rats, which may play a role in SHHF rats' increased susceptibility to air pollution.
Publication
Journal: Journal of Immunology
September/18/1985
Abstract
Dibutyryl cAMP and IL 1 were found to stimulate antigen-specific and polyclonal antibody production when added together to cultures of highly purified B cells. We propose that IL 1 and an elevation in cytoplasmic cAMP represent minimal signal requirements for B cell activation. In contrast to its effect on B cells, dibutyryl cAMP inhibited helper T cell activity. Cyclic AMP suppressed the production of IL 2 and T cell replacing factor (TRF) by T cells and thus abrogated the ability of helper T cells to enhance SRBC-specific antibody production by B cells. Cyclic AMP did not inhibit the generation by T cells of B cell growth factor (BCGF). BCGF, not normally detected in Con A supernatant, was found in the culture supernatant of spleen cells that were stimulated with Con A in the presence of cAMP. Our findings indicate that cAMP blocks the production of an inhibitor of BCGF activity. cAMP had no effect on the production by macrophages of IL 1.
Publication
Journal: Journal of Intellectual Disability Research
May/9/2005
Abstract
BACKGROUND
Juvenile neuronal ceroid lipofuscinosis (JNCL) is one of the most common neurodegenerative disorders in childhood and adolescence. The clinical picture includes diverse and complex psychiatric symptoms that are difficult to treat. Only symptomatic treatment is available. To improve symptomatic therapy, it is important to recognize the symptoms. The purpose of this study was to identify predominant psychiatric symptoms in patients with JNCL.
METHODS
The study included 27 patients with JNCL with and without psychotropic treatment. The mean age was 15.2 (range 9-21) years. Characteristic psychiatric symptoms in this patient group were clarified by using the following standardized questionnaires filled in by parents, teachers and the patients themselves: Child Behavior Checklist (CBCL), Teacher Report Form (TRF) and Children's Depression Inventory (CDI). The symptoms were recorded for the entire study group and compared between patients with and without psychotropic treatment and between genders.
RESULTS
The patients had a large number of psychiatric symptoms according to the CBCL and TRF. The most commonly reported symptoms were social, thought, attention problems, somatic complaints and aggressive behaviour. Patients receiving psychotropic medication had more psychiatric symptoms according to the CBCL and TRF. Moreover, female patients had more problems than male patients according to the CBCL. The total psychiatric symptom score was at clinical or borderline range for psychiatric disturbance in 74% of patients. The number of depressive symptoms reported by the patients themselves was low.
CONCLUSIONS
JNCL patients suffer from a multitude of psychiatric symptoms. To improve drug choice and dosage, a thorough evaluation of these symptoms by standardized methods is needed before initiating treatment. Progress and possible adverse effects of treatment should be monitored on a regular basis.
Publication
Journal: Lung Cancer
February/25/2008
Abstract
Our previous report demonstrated good correlations between the expressions of h-TERT and its associated genes, such as c-Myc, <em>TRF</em>1 and <em>TRF</em>2. To observe the interaction between telomerase activity and expression of its associated genes in regulation of the telomere restriction fragment length (<em>TRF</em>L) in non-small cell lung cancer (NSCLC), 79 NSCLC specimens were examined. Telomerase activity, h-TERT, <em>TRF</em>1 and <em>TRF</em>2 genes expression were observed in 60.8, 66.7, 74.7, and 83.5% of the tumour tissues, respectively. The <em>TRF</em>L were shorter in both tumour tissues and telomerase positive tissues, as compared to their counterparts. The t/n-<em>TRF</em>LR (tumour-to-normal <em>TRF</em>L ratio) was also lower in telomerase positive tissues. When telomerase was negative, the t/n-<em>TRF</em>LR was lower in both <em>TRF</em>1 positive and TFR2 positive. However, when telomerase was positive, the t/n-<em>TRF</em>LR was only lower in the TFR2 positive group. When t/n-<em>TRF</em>LR level was equal to or less than 75%, the majority of the specimens became <em>TRF</em>1 and <em>TRF</em>2 positive. To explain these findings, our hypothesis is that when the <em>TRF</em> length becomes shorter during tumour progression, the tumour cells can sustain a better tolerance to shorter telomere with the help of both <em>TRF</em>1 and <em>TRF</em>2, but without immediate activation of the telomerase. However, when the <em>TRF</em> length reaches a critical level, changing the telomere shelterin by persistent expression of the <em>TRF</em>2, which in combination with telomerase activation reverses the telomere shortening.
Publication
Journal: European Child and Adolescent Psychiatry
July/12/2009
Abstract
In a community-based birth cohort from Arctic Norway, correlations between parents and teachers on child competence and behavioral problems were determined for Sami and Norwegian 11-12 year-olds, using as instruments the child behavior checklist (CBCL), teacher report form (TRF), and the impact supplement of the extended strength and difficulties questionnaire (SDQ). Parent-teacher correlations on child behavioral problems were generally high in the Norwegian group, but low in the Sami group. Cross-cultural differences in cross-informant correlations were highest regarding externalizing and attention problems. Parent-teacher correlations on total impact of child difficulties also differed between the ethnic groups. Once again, a lower correlation was found for the Sami children. The discrepancy between parents' and teachers' perception of problems that needed attention was highest for the Sami, and lowest for the Norwegians. The Sami parents reported fewer perceived difficulties and less impact of problems than did the Norwegian parents. In contrast, no ethnic differences emerged for teachers' ratings. The paper discusses how cultural norms might influence the reports of child problems. It demonstrates the importance of combining parent and teacher reports of child behavior problems in minority and indigenous children, who often live under different cultural norms in home and school contexts.
