[Media's Stranglehold on Storm and Stress - The Sorrows of Generation Z about Sex and Gender]

Media's Stranglehold on Storm and Stress - The Sorrows of Generation Z about Sex and Gender Abstract: The feeling of not belonging to one's birth sex is not new; one can trace this phenomenon back even to ancient mythology. Although it has always been rare, there has recently been a sharp increase in gender identity deviations among adolescents. This text addresses this problem by asking to what extent this development also results from upheavals in the cultural landscape and, above all, in media technology. Do they cause young people to believe they are in the "wrong gender" and, in extreme cases, to strive for transition? We present the most salient cornerstones of the planned German self-determination law (Self-ID), most of which, however, are unlikely to do justice to the underlying problem. The text concludes by describing several unanswered questions concerning this matter and by attempting to propose first answers. The advantages of a gender-exploratory over the trans affirmative therapy approach are summarized.

"Glass fairies" and "bone children": adolescents and young adults with anorexia nervosa show positive reactions towards extremely emaciated body pictures measured by the startle reflex paradigm

In this study, we investigated the emotional processing of extremely emaciated body cues in adolescents and young adults with (n  =  36) and without (n =  36) anorexia nervosa (AN), introducing a new picture type, which was taken from websites that promote extreme thinness and is targeted specifically at adolescents interested in extreme thinness. A startle reflex paradigm was used for implicit reactions, while a self-assessment instrument was used for subjective responses. We found a significant group difference with a startle inhibition (appetitive response) among the patients and a startle potentiation (aversive response) among the controls, whereas no such difference for subjective measures was found. The results are in contrast to previous studies, which proposed a general failure to activate the appetitive motivational system in AN, but in keeping with findings from other addictions, where the same response pattern has been found. Implications for prevention and therapy are discussed.

[About the heterogeneity in adolescents with gender identity disorder: differential importance of psychiatric comorbidity and considerations of individual psychodynamics]

Gender identity disorder (GID), gender dysphoria (GD) respectively, is considered a multifactorial disease whose etiology is subject to complex bio-psycho-social conditions, each with different weighting. As a result, therapists, who treat children and adolescents with GID/GD, have to deal with a very heterogeneous group with individually varying causes, differing psychopathology and varying disease progression. In addition to general psychiatric aspects of development, particularly psychiatric comorbidity, but also the different individual psychodynamics--i. e. the specific constellation of conflicts and possible ego deficits and structural deficits in the learning history of the person are of differential importance. In regard to the indication for gender reassignment measures this sometimes is relevant for the decision. The difficulties arising for decision making and the usefulness of a systematic evaluation of case reports as a basis for further optimization of the treatment recommendations are illustrated by two case reports. In the course of this, also the disadvantages and potential dangers of too early diagnostic definition and introduction of gender somato-medical and legal measures are shown exemplarily.

A map of local adaptation in Arabidopsis thaliana

Local adaptation is critical for species persistence in the face of rapid environmental change, but its genetic basis is not well understood. Growing the model plant Arabidopsis thaliana in field experiments in four sites across the species' native range, we identified candidate loci for local adaptation from a genome-wide association study of lifetime fitness in geographically diverse accessions. Fitness-associated loci exhibited both geographic and climatic signatures of local adaptation. Relative to genomic controls, high-fitness alleles were generally distributed closer to the site where they increased fitness, occupying specific and distinct climate spaces. Independent loci with different molecular functions contributed most strongly to fitness variation in each site. Independent local adaptation by distinct genetic mechanisms may facilitate a flexible evolutionary response to changing environment across a species range.

[Subjective evaluation of DBT treatment by adolescent patients with eating disorders and the correlation with evaluations by their parents and psychotherapists]

OBJECTIVE

The subjective evaluation of a psychotherapeutic treatment may be an essential aspect of the recovery from an eating disorder. Our study investigates the subjective treatment evaluation by patients with eating disorders and the accordance with their parents' and psychotherapist's evaluation.

METHOD

In a sample of 41 eating-disorder patients (M(Age) = 16.3; SD = 1.26), their parents and psychotherapists, we used a questionnaire (FBB) to assess satisfaction with Dialectical Behavioral Therapy treatment.

RESULTS

Our results show good ratings, as well as good correlations between patients and parents.

CONCLUSIONS

The findings implicate the importance of assessing a subjective therapy rating in addition to objective parameters.

