Determinants of Physical Activity and Screen Time Trajectories in 7th to 9th Grade Adolescents-A Longitudinal Study

Physical activity (PA) in youth tends to decline with increasing age, while sedentary behaviour including screen time (ST) increases. There are adolescents, however, whose PA and ST do not follow this pattern. The aim of this study is (i) to examine trajectories in PA and ST from grade 7-9 among students in Berlin, and (ii) to investigate the relationship of these trajectories with individual factors and school type. For the present analyses, changes in students' PA and ST across three time points from 7th to 9th grade were assessed via self-report questionnaires. Positive and negative trajectories were defined for both PA (positive: increasing or consistently high, negative: decreasing or consistently low) and ST (vice versa). Multivariable logistic regression analyses were performed to identify possible predictors of PA and ST trajectories. In total, 2122 students were included (50.2% girls, mean age 12.5 (standard deviation 0.7) years). Compared to grade 7, less students of grade 9 fulfilled PA and ST recommendations (PA: 9.4% vs. 13.2%; ST: 19.4% vs. 25.0%). The positive PA trajectory included 44% of all students (63% boys), while the positive ST trajectory included 21% of all students (30% boys). Being a boy was significantly associated with a positive PA trajectory, while being a girl, having a high socioeconomic status, and attending a high school, were significantly associated with a positive ST trajectory. Different PA and ST trajectories among adolescents should be taken into account when implementing prevention programs for this target group.

Association of individual and neighbourhood socioeconomic status with physical activity and screen time in seventh-grade boys and girls in Berlin, Germany: a cross-sectional study

OBJECTIVES

Few studies have explored the impact of neighbourhood socioeconomic status (SES) on health behaviours in youths in Germany. Our aim was to investigate the association of individual and neighbourhood SES with physical activity (PA) and screen time (ST) in students aged 12-13 years in Berlin.

DESIGN

Cross-sectional study.

SETTING

Secondary schools (high schools and integrated secondary schools) in Berlin, Germany.

PARTICIPANTS

A total of 2586 students aged 12-13 years (seventh grade).

MAIN OUTCOME MEASURES

Sociodemographics, anthropometric data and health behaviours were assessed by self-report during classes. Primary outcome was the association of individual and neighbourhood SES with meeting daily PA and exceeding daily ST recommendations. Students' characteristics were described with means or percentages. Comparisons were performed using generalised linear mixed model yielding ORs with 95% CIs.

RESULTS

Mean (±SD) age was 12.5±0.5 years, 50.5% were girls and 34.1% had a migrant background. When adjusting for individual covariates, associations of low versus high individual SES were 0.85 (0.48; 1.52) for PA and 2.08 (1.26; 3.43) for ST. Associations of low versus high neighbourhood SES were 1.76 (1.12; 2.75) for PA and 1.54 (1.10; 2.17) for ST. After additional adjustment for school type and school neighbourhood SES, associations comparing low versus high individual and neighbourhood SES were attenuated for PA (individual SES 0.74 (0.41; 1.33) and neighbourhood SES 1.51 (0.93; 2.46)) and ST (individual SES 1.88 (1.12; 3.14) and neighbourhood SES 1.40(0.98; 2.00).

CONCLUSIONS

Lower individual and neighbourhood SES were associated with higher ST. Lower neighbourhood but not individual SES was associated with higher PA. After consideration of school type and school neighbourhood SES associations were attenuated and became insignificant for the relationship between neighbourhood SES, PA and ST. Further research is warranted to unravel the complex relationships between individual SES, neighbourhood SES and school environment to develop more targeted health promotion strategies in the future.

Effects of electroconvulsive therapy on amygdala function in major depression - a longitudinal functional magnetic resonance imaging study

BACKGROUND

Electroconvulsive therapy (ECT) is one of the most effective treatments for severe depression. However, little is known regarding brain functional processes mediating ECT effects.

METHOD

In a non-randomized prospective study, functional magnetic resonance imaging data during the automatic processing of subliminally presented emotional faces were obtained twice, about 6 weeks apart, in patients with major depressive disorder (MDD) before and after treatment with ECT (ECT, n = 24). Additionally, a control sample of MDD patients treated solely with pharmacotherapy (MED, n = 23) and a healthy control sample (HC, n = 22) were obtained.

RESULTS

Before therapy, both patient groups equally showed elevated amygdala reactivity to sad faces compared with HC. After treatment, a decrease in amygdala activity to negative stimuli was discerned in both patient samples indicating a normalization of amygdala function, suggesting mechanisms potentially unspecific for ECT. Moreover, a decrease in amygdala activity to sad faces was associated with symptomatic improvements in the ECT sample (r spearman = -0.48, p = 0.044), and by tendency also for the MED sample (r spearman = -0.38, p = 0.098). However, we did not find any significant association between pre-treatment amygdala function to emotional stimuli and individual symptom improvement, neither for the ECT sample, nor for the MED sample.