Publication
Journal: Journal of the American Academy of Child and Adolescent Psychiatry
August/1/2000
Abstract
OBJECTIVE
This study examined the behavioral problems in Chinese children of divorced parents.
METHODS
A total of 58 children of divorce and 116 gender-, age-, and school class-matched controls were ascertained from a general population sample of children aged 6 through 15 years. Parents completed the Child Behavior Checklist (CBCL), and teachers completed the Teacher's Report Form (TRF) and Conners Hyperkinesis Index.
RESULTS
Parent-reported problem scores on the CBCL total scale and each subscale, and prevalence of all CBCL syndromes except for Somatic Complaints, were significantly higher in children of divorce than in controls. Teacher-reported problem scores on the TRF total scale and Social and Attention Problems and prevalence of Attention Problems were significantly different for the 2 groups of children. Social competence was rated significantly lower in children of divorce than in controls. Discriminant function analysis showed that behavioral problems in children of divorce were characterized by aggressive behavior, withdrawal, and social problems.
CONCLUSIONS
The findings emanating from China provide the first evidence of the link between parental divorce and children's psychopathology and clarify the psychopathological dimensions in Chinese children of divorced parents.
Authors
Publication
Journal: Nucleic Acids Research
October/25/2015
Abstract
The ends of eukaryotic chromosomes need to be protected from the activation of a DNA damage response that leads the cell to replicative senescence or apoptosis. In mammals, protection is accomplished by a six-factor complex named shelterin, which organizes the terminal TTAGGG repeats in a still ill-defined structure, the telomere. The stable interaction of shelterin with telomeres mainly depends on the binding of two of its components, TRFTRFTRF proteins to telomeres occurs in a chromatin environment characterized by a very compact nucleosomal organization. In this work we show that binding of TRFTRFTRFTRFTRF proteins partly depends on the interaction with histone tails of their divergent N-terminal domains. We propose that the interplay between the histone octamer and TRF proteins plays a role in the steps leading to telomere deprotection.
Publication
Journal: Nature Communications
September/16/2020
Abstract
Time-restricted feeding (TRF) improves metabolism independent of dietary macronutrient composition or energy restriction. To elucidate mechanisms underpinning the effects of short-term TRF, we investigated skeletal muscle and serum metabolic and transcriptomic profiles from 11 men with overweight/obesity after TRF (8 h day-1) and extended feeding (EXF, 15 h day-1) in a randomised cross-over design (trial registration: ACTRN12617000165381). Here we show that muscle core clock gene expression was similar after both interventions. TRF increases the amplitude of oscillating muscle transcripts, but not muscle or serum metabolites. In muscle, TRF induces rhythmicity of several amino acid transporter genes and metabolites. In serum, lipids are the largest class of periodic metabolites, while the majority of phase-shifted metabolites are amino acid related. In conclusion, short-term TRF in overweight men affects the rhythmicity of serum and muscle metabolites and regulates the rhythmicity of genes controlling amino acid transport, without perturbing core clock gene expression.
Publication
Journal: BMC Genomics
June/29/2014
Abstract
BACKGROUND
Small non-coding RNAs (ncRNAs) are important regulators of gene expression in eukaryotes. Previously, only microRNAs (miRNAs) and piRNAs have been identified in the silkworm, Bombyx mori. Furthermore, only ncRNAs (50-500nt) of intermediate size have been systematically identified in the silkworm.
RESULTS
Here, we performed a systematic identification and analysis of small RNAs (18-50nt) associated with the Bombyx mori argonaute2 (BmAgo2) protein. Using RIP-seq, we identified various types of small ncRNAs associated with BmAGO2. These ncRNAs showed a multimodal length distribution, with three peaks at ~20nt, ~27nt and ~33nt, which included tRNA-, transposable element (TE)-, rRNA-, snoRNA- and snRNA-derived small RNAs as well as miRNAs and piRNAs. The tRNA-derived fragments (tRFs) were found at an extremely high abundance and accounted for 69.90% of the BmAgo2-associated small RNAs. Northern blotting confirmed that many tRFs were expressed or up-regulated only in the BmNPV-infected cells, implying that the tRFs play a prominent role by binding to BmAgo2 during BmNPV infection. Additional evidence suggested that there are potential cleavage sites on the D, anti-codon and TψC loops of the tRNAs. TE-derived small RNAs and piRNAs also accounted for a significant proportion of the BmAgo2-associated small RNAs, suggesting that BmAgo2 could be involved in the maintenance of genome stability by suppressing the activities of transposons guided by these small RNAs. Finally, Northern blotting was also used to confirm the Bombyx 5.8 s rRNA-derived small RNAs, demonstrating that various novel small RNAs exist in the silkworm.
CONCLUSIONS
Using an RIP-seq method in combination with Northern blotting, we identified various types of small RNAs associated with the BmAgo2 protein, including tRNA-, TE-, rRNA-, snoRNA- and snRNA-derived small RNAs as well as miRNAs and piRNAs. Our findings provide new clues for future functional studies of the role of small RNAs in insect development and evolution.
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