A survey of chronic renal failure (CRF) in Swedish children was carried out for the period 1978-1985, using age-related cut-off levels for creatinine concentrations corresponding approximately to a glomerular filtration rate of 30 ml/min per 1.73 m2. The mean annual incidence of CRF was 6.9 and of terminal renal failure (TRF) 4.4/million children. The prevalence increased during the study period, for preterminal renal failure from 14.1 (1978) to 26.1 (1985) and for TRF from 12.4 to 16/million children. The main groups of primary renal disease were malformations (42%), hereditary disorders (27%), and glomerular diseases (14%), while pyelonephritis with vesico-ureteral reflux only made up 5%.

The cotranscriptional mRNA processing and packaging reactions that lead to the formation of export-competent messenger ribonucleoprotein particles (mRNPs) are under the surveillance of quality control steps. Aberrant mRNPs resulting from faulty events are retained in the nucleus with ensuing elimination of their mRNA component. The molecular mechanisms by which the surveillance system recognizes defective mRNPs and stimulates their destruction by the RNA degradation machinery are still not completely elucidated. Using an experimental approach in which mRNP formation in yeast is disturbed by the action of the bacterial Rho helicase, we have shown previously that the targeting of Rho-induced aberrant mRNPs is mediated by Rrp6p, which is recruited cotranscriptionally in association with Nrd1p following Rho action. Here we investigated the specific involvement in this quality control process of different cofactors associated with the nuclear RNA degradation machinery. We show that, in addition to the main hydrolytic action of the exonuclease Rrp6p, the cofactors Rrp47p, Mpp6p as well as the <em>Trf</em>-Air-Mtr4 polyadenylation (TRAMP) components <em>Trf</em>4p, <em>Trf</em>5p, and Air2p contribute significantly by stimulating the degradation process upon their cotranscriptional recruitment. <em>Trf</em>4p and <em>Trf</em>5p are apparently recruited in two distinct TRAMP complexes that both contain Air2p as component. Surprisingly, Rrp47p appears to play an important role in mutual protein stabilization with Rrp6p, which highlights a close association between the two partners. Together, our results provide an integrated view of how different cofactors of the RNA degradation machinery cooperate to target and eliminate aberrant mRNPs.

Many data pertaining to the accelerated telomere loss in cultured cells derived from Werner syndrome (WS), a representative premature aging syndrome, have been accumulated. However, there have been no definitive data on in vivo telomere shortening in WS patients. In the present study, we measured terminal restriction fragment (TRF) lengths of 10 skin samples collected from extremities of 8 WS patients aged between 30 and 61 years that had been surgically amputated because of skin ulceration, and estimated the annual telomere loss. Whereas the values of TRF length in younger WS patients (in their thirties) were within the normal range, those in older WS patients were markedly shorter relative to non‐WS controls. Regression analyses indicated that the TRF length in WS was significantly shorter than that in controls (p < 0.001). Furthermore, we found that TRF lengths in muscle adjacent to the examined epidermis were also significantly shorter than those of controls (p = 0.047). These data demonstrate for the first time that in vivo telomere loss is accelerated in systemic organs of WS patients, suggesting that abnormal telomere erosion is one of the major causes of early onset of age‐related symptoms and a predisposition to sarcoma and carcinoma in WS.

BACKGROUND

Females having a longer telomere and lifespan than males have been documented in many animals. Such linkage however has never been reported in fish. Progressive shortening of telomere length is an important aging mechanism. Mounting in vitro evidence has shown that telomere shortening beyond a critical length triggered replicative senescence or cell death. Estrogen has been postulated as a key factor contributing to maintenance of telomere and sex-dependent longevity in animals. This postulation remains unproven due to the lack of a suitable animal system for testing. Here, we introduce a teleost model, the Japanese medaka Oryzias latipes, which shows promise for research into the molecular mechanism(s) controlling sex difference in aging.