CONCLUSIONS

In sum, the present study provides first results regarding functional changes in emotion processing due to ECT treatment using a longitudinal design, thus validating and extending our knowledge gained from previous treatment studies. A limitation was that ECT patients received concurrent medication treatment.

Long-term effectiveness of a combined student-parent and a student-only smoking prevention intervention among 7th grade school children in Berlin, Germany

BACKGROUND AND AIMS

In Germany, the smoking prevalence among adolescents is among the highest in Europe. Our aim was to evaluate the long-term effectiveness of a combined student-parent and a student-only smoking prevention programme to reduce the smoking prevalence among 7th grade students in Berlin.

DESIGN

Three-armed cluster-randomized controlled trial (RCT). Schools as cluster units were randomized into (i) student intervention, (ii) combined student-parent intervention or (iii) control group, with follow-up after 12 and 24 months.

SETTING

High schools and integrated secondary schools in Berlin, Germany.

PARTICIPANTS

Seventh grade students aged 11-16 years. We included 47 schools, 161 classes and 2801 students [50.1% girls, mean age ± standard deviation (SD) = 13.0 ± 0.6 years].

MEASUREMENTS

The primary outcome was self-reported regular smoking (at least one cigarette per day) after 24 months (point prevalence). Further self-reported outcomes were other smoking behaviours as well as parental rules and attitudes towards smoking. Comparisons were calculated as odds ratios (OR) with 95% confidence intervals (CI).

FINDINGS

At baseline, 2.3% of the students reported that they smoked regularly. After 24 months, 7.8% and 7.0% were regular smokers in the student-only intervention and the student-parent intervention, respectively, compared with 10.1% in the control group. The OR for being a regular smoker was 0.81 (0.34-1.92) for the student-parent intervention versus control, 0.95 (CI = 0.41-2.22) for the student-only intervention versus control and 0.85 (0.38-1.89) for student-parent intervention versus student-only intervention.

CONCLUSION

A combined student-parent smoking prevention intervention delivered via secondary schools in Berlin, Germany did not result in a statistically significant reduction in regular smoking compared with a control group or a student-only intervention. The student-only intervention did not result in a significant reduction in regular smoking compared with the control group.

TNF receptors 1 and 2 exert distinct region-specific effects on striatal and hippocampal grey matter volumes (VBM) in healthy adults

Tumour necrosis factor alpha (TNFα) has been implicated in the pathophysiology of neurodegenerative and neuropsychiatric disease, with research highlighting a role for TNFα in hippocampal and striatal regulation. TNFα signals are primarily transduced by TNF receptors 1 and 2 (TNFR1 and TNFR2), encoded by TNFRSF1A and TNFRSF1B, which exert opposing effects on cell survival (TNFR1, neurodegenerative; TNFR2, neuroprotective). We therefore sought to explore the respective roles of TNFR1 and TNFR2 in the regulation of hippocampal and striatal morphology in an imaging genetics study. Voxel-based morphometry was used to analyse the associations between TNFRSF1A (rs4149576 and rs4149577) and TNFRSF1B (rs1061624) genotypes and grey matter structure. The final samples comprised a total of 505 subjects (mean age = 33.29, SD = 11.55 years; 285 females and 220 males) for morphometric analyses of rs1061624 and rs4149576, and 493 subjects for rs4149577 (mean age = 33.20, SD = 11.56 years; 281 females and 212 males). Analyses of TNFRSF1A single nucleotide polymorphisms (SNPs) rs4149576 and rs4149577 showed highly significant genotypic associations with striatal volume but not the hippocampus. Specifically, for rs4149576, G homozygotes were associated with reduced caudate nucleus volumes relative to A homozygotes and heterozygotes, whereas for rs4149577, reduced caudate volumes were observed in C homozygotes relative to T homozygotes and heterozygotes. Analysis of the TNFRSF1B SNP rs1061624 yielded a significant association with hippocampal but not with striatal volume, whereby G homozygotes were associated with increased volumes relative to A homozygotes and heterozygotes. Our findings indicate a role for TNFR1 in regulating striatal but not hippocampal morphology, as well as a complementary role for TNFR2 in hippocampal but not in striatal morphology.