Short-term outcome of anorexia nervosa in adolescents after inpatient treatment: a prospective study

The current study describes the short-term outcome of adolescent inpatient population suffering from anorexia nervosa (AN) and analyzes the clinical predictors of poor outcome in these patients. Fifty-seven female AN patients (mean = 15.8, SD = 1.3) admitted for inpatient treatment to a specialized eating disorder unit at a university medical center were reassessed 1 year after being discharged. Assessments were made at the beginning and at the end of the inpatient treatment as well as at the 1-year follow-up. Self-rating data and expert-rating interview data were obtained. Adequate data for 55 (96.5%) cases allowed for the assignment of an outcome category. A total of 28.1% of the patients' cases showed a good outcome, meaning the patients fully recovered, and 8.8% had an intermediate outcome, and 59.6% of the patients' cases had a poor outcome. Significant predictors of poor outcome included the patient's BMI at the beginning of the treatment as well as psychiatric comorbidity, and purging behavior. Adolescent AN is a severe disorder with a poor outcome in a substantial amount of adolescents.

Gender identity disorders in childhood and adolescence: currently debated concepts and treatment strategies

INTRODUCTION

Gender identity disorders (GID) can appear even in early infancy with a variable degree of severity. Their prevalence in childhood and adolescence is below 1%. GID are often associated with emotional and behavioral problems as well as a high rate of psychiatric comorbidity. Their clinical course is highly variable. There is controversy at present over theoretical explanations of the causes of GID and over treatment approaches, particularly with respect to early hormonal intervention strategies.

METHODS

This review is based on a selective Medline literature search, existing national and international guidelines, and the results of a discussion among experts from multiple relevant disciplines.

RESULTS

As there have been no large studies to date on the course of GID, and, in particular, no studies focusing on causal factors for GID, the evidence level for the various etiological models that have been proposed is generally low. Most models of these disorders assume that they result from a complex biopsychosocial interaction. Only 2.5% to 20% of all cases of GID in childhood and adolescence are the initial manifestation of irreversible transsexualism. The current state of research on this subject does not allow any valid diagnostic parameters to be identified with which one could reliably predict whether the manifestations of GID will persist, i.e., whether transsexualism will develop with certainty or, at least, a high degree of probability.

CONCLUSIONS

The types of modulating influences that are known from the fields of developmental psychology and family dynamics have therapeutic implications for GID. As children with GID only rarely go on to have permanent transsexualism, irreversible physical interventions are clearly not indicated until after the individual's psychosexual development ist complete. The identity-creating experiences of this phase of development should not be restricted by the use of LHRH analogues that prevent puberty.

Psychopathology in elite rhythmic gymnasts and anorexia nervosa patients

This study investigates current psychopathology and psychological distress in elite rhythmic gymnasts. Due to a strong emphasis on leanness in aesthetic sports and the controversial findings in literature regarding the role of anorexia nervosa (AN) in such sports, we compared elite rhythmic gymnasts (n=51) to inpatients with AN (n=55) as a disease control group and to high school students (n=53) as a "normal" control group. We assessed psychopathology using the Symptom Checklist (SCL-90-R). Moreover, body height, weight, Body Mass Index (BMI) and the presence of amenorrhea were assessed. Regarding physical aspects, the rhythmic gymnasts showed an intermediate position between the two other groups. In terms of psychopathology, significant differences were found between the gymnasts and the AN patients, while no differences were detected between the gymnasts and the "normal" control group. Depression discriminated best between the three groups. Elite rhythmic gymnasts may show a lean, almost anorexic-like physique. Nevertheless, no psychological distress comparable to that of AN patients was found. Therefore, even though analogies to AN might seem obvious in elite rhythmic gymnasts, this study is putting emphasis on the importance of a careful consideration of psychological distress and psychopathology.

[Dialectical behavior therapy for adolescents with anorexia and bulimia nervosa (DBT-AN/ BN)--a pilot study]

Dialectical behavior therapy (DBT) was originally developed by Linehan (1993a, b) and modified by Miller et al. (1997) for suicidal adolescents with borderline personality features. Meanwhile, this therapy has also successfully applied in other adult clinical groups. The prior aim of the study is to evaluate the effectiveness of DBT for inpatient adolescents with anorexia and bulimia nervosa. In this pilot study (n=31) the efficacy of this treatment will be evaluated in a pre-post comparison. Different instruments will be used (SIAB, EDI-2, SCL-90-R, FBB). The first results are promising and we must hope that this new approach will improve the future treatment.