RESULTS

Using the medaka, we demonstrate for the first time in teleost that (i) sex differences (female>> male) in telomere length and longevity also exist in fish, and (ii) a natural, 'menopause'-like decline of plasma estrogen was evident in females during aging. Estrogen levels significantly correlated with telomerase activity as well as telomere length in female organs (not in males), suggesting estrogen could modulate telomere length via telomerase activation in a sex -specific manner. A hypothetical in vivo 'critical' terminal restriction fragment (TRF, representing telomere) length of approximately 4 kb was deduced in medaka liver for prediction of organismal mortality, which is highly comparable with that for human cells. An age conversion model was also established to enable age translation between medaka (in months) and human (in years). These novel tools are useful for future research on comparative biology of aging using medaka.

CONCLUSIONS

The striking similarity in estrogen profile between aging female O. latipes and women enables studying the influence of "postmenopausal" decline of estrogen on telomere and longevity without the need of invasive ovariectomy. Medaka fish is advantageous for studying the direct effect of increased estrogen on telomere length and longevity without the breast cancer complications reported in rodents. The findings strongly support the notion that O. latipes is a unique non-mammalian model for validation of estrogenic influence on telomere and longevity in vertebrates. This laboratory model fish is of potential significance for deciphering the ostensibly conserved mechanism(s) of sex-associated longevity in vertebrates.

BACKGROUND

Tocotrienols (T3) and tocopherols (T), both members of the natural vitamin E family have unique biological functions in humans. T3 are detected in circulating human plasma and lipoproteins, although at concentrations significantly lower than α-tocopherol (α-T). T3, especially α-T3 is known to be neuropotective at nanomolar concentrations and this study evaluated the postprandial fate of T3 and α-T in plasma and lipoproteins.

METHODS

Ten healthy volunteers (5 males and 5 females) were administered a single dose of vitamin E [526 mg palm tocotrienol-rich fraction (TRF) or 537 mg α-T] after 7-d pre-conditioning on a T3-free diet. Blood was sampled at baseline (fasted) and 2, 4, 5, 6, 8, and 24 h after supplementation. Concentrations of T and T3 isomers in plasma, triacylglycerol-rich particles (TRP), LDL, and HDL were measured at each postprandial interval.

RESULTS

After TRF supplementation, plasma α-T3 and γ-T3 peaked at 5 h (α-T3: 4.74 ± 1.69 μM; γ-T3: 2.73 ± 1.27 μM). δ-T3 peaked earlier at 4 h (0.53 ± 0.25 μM). In contrast, α-T peaked at 6 h (30.13 ± 2.91 μM) and 8 h (37.80 ± 3.59 μM) following supplementation with TRF and α-T, respectively. α-T was the major vitamin E isomer detected in plasma, TRP, LDL, and HDL even after supplementation with TRF (composed of 70% T3). No T3 were detected during fasted states. T3 are detected postprandially only after TRF supplementation and concentrations were significantly lower than α-T.

CONCLUSIONS

Bio-discrimination between vitamin E isomers in humans reduces the rate of T3 absorption and affects their incorporation into lipoproteins. Although low absorption of T3 into circulation may impact some of their physiological functions in humans, T3 have biological functions well below concentration noted in this study.

OBJECTIVE

The length of DNA telomeres is an important parameter of the proliferative potential of tissues. A recent study has reported abnormally short telomeres in skeletal muscle of athletes with exercise-associated fatigue. This important report raises the question of whether long-term practice of sports might have deleterious effects on muscle telomeres. Therefore, we aimed to compare telomere length of a group of power lifters (PL; N = 7) who trained for 8 +/- 3 yr against that of a group of healthy, active subjects (C; N = 7) with no history of strength training.

METHODS

Muscle biopsies were taken from the vastus lateralis, and the mean and minimum telomeric restriction fragments (TRF) (telomere length) were determined, using the Southern blot protocol previously used for the analysis of skeletal muscle.

RESULTS

There was no abnormal shortening of telomeres in PL. On the contrary, the mean (P = 0.07) and the minimum (P = 0.09) TRF lengths in PL tended to be higher than in C. In PL, the minimum TRF length was inversely correlated to the individual records in squat (r = -0.86; P = 0.01) and deadlift (r = -0.88; P = 0.01).