[Long-term-management of organ transplant recipients]

Due to advances in immunosuppressive therapy and surgical techniques, survival rates after solid organ transplantation have constantly improved over the last decades. In long-term care after transplantation, physicians need to focus as much on diagnosis and treatment of allograft-related complications as they should consider comorbidities and evaluate risk-factors and adverse events of immunosuppressive agents to prevent secondary diseases. In particular, cardiovascular and metabolic diseases, malignancy and infection play a major role in long-term survival. Therefore, screening of organ transplant recipients in regard to these complications and adverse events is a crucial part of follow up in these patients.

Berlin evaluates school tobacco prevention - BEST prevention: study design and methodology

BACKGROUND

The hazardous health effects of smoking are established, but there remains a need to evaluate existing smoking prevention strategies and to increase their effectiveness in adolescents. Strategies focusing on parental attitudes and rule setting have been identified as a potentially effective approach. The present manuscript describes objectives, study design and methodology of the BEST Prevention study.

METHODS/DESIGN

BEST Prevention is a three-armed cluster randomized-controlled trial among 7th grade (11-16 years) students in Berlin, Germany. Schools were enrolled between 2010 and 2011 and allocated using a centralized randomization list into 1) a student smoking prevention intervention (visit to an established interactive circuit), 2) the same intervention plus a parent intervention, and 3) a control group (visit to an established exercise and nutrition interactive circuit). Students were assessed at baseline, 12 and 24 months via self-report, as well as via carbon monoxide and cotinine in saliva at the 24 month follow-up. Statistical analyses uses multi-level regression models with cluster effects (school and class within school) based on the intention to treat population. Here we report descriptive baseline characteristics of recruited schools, and schools classes. Two schools from the control group dropped out after allocation. Hence, 47 secondary schools from all 12 districts of the city, including 161 school classes and 3023 students are participating in the study. Of those, 2801 students completed the baseline assessment.

DISCUSSION

The present manuscript provides details on the study design and methodology of a large school-based smoking prevention trial in a metropolitan area in Germany. Findings from this study will yield important insight into the long-term effectiveness of specific smoking prevention strategies, also in disadvantaged population groups.

TRIAL REGISTRATION

NCT01306552 (January 2011).

Hypoglycemic activity of dried extracts of Bauhinia forficata Link

Leaves of the pantropical genus Bauhinia (Fabaceae) are known popularly as cow's foot, due to their unique characteristic bilobed aspect. The species Bauhinia forficata (Brazilian Orchid-tree) is widely used in folk medicine as an antidiabetic. The present work investigates the hypoglycemic activity of the dried extracts of Bauhinia forficata leaves in vivo, as well as the influence of the drying and granulation processes on this activity. The fluid extract was dried to generate oven-dried (ODE), spray-dried (SDE) and wet granulation (WGE) extracts, with the aid of colloidal silicon dioxide and/or cellulose:lactose mixture. The dried extracts were characterized by spectrophotometric, chromatographic and photo microscopy image analysis. 200 mg/kg body wt., p.o. of each dried product were administered orally to male Wistar rats over 7 days old, for biomonitoring of the hypoglycemic activity profile. The effect of the extracts was studied in STZ-induced diabetic rats. After 7 days of treatment, fasting glucose was determined, and the livers were removed, dried on tissue paper, weighed, and stored at -20 degrees C to estimate hepatic glycogen. Our results show that spray-drying or oven-drying processes applied to B. forficata extracts did not significantly alter its flavonoid profile or its hypoglycemic activity. Indeed, the dried extracts of B. forficata act differently from glibenclamide. Despite the lower active content in WGE, because of the higher concentration of adjuvants, the use of the granulation process improved the manufacturing properties of the ODE, making this material more appropriate for use in tablets or capsules.

G72 and its association with major depression and neuroticism in large population-based groups from Germany

OBJECTIVE

G72 is among the most frequently replicated vulnerability genes for schizophrenia and bipolar disorder. The authors previously found identical haplotypes of markers M23 and M24 to be associated with schizophrenia, bipolar disorder, and panic disorder. Given both the well-recognized familial clustering across these disorders and recent linkage findings implicating the region harboring G72 in the etiology of major depression and panic disorder, we can hypothesize that G72 should also be involved in the etiology of major depression. Neuroticism, measuring trait anxiety, may be the endophenotypic link underlying genetic associations with G72 across diagnostic boundaries. The authors tested whether the previously observed risk haplotypes are also associated with major depression and neuroticism.

METHOD

The authors performed a standard haplotype analysis in a group of 500 major depression patients and 1,030 population-based comparison subjects. The authors also performed an exploratory analysis on 10 additional G72 markers using a novel haplotype-sharing approach. They performed a quantitative trait haplotype analysis in an independent group of 907 individuals phenotyped for neuroticism.

RESULTS

The previously identified M23-M24 risk haplotype was significantly associated with major depression and high levels of neuroticism. The haplotype-sharing analysis also implicated the same region, whereas more proximal markers showed no association with major depression.