Body image and attitudinal aspects of eating disorders in rhythmic gymnasts

BACKGROUND

Aesthetic sports, especially on a competitive level, are often considered as a risk factor for the development of an eating disorder. A few studies have examined this issue in rhythmic gymnasts, but no reports on body image disturbance exist for these athletes compared to anorectic patients.

SAMPLING AND METHODS

Fifty elite rhythmic gymnasts (average age 14.8 years) including the German national team, 58 female patients with anorexia nervosa (AN; average age 15.5 years), and 56 high school girls (average age 14.9 years) completed the Eating Disorder Inventory-2 and the Test for Detecting Body Image Distortion in Children and Adolescents (Test zur Erfassung der Körperbildstörung bei Kindern und Jugendlichen). Furthermore, body weight and height, body mass index, presence of amenorrhea and frequency of exercise were surveyed.

RESULTS

Body mass index was significantly lower in the elite rhythmic gymnasts than in the high school students, and significantly higher than in the AN patients. Both the elite rhythmic gymnasts and the AN patients were significantly smaller than the high school students. The elite rhythmic gymnasts trained significantly more frequently compared with the AN group and the high school group. Regarding the Eating Disorder Inventory-2 and the Test for Detecting Body Image Distortion in Children and Adolescents, AN patients scored significantly higher on all explored subscales than both the elite rhythmic gymnasts and the high school students.

CONCLUSIONS

Even though some physical similarities were found for the elite rhythmic gymnasts and the AN patients, contrary to previous studies, no noticeable problems related to attitudinal aspects of eating disorders were detected in the elite rhythmic gymnasts. A mildly distorted body image of the abdomen was identified in elite rhythmic gymnasts, while AN patients expressed a broad body image distortion and students expressed no body image distortion. Our data do not allow us to draw conclusions regarding prevalence rates, long-term effects or male athletes.

GER1, a GDSL motif-encoding gene from rice is a novel early light- and jasmonate-induced gene

The reaction of the rice mutant HEBIBA differs from that of wild-type rice in that the mutant responds inversely to red light and is defective in the light-triggered biosynthesis of jasmonic acid (JA). Using the wild type and the HEBIBA mutant of rice in a differential display screen, we attempted to identify genes that act in or near the convergence point of light and JA signalling. We isolated specifically regulated DNA fragments from approximately 10 000 displayed bands, and identified a new early light- and JA-induced gene. This gene encodes an enzyme containing a GDSL motif, showing 38 % identity at the amino acid level to lipase Arab-1 in Arabidopsis thaliana. The GDSL CONTAINING ENZYME RICE 1 gene (GER1) is rapidly induced by both red (R) and far-red (FR) light and by JA. The results are discussed with respect to a possible role for GER1 as a negative regulator of coleoptile elongation in the context of recent findings on the impact of JA on light signalling.

Familienorientierte Gruppentherapie zur Behandlung von Patientinnen mit Anorexia und Bulimia nervosa - eine Pilotstudie

Zusammenfassung: Fragestellung: Familientherapie hat sich in der Behandlung von Anorexia (AN) und Bulimia nervosa (BN) als effektiv erwiesen. Die kognitiv-behaviorale Behandlung hat bei BN im Erwachsenenbereich gute Effekte erzielt, allerdings gibt es kaum Studien, die die Wirksamkeit psychotherapeutischer Behandlungen in der Adoleszenz untersucht haben. Da bei der Mehrzahl der Betroffenen die AN häufig während der mittleren Adoleszenz auftritt und die BN während der späteren Adoleszenz beginnt, ist die Entwicklung von Behandlungsprogrammen für Essstörungen im Jugendalter dringend angezeigt. In diesem Beitrag wird ein Behandlungsprogramm dargestellt, das im Rahmen eines gruppentherapeutischen Vorgehens störungsspezifische (größtenteils psychoedukative) mit zieloffenen Therapiekomponenten verbindet. Die Patientinnen nehmen gemeinsam mit ihren Eltern an dem Gruppenangebot teil. Methodik: Es erfolgt eine Evaluation des Behandlungskonzepts anhand eines «single-group designs», und Veränderungen werden gemessen. Ergebnisse: Insgesamt nahmen 32 stationäre Patientinnen (29 mit AN; 3 mit BN) mit ihren Eltern bzw. allein erziehenden Müttern an dem Behandlungsprogramm teil. Die Tatsache, dass keine Familie die Behandlung abgebrochen hat, weist auf eine hohe Akzeptanz hin. Prä-post-Analysen zeigen während der sechs Wochen einen Rückgang der Essstörungssymptomatik. Schlussfolgerungen: Vor- und Nachteile dieses Behandlungsprogramms werden diskutiert und die Einschränkungen der Pilotstudie kritisch beleuchtet.