CONCLUSIONS

These results show for the first time that long-term training is not associated with an abnormal shortening of skeletal muscle telomere length. Although the minimum telomere length in PL remains within normal physiological ranges, a heavier load put on the muscles means a shorter minimum TRF length in skeletal muscle.

Achenbach's Child Behavior Checklist (CBCL) and Teachers' Report Form (TRF) were administered to 6-12 year old school children comprising a large random community sample (n = 1200) drawn from the whole of Greece. These are the first data on the TRF in Greece and the first nation-wide data on the CBCL. Appropriate cutoff points for the behavioral problems and competence scales of both questionnaires were obtained for boys and girls. These were considerably higher than USA cutoffs for the CBCL but not for the TRF. Analysis of scores in relation to degree of urbanization showed that it was not necessary to define different cutoffs in different strata. Parents' and teachers' ratings of the same child were most highly correlated for Externalizing and Aggressive behavior for boys and for Attention problems for both sexes.

Posttranscriptional modifications in transfer RNA (tRNA) are often critical for normal development because they adapt protein synthesis rates to a dynamically changing microenvironment. However, the precise cellular mechanisms linking the extrinsic stimulus to the intrinsic RNA modification pathways remain largely unclear. Here, we identified the cytosine-5 RNA methyltransferase NSUN2 as a sensor for external stress stimuli. Exposure to oxidative stress efficiently repressed NSUN2, causing a reduction of methylation at specific tRNA sites. Using metabolic profiling, we showed that loss of tRNA methylation captured cells in a distinct catabolic state. Mechanistically, loss of NSUN2 altered the biogenesis of tRNA-derived noncoding fragments (tRFs) in response to stress, leading to impaired regulation of protein synthesis. The intracellular accumulation of a specific subset of tRFs correlated with the dynamic repression of global protein synthesis. Finally, NSUN2-driven RNA methylation was functionally required to adapt cell cycle progression to the early stress response. In summary, we revealed that changes in tRNA methylation profiles were sufficient to specify cellular metabolic states and efficiently adapt protein synthesis rates to cell stress.

Exosomes are a distinct population of extracellular vesicles of endocytic origin with a protein repertoire similar to the parent cell. Although tumour-derived exosomes harbour immunosuppressive characteristics, they also carry tumour antigens and thus potentially contribute to immune activation. The aim of this study was to examine the impact of prostate cancer exosomes on tumour antigen cross-presentation. DU145 cells, transduced with shRNA to knockdown Rab27a (DU145KD) that inhibits exosome secretion, triggered significantly stronger tumour-antigen-specific T cell responses when loaded onto dendritic cells (DC) than control DU145 cells. Enhanced T cell response was prevented by adding purified exogenous DU145 exosomes to DU145KD cells, demonstrating that the dominant effect of tumour exosomes is immunosuppression and not antigen delivery. CD8+ T cell responses were impaired via exosomal regulation of DC function; exosomes triggered the expression of CD73, an ecto-5-nucleotidase responsible for AMP to adenosine hydrolysis, on DC. CD73 induction on DC that constitutively express CD39 resulted in an ATP-dependent inhibition of TNFα- and IL-12-production. We identified exosomal prostaglandin E2 (PGE2) as a potential driver of CD73 induction, as inhibition of PGE2 receptors significantly reduced exosome-dependent CD73 induction. The results reveal a hitherto unknown suppression of DC function via exosomal PGE2, adding a new element to tumour exosome-immune cell cross-talk. Abbreviations: AMP: adenosine monophosphate; ATP: adenosine triphosphate; BLCL: B lymphoblastoid cell line; CME: exosomes enriched from cell line conditioned media; DC: dendritic cell; DMSO: dimethyl-sulfoxide; DU145C: DU145 cells with irrelevant knockdown control; DU145KD: DU145 cells with Rab27a knockdown; ELISA: enzyme-linked immunosorbent assay; FBS: fetal bovine serum; GM-CSF: granulocyte-monocyte colony stimulating factor; HLA: human lymphocyte antigen; IL: interleukin; LPS: lipopolysaccharide; mfi: mean fluorescence intensity; PBMC: peripheral blood mononuclear cells; PBS: phosphate buffer solution; PGE2: prostaglandin E2; TRF: time-resolved fluorescence.