CONCLUSIONS

This is the first study to the authors' knowledge to implicate the G72 locus in the etiology of major depression and neuroticism. The results strengthen the notion of a genetic overlap between diagnoses, commonly conceptualized as distinct entities. Neuroticism may constitute the common underlying endophenotypic link.

Development of a regional hydrologic soil model and application to the Beerze--Reusel drainage basin

The soil compartment is an important interface between the atmosphere and the subsurface hydrosphere. In this paper a conceptual approach for regional hydrologic soil modelling (RHSM) is presented, which provides two important qualities for modelling. First, the soil compartment is directly coupled to the atmosphere via the land surface and to the aquifers. Second, extremely fine (5cm vertical) resolutions of the soil system can be realized at regional scales (several hundreds of km(2)). This high-resolution modelling could be achieved by parallel computation techniques. The RHSM approach is applied to the Beerze-Reusel drainage basin, which belongs to the Meuse River basin. Moisture transport in the soil system was calculated with extremely high vertical resolution at a regional scale based on rainfall-evaporation data for the year 2000. As a result, highly resolved regional groundwater recharge pattern addressing the heterogeneity of soil systems could be determined.

Reliabilität und Validität des revidierten Beck-Depressionsinventars (BDI-II)

BACKGROUND

The Beck Depression Inventory (BDI) underwent revision in 1996 (BDI-II) with the goal of addressing DSM-IV depression criteria. The present study assessed psychometric properties of the German version of the BDI-II.

PATIENTS AND METHODS

The BDI-II was translated into German and evaluated in a series of studies with clinical and nonclinical samples.

RESULTS

The content validity of the BDI-II has improved by following DSM-IV symptom criteria. Internal consistency was satisfactorily high (alpha>or=0.84), and retest reliability exceeded r>or=0.75 in nonclinical samples. Associations with construct-related scales (depression, dysfunctional cognitive constructs) were high, while those with nonsymptomatic personality assessment (NEO-FFI) were lower. The BDI-II differentiated well between different grades of depression and was sensitive to change.

CONCLUSION

The German BDI-II demonstrates good reliability and validity in clinical and nonclinical samples. It may now replace the older version of the BDI for assessing self-rated severity of depression and course of depressed symptoms under treatment.

Copingstile im Umgang mit depressiver Stimmung

Zusammenfassung. Theoretischer Hintergrund: Der Response Styles Fragebogen (RSQ) beansprucht, Coping-Stile im Umgang mit depressiven Symptomen als Traits zu erfassen. Fragestellung: Untersuchung psychometrischer Gütekriterien der deutschen Version des RSQ. Methode: Der Fragebogen wurde an einer depressiven Patientenstichprobe nach stationärer Entlassung (n = 130) und einer Gemeindestichprobe (n = 311) faktorenanalytisch untersucht. Weitere Reliabilitäts- und Validitätsprüfungen erfolgten an Substichproben. Ergebnisse: Die Hauptkomponentenanalysen sprechen klar für eine Dreifaktorenlösung in beiden Gruppen, die Faktoren wurden mit “symptomfokussierter Rumination“, “selbstfokussierter Rumination“ und “Distraktion“ benannt. Die drei Faktoren weisen zufriedenstellende interne Konsistenzen und Retestreliabilitäten sowie plausible Muster von Zusammenhängen mit konstruktnahen Skalen und depressiver Symptombelastung auf. Symptomfokussierte Rumination und Distraktion wiesen prädiktive Validität bezüglich der Depressivität nach 5 Monaten auf. Schlussfolgerungen: Für zukünftige Forschung wird der Einsatz der faktoriell abgeleiteten RSQ-Subskalen empfohlen.

Cross-linking chitosan-Fe(III), an oral phosphate binder: studies in vitro and in vivo

The objective was to evaluate the in vitro and in vivo phosphate binding properties of cross-linked chitosan iron (III) (CH-Fe(III)-CL), a potential oral phosphate binder for treating hyperphosphatemia. At equilibrium, the in vitro phosphate binding of CH-Fe(III)-CL was 23.6 mg g(-1) for simulated gastrointestinal conditions. In hyperphosphatemic rats, CH-Fe(III)-CL was similar to iron sulfate in reducing serum phosphate by about 35%.

Preliminary evaluation of the hypoglycemic effect of some Brazilian medicinal plants

The hypoglycemic effect of five Brazilian medicinal plants (Epidendrum monsenii, Marrubium vulgare, Rheedia gardneriana, Rubus imperialis and Wedelia paludosa) was studied on alloxan-induced diabetic rats. The extract of these plants was intragastrically administered to diabetic rats. The results showed that all plants studied (except R. gardneriana) significantly lowered the blood glucose. These results suggest that these four medicinal plants could be an adjuvant agent in the treatment of diabetes mellitus.