Chemokine IL-8 and chemokine receptor CXCR3 and CXCR4 gene expression in childhood acute lymphoblastic leukemia at first relapse

In this study, we examined the gene expression of interleukin (IL)-8, CXCR3, and CXCR4 in leukemic cells from 100 children with relapsed B-cell progenitors (BCP) acute lymphoblastic leukemia (ALL), using quantitative real-time polymerase chain reaction (RT-PCR). IL-8, CXCR3, and CXCR4 were expressed in almost all bone marrow (BM) samples. The CXCR4 expression significantly correlated with known prognostic factors at relapse: time point and site of relapse. Patients who had a combined BM relapse (n=21) had lower IL-8 and CXCR4 expression than those who had an isolated BM relapse (n=79). The CXCR3 expression was higher in female patients (n=39) than in male patients (n=61). However, this did not reach prognostic relevance in relapsed ALL.

[Treatment of eating disorders in adolescents--the view of a child and adolescence psychiatric hospital]

The paper presents--in the sense of clinical guidelines--reality of clinical care in a child and adolescence university hospital specialised on eating disorders. Need of a multimodal therapeutic approach is emphasized, including normalisation of weight and eating behaviour, nursing and pedagogical measures, individual, group and family therapy, completed by body therapy, art and music therapy and in case psychopharmacotherapy. Recommendations for overcoming weak spots are made.

Interaction of bone marrow stromal cells with lymphoblasts and effects of predinsolone on cytokine expression

Cytokines play a key role in the differentiation, growth and survival of hematopoietic cells in the bone marrow (BM) stroma microenvironment. The mechanisms by which stromal derangements may contribute to the evolution of hematopoietic neoplasias are largely unknown. Here, we characterized BM stromal cells isolated from children with acute lymphoblastic leukemia and determined the effect of the interaction between stromal cells and lymphoblasts on cytokine expression as well as the effect of prednisolone using mono- and co-culture models. The analyses demonstrate that (1) stromal cells and lymphoblasts display different patterns of cytokine gene expression individually. (2) Stromal cells influence gene expression of cytokines in lymphoblasts and vice versa. (3) Glucocorticoid substitution inhibit cytokine gene expression in stromal cells. These findings indicate that stromal cells are important components involved in malignant hematopoiesis and also in response to therapy.

Spin-labelled Au nanoparticles

A series of Au nanoparticles functionalised with nitroxide spin labels has been prepared and studied by EPR spectroscopy. Samples with low coverage of the spin label were used to investigate the dynamics of the surface-attached labels at different distances from the Au surface. The rotational correlation times of spin labels vary from 10(-10) s to more than 3 x 10(-9) s, depending on the chain length of the label and the surrounding ligand. The samples with higher coverage of the spin label show an increasing contribution of the exchange interaction between nitroxides adsorbed in a close proximity to each other on the same nanoparticle. Quantitative analysis of the EPR spectra of these samples suggests the presence of non-equivalent binding sites on the surface of Au nanoparticles. Additionally, EPR signals of isolated radical pairs were observed at intermediate coverage.

Cross-Couplings of Alkyl Electrophiles under “Ligandless” Conditions: Negishi Reactions of Organozirconium Reagents

This report establishes that simple, "ligandless" palladium complexes can catalyze the first zirconium-Negishi reactions of alkyl electrophiles. In view of the attractiveness of ligandless catalysts (cost, simplicity, and ease of purification), these observations add a significant and intriguing new dimension to the development of effective palladium-based processes for coupling alkyl electrophiles.

Levels of the soluble, 55-kilodalton isoform of tumor necrosis factor receptor in bone marrow are correlated with the clinical outcome of children with acute lymphoblastic leukemia in first recurrence

BACKGROUND

It has been shown that the soluble, 55-kilodalton isoform of tumor necrosis factor receptor (sTNFRp55) enhances tumor survival by exhibiting competitive ligand binding. The objective of the current study was to determine the levels of sTNFRp55 and their impact on outcome in 106 children with acute lymphoblastic leukemia (ALL) in first recurrence.