BACKGROUND

Although a variety of non-invasive methods for measuring cardiovascular (CV) risk (such as carotid intima media thickness, pulse wave velocity (PWV), coronary artery and aortic calcification scores (measured either by CT scan or X-ray) and the ankle brachial index (ABI)) have been evaluated separately in chronic kidney disease (CKD) cohorts, few studies have evaluated these methods simultaneously. Here, we looked at whether the addition of non-invasive methods to traditional risk factors (TRFs) improves prediction of the CV risk in patients at different CKD stages.

METHODS

We performed a prospective, observational study of the relationship between the outputs of non-invasive measurement methods on one hand and mortality and CV outcomes in 143 patients at different CKD stages on the other. During the follow-up period, 44 patients died and 30 CV events were recorded. We used Cox models to calculate the relative risk for outcomes. To assess the putative clinical value of each method, we also determined the categorical net reclassification improvement (NRI) and the integrated discrimination improvement.

RESULTS

Vascular calcification, PWV and ABI predicted all-cause mortality and CV events in univariate analyses. However, after adjustment for TRFs, only aortic and coronary artery calcification scores were found to be significant, independent variables. Moreover, the addition of coronary artery calcification scores to TRFs improved the specificity of prediction by 20%.

CONCLUSIONS

The addition of vascular calcification scores (especially the coronary artery calcification score) to TRFs appears to improve CV risk assessment in a CKD population.

In a previous study, we showed that telomerase activity (TA) and human telomerase reverse transcriptase (hTERT) mRNA expression were undetectable in benign mesenchymal lesions and low-grade soft tissue sarcomas (STSs), but detectable in about 50% of intermediate-/high-grade STSs. We wondered if this lack of TA or hTERT mRNA expression could be related to the tumor sample examined and if there was a relationship between the former 2 parameters and telomere length. Two separate tumor samples from 37 STSs were examined for telomerase activity, using the telomerase repeat amplification protocol (TRAP) assay and for hTERT mRNA expression, using RT-PCR. Telomere length was determined in each tumor sample, using the terminal restriction fragments (TRF) technique. Significant variations in telomere length, TA and hTERT mRNA expression between 2 samples of the same tumor were observed in 27%, 11% and 27% of STSs, respectively. Telomere length did not correlate with TA or hTERT mRNA expression. Despite great intratumoral heterogeneity in telomere length, short and long telomeres were more often seen in the low/intermediate-grade and high-grade STS categories, respectively. Few STSs that showed a TRF pattern suggestive of alternative lengthening of telomeres (ALT) may contain ALT subpopulations.

Transfer RNAs (tRNAs) are small non-coding RNAs with lengths of approximately 70-100 nt. They are directly involved in protein synthesis by carrying amino acids to the ribosome. In this sense, tRNAs are key molecules that connect the RNA world and the protein world. Thus, study of the evolution of tRNA molecules may reveal the processes that led to the establishment of the central dogma: genetic information flows from DNA to RNA to protein. Thanks to the development of DNA sequencers in this century, we have determined a huge number of nucleotide sequences from complete genomes as well as from transcriptomes in many species. Recent analyses of these large data sets have shown that particular tRNA genes, especially in Archaea, are disrupted in unique ways: some tRNA genes contain multiple introns and some are split genes. Even tRNA molecules themselves are fragmented post-transcriptionally in many species. These fragmented small RNAs are known as tRNA-derived fragments (tRFs). In this review, I summarize the progress of research into the disrupted tRNA genes and the tRFs, and propose a possible model for the molecular evolution of tRNAs based on the concept of the combination of fragmented tRNA halves.