Cloning of prokaryotic genomes in yeast artificial chromosomes: application to the population genetics of Pseudomonas aeruginosa

Yeast artificial chromosomes (YACs) can accommodate large inserts and hence should be attractive tools for intra- and interspecies comparisons of bacterial genomes. YAC libraries were constructed from size-selected partial digests of human and Pseudomonas aeruginosa PAO DNA and SpeI-restricted PAO DNA. Whereas YACs from human DNA had an average size of 350 kilobase pairs (kbp), a P. aeruginosa sequence larger than 120 kbp was absent or truncated in the eukaryotic host. Coligation occurred for YACs smaller than 40 kbp, but stable YACs with 40-120 kbp large inserts of P. aeruginosa DNA were obtained in high yield. SpeI-restricted chromosomes from 97 P. aeruginosa strains representing 47 genotypes were hybridized with stable YACs from three equidistant regions of the PAO genome. The low complexity of hybridizing bands demonstrated that the analyzed 100 kbp sequence contigs were stably maintained in most P. aeruginosa isolates from both disease and environmental habitats.

Smith/Birnstiel mapping of genome rearrangements in Pseudomonas aeruginosa

A novel application of the Smith/Birnstiel technique is presented for the analysis of intraspecies genomic diversity in small genomes. Rare-cutter total/N frequent-cutter partial restriction digestions are separated in N separate lanes by pulsed-field gel electrophoresis, blotted and hybridized with rare-cutter fragment ends as probes. The evaluation of the autoradiogram results in high-resolution restriction maps of 10-200 kbp regions. The technique was applied to the analysis of genome rearrangements in Pseudomonas aeruginosa strains. Comparison of the region encoding the tryptophan biosynthesis genes in the PAO and the IATS serotype 5 strains revealed that shared sequence characterized by almost identical restriction fingerprints was interrupted in the serotype 5 strain by small islands displaying strain-specific restriction site signatures. A multistep rearrangement in a hypervariable chromosome region downstream of the phn locus was detected in serial airway isolates from a patient with cystic fibrosis.

Cyclin ET, a new splice variant of human cyclin E with a unique expression pattern during cell cycle progression and differentiation

Cyclin E is the regulatory subunit of the cdc2-related protein kinase cdk2 and is a rate limiting factor for the entry into S phase. To date, cyclin E is the only cyclin for which alternative splicing has been described. We report here the isolation of a new splice variant of cyclin E, termed cyclin ET, which has an internal deletion of 45 amino acids compared with the full-length cyclin E protein. Even though cyclin ETcontains an intact cyclin box, it is unable to complement a triple cln mutant strain of Saccharomyces cerevisiae or to interfere with rescue by cyclin E, indicating that an intact cyclin box is functionally insufficient. The expression pattern of cyclin ET during cell cycle entry, progression and differentiation differs from that of cyclin E. Thus, ET expression precedes that of the other isoforms during the G0-->S progression; it shows a sharp peak in early G1 in cells released from a mitotic block and is strongly down-regulated in terminally differentiated myeloid cells. These observations point to different functions for cyclin ET and E and show for the first time that the alternative splicing of cyclin E is a regulated mechanism governed by the cell cycle and differentiation.

Genetic diversity of flagellins of Pseudomonas aeruginosa

Physical genome analysis of the virulence-associated fliC locus in 20 Pseudomonas aeruginosa strains by mapping and sequencing revealed groups of heterologous a-type (1164 bp; 1185 bp) and highly conserved b-type (1467 bp) flagellin genes. Whereas only two synonymous nucleotide substitutions were detected in eight b-type fliC sequences, the 12 a-type sequences exhibited 57 nucleotide substitutions, of which 39 occurred within a variable central region. Although a-type and b-type flagellins differ by 35% in their primary structure, they share strong homology in their predicted features, implying that the polymorphic proteins fold into similar structures during polymerization of the flagella.

Structure of the human TIMP-3 gene and its cell cycle-regulated promoter

The gene encoding tissue inhibitor of metalloproteinases-3 (TIMP-3) is regulated during development, mitogenic stimulation and normal cell cycle progression. The TIMP-3 gene is structurally altered or deregulated in certain diseases of the eye and in tumour cells. A detailed knowledge of the TIMP-3 gene and its regulatory elements is therefore of paramount importance to understand its role in development, cell cycle progression and disease. In this study, we present the complete structure of the human TIMP-3 gene. We show that TIMP-3 is a TATA-less gene, which initiates transcription at one major site, is composed of five exons and four introns spanning a region of approximately 30 kb, and gives rise to three distinct mRNAs, presumably due to the usage of alternative polyadenylation signals. Using somatic cell hybrids the TIMP-3 locus was mapped to chromosomal location 22q13.1 We also show that the TIMP-3 5' flanking region is sufficient to confer both high basal level expression in growing cells and cell cycle regulation in serum-stimulated cells. While the first 112 bases of the promoter, which harbour multiple Sp1 sites, were found to suffice for high basal level activity, the adjacent region spanning positions -463 and -112 was found to be a major determinant of serum inducibility. These results provide an important basis for further investigations addressing the role of TIMP-3 in physiological processes and pathological conditions.