METHODS

Between January 1997 and December 2001, bone marrow (BM) samples were collected from 106 children with a first recurrence of ALL at diagnosis. These patients were enrolled in the Berlin-Frankfurt-Münster (BFM) ALL recurrence trial, ALL-REZ BFM 90-96. Levels of sTNFRp55 in BM samples were determined with a commercially available enzyme-linked immunosorbent assay kit. Event-free survival (EFS) and overall survival were assessed from the date of study entry or the date of randomization, as appropriate.

RESULTS

The mean sTNFRp55 level (+/- standard deviation) was 3.40 +/- 2.57 ng/mL. High levels of sTNFRp55 were associated with shorter duration of first complete remission and observation time as well as poor response to chemotherapy. Most importantly, the probability of EFS (pEFS) at 3 years was significantly worse for children with recurrent ALL who had sTNFRp55 levels greater than the median value (> 2.77 ng/mL) compared with patients who had levels that were less than the median value (pEFS: 0.44 +/- 0.10 ng/mL vs. 0.12 +/- 0.10 ng/mL; P = 0.006). It is noteworthy that the sTNFRp55 levels in 22 children with recurrent, TEL-AML1-positive ALL ([t(12;21)(p13;q22)]; 2.69 +/- 1.05 ng/mL) were significantly lower compared with the levels in children who had TEL-AML1-negative ALL (3.34 +/- 1.49 ng/mL; P < 0.05).

CONCLUSIONS

The results indicated that a high sTNFRp55 level represents a negative prognostic factor for children with recurrent ALL in terms of EFS and overall survival.

Protection of mice against Philadelphia chromosome-positive acute lymphoblastic leukemia by cell-based vaccination using nonviral, minimalistic expression vectors and immunomodulatory oligonucleotides

PURPOSE

Childhood Philadelphia chromosome positive (Ph(+)) acute lymphoblastic leukemia (ALL) has a poor prognosis. Because leukemia cell burden is reduced but not eradicated by polychemotherapy, improved treatment strategies should enhance those immune mechanisms responsible for the maintenance of complete remission. The aim of this study was to evaluate the protection of mice challenged with the syngeneic Ph(+) ALL cell line BM185 using genetically modified leukemia cell vaccines and immunomodulating oligonucleotides.

EXPERIMENTAL DESIGN

Because retroviral vectors are ineffective at transducing nondividing primary cells from human hematopoietic malignancies, we first evaluated nonviral techniques (electroporation and ballistic transfer) using minimalistic immunogenically defined gene expression vectors to generate B7.1 or granulocyte macrophage colony-stimulating factor (GM-CSF)-expressing BM185 cells. Subsequently, protective vaccination experiments with these cells were performed in a leukemia challenge mouse model.

RESULTS

Electroporation yielded a high transfection rate (82.6% for B7.1) with moderate GM-CSF secretion/1 x 10(6) cells (228 pg), whereas ballistic transfer led to a lower transfection rate (30.9%) with high GM-CSF secretion (614 pg). Secondly, we immunized mice with B7.1/interleukin 2- or B7.1/GM-CSF-expressing BM185 cell vaccines. We observed a better protection of mice that received the B7.1/GM-CSF vaccine compared with these receiving the B7.1/interleukin 2 vaccine. Protection was additionally enhanced by application of a double stem-loop immunomodulating oligonucleotide containing CpG motifs.

CONCLUSION

Our data indicate that immunization with B7.1/GM-CSF-expressing cell vaccines generated by electroporation and application of double stem-loop immunomodulating oligonucleotide protected mice against a murine Ph(+) ALL challenge. Ultimately, this approach may also lead to clinical benefit in patients with Ph(+) ALL.

Characterization of cytokine, growth factor receptor, costimulatory and adhesion molecule expression patterns of bone marrow blasts in relapsed childhood B cell precursor all