tRFs and tiRNAs are two new classes of regulatory non-coding small RNAs that are derived from the cleavage of pre-existing tRNAs. tRFs are 18-22 nt long and are classified into the tRF-5, tRF-3, and tRF-1 series. Here, we discuss in detail the regulatory roles of tRFs in translation, viral infections, and carcinogenesis. Moreover, we have reviewed the association of tRFs with Argonaute proteins, including their potential to function as miRNAs. Interestingly, few miRNAs are generated from pre-existing tRNAs. Hence, tRNAs generate similar-sized tRFs and miRNAs, leading to misannotations due to cross mapping of tRFs and tRNA-derived miRNAs during deep sequencing data analysis. Therefore, it is important to catalogue the overlapping sequences between tRNA-derived miRNAs and tRFs. We have catalogued the miRNAs that overlap with tRFs sequences in humans using miRBase. We identified 20 tRNA-derived miRNAs that share sequences with tRFs. Of the 20 miRNAs, 5 miRNAs (miR-3182, miR-4521, miR-1260a, miR-1260b, and miR-7977) showed significant prediction scores. Furthermore, we have identified a lysine degradation pathway as a common regulatory pathway for miR-1260a, miR-1260b, and miR-3182 by using DIANA-mirPath.

Ovarian cancer is a complex disease marked by tumor heterogeneity, which contributes to difficulties in diagnosis and treatment. New molecular targets and better molecular profiles defining subsets of patients are needed. tRNA fragments (<em>tRFs</em>) offer a recently identified group of noncoding RNAs that are often as abundant as microRNAs in cancer cells. Initially their presence in deep sequencing data sets was attributed to the breakdown of mature tRNAs, however, it is now clear that they are actively generated and function in multiple regulatory events. One such <em>tRF</em>, a 5' fragment of tRNA-Glu-CTC (<em>tRF</em>5-Glu), is processed from the mature tRNA-Glu and is shown in this study to be expressed in ovarian cancer cells. We confirmed that <em>tRF</em>5-Glu binds directly to a site in the 3'UTR of the Breast Cancer Anti-Estrogen Resistance 3 (BCAR3) mRNA thereby down regulating its expression. BCAR3 has not previously been studied in ovarian cancer cells and our studies demonstrate that inhibiting BCAR3 expression suppresses ovarian cancer cell proliferation. Furthermore, mimics of <em>tRF</em>5-Glu were found to inhibit proliferation of ovarian cancer cells. In summary, BCAR3 and <em>tRF</em>5-Glu contribute to the complex tumor heterogeneity of ovarian cancer cells and may provide new targets for therapeutic intervention.

BACKGROUND

The growing field of metabolomics has opened up new opportunities for prediction of type 2 diabetes (T2D) going beyond the classical biochemistry assays.

OBJECTIVE

We aimed to identify markers from different pathways which represent early metabolic changes and test their predictive performance for T2D, as compared to the performance of traditional risk factors (TRF).

METHODS

We analyzed 2776 participants from the Erasmus Rucphen Family study from which 1571 disease free individuals were followed up to 14-years. The targeted metabolomics measurements at baseline were performed by three different platforms using either nuclear magnetic resonance spectroscopy or mass spectrometry. We selected 24 T2D markers by using Least Absolute Shrinkage and Selection operator (LASSO) regression and tested their association to incidence of disease during follow-up.

RESULTS

The 24 markers i.e. high-density, low-density and very low-density lipoprotein sub-fractions, certain triglycerides, amino acids, and small intermediate compounds predicted future T2D with an area under the curve (AUC) of 0.81. The performance of the metabolic markers compared to glucose was significantly higher among the young (age < 50 years) (0.86 vs. 0.77, p-value <0.0001), the female (0.88 vs. 0.84, p-value =0.009), and the lean (BMI < 25 kg/m2) (0.85 vs. 0.80, p-value =0.003). The full model with fasting glucose, TRFs, and metabolic markers yielded the best prediction model (AUC = 0.89).

CONCLUSIONS

Our novel prediction model increases the long-term prediction performance in combination with classical measurements, brings a higher resolution over the complexity of the lipoprotein component, increasing the specificity for individuals in the low risk group.