Identification of a novel mitogen-inducible gene (mig-6): regulation during G1 progression and differentiation

We have identified a novel human gene (mig-6) that is rapidly induced upon mitogenic stimulation of quiescent fibroblasts. Serum induction is partially inhibited by protein synthesis inhibitors, indicating that mig-6 shares characteristics of both primary and secondary response genes. In contrast to most other mitogen-responsive genes, mig-6 mRNA expression is also regulated during normal cell cycle progression, showing a clear peak around mid-G1. Consistent with the regulation of mig-6 expression during the cell cycle, terminal differentiation of HL-60 cells to either granulocytic or macrophage-like cells also leads to clear changes in the levels of mig-6 mRNA. These observations suggest that the mig-6 gene represents a useful tool for the analysis of cell cycle progression and perhaps terminal differentiation. As a first step toward a functional characterization we show that the Mig-6 polypeptide is located in the cytoplasm.

Expression of the messenger RNAs for luteinizing hormone-releasing hormone (LHRH) and its receptor in human ovarian epithelial carcinoma

Recently we reported the presence of specific high affinity binding sites for luteinizing hormone-releasing hormone (LHRH) and its analogues (Kd = 1.5 or 1.7 nM) in the human epithelial ovarian cancer cell lines EFO-21 and EFO-27. The proliferation of these cell lines was inhibited by nM concentrations of a LHRH agonist. This study was performed to ascertain whether these ovarian cancer cell lines produce LHRH and whether the high affinity LHRH binding site found previously was identical to the pituitary LHRH receptor. Significant amounts of immunoreactive LHRH were found in the extracts of both the EFO-21 cell line (449 +/- 56 fmol/10(6) cells) and the EFO-27 line (409 +/- 76 fmol/10(6) cells). LHRH bioactivity of these extracts, assessed in terms of release of luteinizing hormone by rat pituitary cells, was comparable to that of authentic LHRH. EFO-21 and EFO-27 cells expressed the mRNAs for both human LHRH and human LHRH receptor as assessed by reverse transcriptase-PCR using oligonucleotide primers according to published sequences. In addition, in eight of eight biopsy samples of human epithelial ovarian cancers we detected mRNA for LHRH, six of these specimens expressed the mRNA representing the LHRH receptor. These data support the concept that human epithelial ovarian cancers might have a local system based on LHRH to regulate cell proliferation. It is still obscure at present whether LHRH produced locally has a stimulatory, inhibitory, or no impact on the proliferation of ovarian cancer cells. However, exogenous LHRH agonists seem to have clear antiproliferative activity, probably mediated through LHRH receptors. This finding might provide the base for novel approaches in the therapy of epithelial ovarian cancer.

Expression of luteinizing hormone releasing hormone and its mRNA in human endometrial cancer cell lines

Recent results have shown that specific binding sites for luteinizing hormone-releasing hormone (LHRH) are present in biopsy samples of human endometrial cancer and in the human endometrial cancer cell lines Ishikawa and HEC-1A. The proliferation of these cell lines was retarded by LHRH analogs. The present study was undertaken to determine whether these endometrial tumor cells also produce LHRH or an LHRH-like peptide which could serve as natural ligand for the LHRH binding sites. Using a specific antibody, LHRH-immunoreactivity was detected in extracts of Ishikawa (426 +/- 84 fmol/10(6) cells) and HEC-1A (368 +/- 41 fmol/10(6) cells) cells. LHRH-like bioactivity of these samples was assessed in a rat pituitary cell culture system. The release of luteinizing hormone induced by endometrial cancer cell extracts corresponded to that obtained with comparable amounts of authentic LHRH. The expression of the mRNA for LHRH could be demonstrated by reverse transcriptase - polymerase chain reaction using specific primers according to the published sequence and by subsequent Southern blot analysis. The presence of immuno- and bioactive LHRH-like factors and the demonstration of expression of the mRNA for LHRH in two human endometrial cancer cell lines supports the concept of an autocrine regulatory system based on LHRH in endometrial cancer.