BACKGROUND

Most studies of depressive symptoms in children and adolescents have been conducted in Western countries. This study was designed to examine depressive symptoms and age and gender differences in children and adolescents in China.

METHODS

Participants consisted of two community samples of children and adolescents (n1=4858, n2=1362) in Shandong, China. Child Behavior Checklist (CBCL), Teacher Report Form (TRF) and Youth Self Report (YSR) were used to assess depressive symptoms.

RESULTS

Using American norms, the prevalence rates of depression in Chinese children and adolescents were 5.9% with self report, 0.9% with parent report, and 0.8% with teacher report. Self and teacher-reported depressive symptoms were significantly increased with age for both boys and girls. Compared with American norms, self-reported depressive scores were significantly higher in Chinese adolescents, while parent and teacher-reported scores were significantly lower in Chinese children.

CONCLUSIONS

Our study lacks clinical assessment of depressive symptoms and the study is comprised of two separate samples where parent and teacher reports and youth reports could not be compared directly.

CONCLUSIONS

The prevalence of self-reported depressive symptoms in Chinese children and adolescents are much higher than those reported by either parents or teachers. Depressive symptoms are increased with age but do not differ between boys and girls.

This study evaluated the ability of the Child Behavior Checklist and the Teacher's Report Form to identify children with autism spectrum disorders (ASD), using a sample of children with ASD (n = 458), referred children without ASD (n = 1109) and children from the general population (n = 999). A ten items ASD scale was constructed using half of the sample and the ability of this scale to discriminate between children with ASD and the other children was tested for the CBCL and the TRF separately and together in the other half of the sample. Using a cut-off score of 8 the combined CBCL/TRF ASD scale demonstrated high predictive values (NPV 95%, PPV 73%) in identifying children with ASD and children in the general population sample. This might be an acceptable percentage of false positives in general screening, considering the chance that these children might have other behavioural, emotional, and developmental problems which also need psychiatric evaluation. In the referred population, using a cut-off of 13, PPV was 49% and NPV was 85%. The high NPV indicates that in a referred population the scale is especially good at identifying children who do not need evaluation with a more ASD-specific instrument.

Culture independent molecular methods have emerged as indispensable tools for studying microbial community structure and dynamics in natural habitats, since they allow a closer look at microbial diversity that is not reflected by culturing techniques. Terminal Restriction Fragment Length Polymorphism (T-RFLP) analysis is one of the informative and widely used techniques for such studies. However, the method has a few limitations to predict microbial community structure with significant accuracy. One of the major limitations is variation in real Terminal Restriction Fragment (TRF) length and observed TRF length. In the present study we report the generation of TRF length variations using different fluorescent dyes to label the PCR primers. T-RFLP profiles generated from primers labeled with different dyes varied significantly and led to inconsistent microbial species identification. Occurrence of such variations can have serious consequences on interpretation of the T-RFLP profiles from environmental samples representing complex microbial community. Therefore, in a T-RFLP study, the primers and labeling dye system should be carefully evaluated and optimized for an individual community under investigation. Further, it would be recommended to establish a target gene library in parallel with T-RFLP analysis to facilitate the accurate prediction of microbial community structure.

Telomeres are complex end structures that confer functional integrity and positional stability to human chromosomes. Despite their critical importance, there is no clear view on telomere organization in cycling human cells and their dynamic behavior throughout the cell cycle. We investigated spatiotemporal organization of telomeres in living human ECV-304 cells stably expressing telomere binding proteins TRFTRFTRFTRFTRF protein dissociates from telomere regions, territories disintegrate and individual telomeres become faintly visible. The combination of stable cell lines, CLEM and cytometry proved essential in providing novel insights in compartment-based nuclear organization and may serve as a model approach for investigating telomere-driven genome-instability and studying long-term nuclear dynamics.

Analysis of telomere status in patients with Fanconi anaemia (FA) has previously been carried out by measurement of telomere restriction fragment (TRF) length by Southern blotting and densitometry. Results from these studies indicated that FA patients had significant reduction in telomere length compared with age-matched controls. This paper confirms and extends these findings using a direct FISH technique, which showed that 15 out of 16 FA patients had increased loss of telomere signals compared with controls. In 12 out of the 16 patients, decrease in telomere signal intensity could also be detected using a Q-FISH approach.

The hypotransferrinemic mouse (trf (hpx)) is a mutant strain exhibiting transferrin deficiency, marked anemia, hyperabsorption of iron, and elevated hepatic iron stores. We set out to investigate the relative roles of anemia and of transferrin in the malregulation of intestinal iron absorption in these animals. Transfusion of erythrocytes obtained from littermate controls increased hemoglobin levels and reduced reticulocyte counts in recipient animals. Although mucosal to carcass (59)Fe transfer was reduced, total duodenal iron uptake was not significantly affected. Iron absorption in homozygotes, in contrast to littermate controls, was not reduced by hyperoxia. Mouse transferrin injections, in the short term, increased delivery of iron to the marrow and raised hemoglobin levels. Although mucosal transfer and total iron uptake were reduced at the higher transferrin doses, total uptake was still higher than in controls. Daily injections of mouse/human transferrin for 3 weeks from weaning, normalized hemoglobin values, and markedly reduced liver iron and intestinal iron absorption values in trf (hpx) animals. When such daily-injected mice were left for a week to allow transferrin clearance, iron absorption values were significantly enhanced; hemoglobin or hepatic iron levels were, however, not significantly altered. These data indicate that hyperabsorption of iron in trf (hpx) mice is not solely because of the anemia; transferrin levels per se do affect iron absorption, possibly via a direct effect on the intestinal mucosa.

BACKGROUND

With the increasing number of immigrants worldwide, it is essential to have insight into the factors associated with internalizing problems in immigrant youth. However, little research on this subject has been conducted. The aim of the current study is to contribute to the knowledge in this field.

METHODS

Data were obtained from the general population of 11- to 18-year-old Moroccan immigrant adolescents in The Netherlands. Using the Child Behavior Checklist (CBCL), Youth Self-Report (YSR), and Teacher's Report Form (TRF), 415 parent, 376 self-, and 238 teacher reports were available for analysis.

RESULTS

The data showed relations between internalizing problems and several child (externalizing and chronic health problems), proximal family (paternal and maternal support and parent-child conflict), contextual family (conflicts between parents about parenting and total number of life-events), school/peer (being bored), and migration variables (adolescent's perceived discrimination). Moreover, a modest relation was found between internalizing problems and parental psychopathology. Few associations occurred with the global family factor (e.g., family educational level). Several relations between the predictors and YSR internalizing proved to be gender-specific.

CONCLUSIONS

Our results suggested that the child, school/peer, and proximal family factors are the most important in predicting the development of internalizing problems in Moroccan immigrant adolescents. The impact of the migration factor was small.

TBP is an essential factor for eukaryotic transcription. In this study, we identified a human cDNA encoding 21-kDa TBP-like protein (TLP). The TLP ORF, carrying 186 amino acids, covered the entire 180 amino acids of the C-terminal conserved domain of human TBP with 39% identity and 76% similarity. FISH determined that human tlp gene was located at chromosome 6 region q22.1-22.3. Northern blot analysis demonstrated that TLP mRNAs were expressed in various human tissues ubiquitously. We found that the TLP proteins exist in multiple mammalian cells and chicken cells. Although the Drosophila TBP-related factor (TRF) is a neurogenesis-related transcription factor, expression of TLP was nearly constant throughout the neural differentiation of P19 cells. Unlike TRF, TLP did not bind to the TATA-box nor direct transcription initiation in vitro. Similarity between TRF and TLP was considerably lower (35 in alignment score) than that between Drosophila TBP and human TBP (88 in alignment score). Multiple amino acids critical for the TBP function were deleted or substituted in TLP. We suggest that TLP is not a bona fide vertebrate counterpart nor a direct descendant of TRF.