A novel member of human tissue inhibitor of metalloproteinases (TIMP) gene family is regulated during G1 progression, mitogenic stimulation, differentiation, and senescence

We have identified in the human diploid fibroblast cell line WI-38 a novel serum-inducible gene, mitogen-inducible gene 5 (mig-5), of the delayed-early class, which represents a new member of the family of human tissue inhibitors of metalloproteinases (TIMPs). The deduced Mig-5 protein shares the highest degree of homology with chicken TIMP-3 (74% identity) and is more distantly related to human TIMP-1 and TIMP-2 (30-38% identity), indicating that mig-5 may represent the human homolog of chicken TIMP-3. In contrast to TIMP-1 and TIMP-2, mig-5 mRNA expression is not only induced in response to mitogenic stimulation but also is subject to cell cycle regulation in normally proliferating WI-38 fibroblasts and HL-60 myeloid cells, showing a clear peak around mid-G1. In agreement with this observation, differentiation of HL-60 cells to either granulocytic or macrophage-like cells leads to increased levels of mig-5 mRNA concomitant with a block in G1. In contrast, mig-5 expression is decreased in senescent human fibroblasts, suggesting that these cells may be blocked at a stage in G1 before or after the phase of maximum mig-5 expression. Since in contrast to the vast majority of other known mitogen-inducible genes, mig-5 expression is periodically up-regulated in G1, this gene should represent an invaluable tool for the analysis of cell cycle progression, terminal differentiation, and replicative senescence.

Lineage-specific regulation of cell cycle gene expression in differentiating myeloid cells

We have analysed the expression of 7 cyclin and cyclin-associated kinase (cdk) genes in the human myeloid cell line HL-60 at different stages of the cell cycle in non-synchronised cells and during terminal differentiation. A clear cell cycle-dependent expression was found with cyclins A (S+G2), B (G2) and E (late G1 and S), while other cell cycle genes showed only very weak (cdk2) or no periodic expression (cyclin D1, cyclin D2 and cdk4). Induction of macrophage-like differentiation by TPA or granulocytic differentiation by retinoic acid or DMSO was accompanied by a block in G1 and resulted in distinct patterns of gene expression that were lineage- and inducer-specific. These included: (i) a dramatic decrease in the expression of cyclin A, cyclin B and cdk2, and surprisingly an up-regulation of cyclin D1 in TPA-induced macrophage-like cells; (ii) a down-regulation of cyclin E in retinoic acid-induced granulocytic cells; and (iii) a decreased abundance of cyclin D1 and D2, but high levels of cyclin A, B and E RNA in DMSO-induced granulocytic cells. These observations suggest that the mechanisms leading to a differentiation-associated cell cycle arrest are lineage-specific, and that the sustained expression of cyclin and cdk genes does not interfere with the induction of terminal differentiation.

Alternative splicing of human cyclin E

Cyclin E is a regulatory subunit of the cdc2-related protein kinase cdk2, which is activated shortly before S-phase entry, thus defining it as a G1 cyclin. We report here the existence of a 43 kDa splice variant of human cyclin E, termed cyclin Es, which lacks 49 amino acids within the cyclin box compared to the known 48 kDa cyclin E. Cyclin Es is expressed at approximately 1/10 of the level of full-length cyclin E in several cell lines analysed. The two cyclin E forms differ functionally in that cyclin E, but not cyclin Es, is able to complex with cdk2, to activate the histone H1, pRb and p107 in vitro kinase activity of cdk2 and to rescue a triple CLN mutation in S. cerevisiae. Cyclin Es is the first splice variant of a cell cycle regulatory protein to be described. Our findings also indicate that the cyclin box in cyclin E mediates the interaction with cdk2.

Differential induction of ‘metabolic genes’ after mitogen stimulation and during normal cell cycle progression

Mitogenic stimulation of quiescent cells not only triggers the cell division cycle but also induces an increase in cell volume, associated with an activation of cellular metabolism. It is therefore likely that genes encoding enzymes and other proteins involved in energy metabolism and biosynthetic pathways represent a major class of mitogen-induced genes. In the present study, we investigated in the non-established human fibroblast line WI-38 the induction by mitogens of 17 genes whose products play a role in different metabolic processes. We show that these genes fall into 4 different categories, i.e. non-induced genes, immediate early (IE) primary genes, delayed early (DE) secondary genes and late genes reaching peak levels in S-phase. In addition, we have analysed the regulation of these genes during normal cell cycle progression, using HL-60 cells separated by counterflow elutriation. A clear cell cycle regulation was seen with those genes that are induced in S-phase, i.e. thymidine kinase, thymidylate synthase and dihydrofolate reductase. In addition, two DE genes showed a cell cycle dependent expression. Ornithine decarboxylase mRNA increased around mid-G1, reaching maximum levels in S/G2, while hexokinase mRNA expression was highest in early G1. In contrast, the expression of other DE and IE genes did not fluctuate during the cell cycle, a result that was confirmed with elutriated WI-38 and serum-stimulated HL-60 cells. These observations suggest that G0-->S and G1-->S transition are distinct processes, exhibiting characteristic programmes of gene regulation, and merging around S-phase entry.

Identification of serum-inducible genes: different patterns of gene regulation during G0-->S and G1-->S progression

We have identified, by differential cDNA library screening, 15 serum inducible genes in the human diploid fibroblast cell line WI-38. The genes fall into two classes that are distinguished by their dependence on protein synthesis for the induction by serum, i.e., primary and secondary genes. While 11 of these genes encode known proteins, 4 other genes have not been described to date. The former genes encode proteins of diverse functions, including the monocyte-derived neutrophil chemotactic factor (MONAP), calmodulin, tropomyosin, tenascin, collagenase, plasminogen activator inhibitor-2a, the ‘sperm-specific’ cleavage signal-1 protein, metallothionein IIa and the mitochondrial chaperonin hsp-60. Interestingly, one of the unknown genes contains a large open reading frame for a polypeptide that is highly homologous to a previously unidentified long open reading frame in the opposite strand of the gene coding for the transcription factor HTF-4. We also studied the regulation of these serum-induced genes during cell cycle progression in normally cycling WI-38 and HL-60 cells separated by counterflow elutriation as well as in serum-stimulated HL-60 cells. Our results clearly show that, in contrast to the prevailing opinion, the expression of most genes induced after mitogen stimulation is not subject to a significant regulation in normally proliferating cells. This supports the hypothesis that the progression into S from either G0 or G1 are distinct processes with specific patterns of gene expression.

Deregulation of cyclins D1 and E and suppression of cdk2 and cdk4 in senescent human fibroblasts

The state of cellular senescence is characterised by an irreversible arrest in the G1 phase of the cell cycle. It has previously been shown that three cell cycle genes, cyclin A, cyclin B and cdc2, are not expressed in senescent human fibroblasts. All three gene products have functions after S-phase entry, so that their suppression cannot explain the irreversible G1 arrest. Here, we report that the abundance of transcripts from two other cell cycle genes, cdk2 and cdk4, thought to act during G1—>S progression, is significantly diminished in senescent cells of the diploid human fibroblast line WI-38. Surprisingly, two other cyclins, D1 and E, behave in a completely different way, in that their expression is elevated in senescent cells, especially under conditions of serum starvation. Both the synthesis and the steady-state level of cyclin D1 protein were also found to be markedly higher in senescent cells (3- to 6-fold). Cyclins D1 and E are thus the first genes shown to be overexpressed or deregulated in senescent cells. It is tempting to speculate that this deregulation may be due to the absence, in senescent cells, of a regulatory loop that would normally control their expression. This is supported by our finding that cyclin E-associated kinase activity in senescent cells is reduced approx. 14-fold. Our data also suggest that the deregulated expression of cyclin D1 and E is not sufficient to drive senescent cells into DNA replication.

Human cyclin D1 encodes a labile nuclear protein whose synthesis is directly induced by growth factors and suppressed by cyclic AMP

We show that the cyclin D1 gene is regulated by a variety of growth factors in human diploid fibroblasts (WI-38). Expression of cyclin D1 mRNA is low in quiescent WI-38 cells and reaches a maximum around 10 hours after serum stimulation, i.e. approximately 8 hours prior to the onset of DNA synthesis. A cyclin D1-specific antiserum raised against a bacterially expressed fusion protein detected a 39 kDa polypeptide in WI-38 cells. In agreement with the RNA expression data, cyclin D1 protein synthesis is also serum-inducible, reaching a maximum around 9 hours post-stimulation. The results obtained by pulse-chase experiments, cell fractionation and immunostaining techniques strongly suggest that cyclin D1 is a labile protein (t1/2 approximately 38 min), which is located in the nucleus. Cyclin D1 is directly induced by growth factors, i.e. in the presence of cycloheximide, and its expression does not significantly fluctuate during the cell cycle in synchronized cells. Cyclin D1 therefore fundamentally differs from “classical” cyclins, such as the mitotic cyclin B, whose expression is clearly cell cycle-dependent. Cyclin D1 may rather establish a direct link between growth control mechanisms and the cell cycle. Interestingly, cyclin D1 expression is stimulated by the protein kinase C activator TPA, but suppressed by dibutyryl-cAMP and the adenylate cyclase inducer forskolin, pointing to multiple regulatory pathways controlling cyclin D1 expression.