Relapse of childhood acute lymphoblastic leukaemia (ALL) comprises a leading challenge of investigation. Characterization of leukaemic cells regarding their potency to express growth factors and surface molecules can provide insight into their aberrant biology. Thus, we analyzed bone marrow blasts from 10 children with relapsed B cell precursor ALL. The gene and protein expression of essential haematopoietic growth factors (IL-2, IL-4, IL-7, IL-10, IL-15, IFN-gamma, G-CSFR), their corresponding receptors as well as the expression pattern of adhesion molecules (ICAM-1, CD58) and costimulatory proteins (CD40, CD40L, B7.1, B7.2, CD28, MHC-I and II) was analyzed by RT-PCR and flow cytometry. Constitutive gene expression was found for IL-7, IL-10, IL-15 and IFN-gamma and their corresponding receptors. Flow-cytometric analysis showed that IL-10R, IL-7Ralpha, IL-4Ralpha and the gamma(c)chain are constitutively expressed, and that some cells bear the G-CSFR. IL-10 and IL-15 protein-producing leukaemic cells were easily detectable. The neoplastic cells mainly lack B7.1, and ICAM-1 is mostly decreased. Furthermore, high CD40, and, surprisingly, CD40L expression could be found. These studies show that ALL cells are likely to be sensitive to many growth factors and some factors are produced by the neoplastic cell itself. The secretion of IL-10 by leukaemic cells, and the absence or downregulation of conventional adhesion and costimulatory molecules might represent an effective mechanism of escape of immune surveillance in relapsed ALL.

Expression analysis and characterization of alternatively spliced transcripts of human IL-7Ralpha chain encoding two truncated receptor proteins in relapsed childhood all

In the family of cytokines and cytokine receptors, alternative splicing of pre-mRNA is a frequently observed process that generates different protein isoforms from a single genetic locus. The splicing-derived cytokine receptor protein isoforms are mostly soluble receptors or show alterations in their cytoplasmic domain. It is possible that receptor abnormalities or a pathological ratio of different isoforms may contribute to leukaemia by circumventing normal growth factor control or altering the balance of proliferation and differentiation. IL-7 plays a critical role in early stages of both B and T cell maturation. Moreover, it stimulates the expansion of mature T cells including anti-tumour reactive cells as well as a number of T and B cell malignancies underlining its potential importance for deregulated lymphoid proliferation and leukaemogenesis. Here, we present detailed data on the expression of the interleukin 7 receptor alpha chain (IL-7Ralpha) in leukaemic cells from 210 children with acute lymphoblastic leukaemia (ALL) and describe two novel alternatively spliced transcripts of human IL-7Ralpha coding for truncated receptor proteins which are still capable of binding IL-7. IL-7Ralpha mRNA expression was more frequent in more mature pre-B ALL [91% (30/33)] than in common [81% (81/100)] or pro-B ALL [64% (18/28)], or even in T ALL [64% (29/45)]. These results are in concordance with flow cytometric analyses on the proportion of IL-7Ralpha bearing cells among total blast cell population. Our results lead us to assume that splicing derived IL-7Ralpha isoforms play a potential role in modulating IL-7 signal transduction and might be important for the pathogenesis of leukaemia.

Extensive alternative splicing of interleukin-7 in malignant hematopoietic cells: implication of distinct isoforms in modulating IL-7 activity

Interleukin-7 (IL-7) plays a pivotal role in early stages of normal B and T cell development. In addition, IL-7 stimulates the proliferation of both antitumor reactive cells and a number of T and B cell malignancies, underlining its significance for leukemogenesis. However, its exact role in the process of pathologic maturation of lymphocytes and regulation of the immune response is not completely understood. As alternative splicing of pre-mRNA has been shown to be involved in the control of gene expression, and splicing-derived protein isoforms with antagonistic activity have been found, we assessed the mRNA-expression of IL-7 and its previously described alternative splice variant lacking exon 4, IL-7delta4, in leukemic cells from children with acute lymphoblastic leukemia (ALL). PCR of full-length IL-7 cDNA enabling the competitive amplification of both variants led to the amplification of diverse unexpected PCR products. The sequence data demonstrated the existence of three additional in-frame splice variants resulting from exon skipping of exon 3 or exon 5 or both in combination with exon 4. We named these IL-7delta3/4, IL-7delta4/5, and IL-7delta3/4/5. Furthermore, three out-of-frame splice variants were identified, IL-7(-56bpExon2), IL-7delta4(-56bpExon2), and IL-7delta3/4/5(-56bpExon2), in which, in addition to the aforementioned exon skipping, 56 bp of the 3' end of exon 2 are omitted. Our results led us to assume that splicing-derived IL-7 isoforms play a potential role in modulating IL-7-mediated biologic effects. Further studies are required to clarify the significance of the diverse IL-7 protein isoforms for the regulation of IL-7 function and the pathogenesis of leukemia.

Guanine nucleotides and pertussis toxin reduce the affinity of histamine H3 receptors on AtT-20 cells

Agonist occupancy of high affinity histamine H3 receptors on AtT-20 cells induces increased ACTH release. However, the signal transduction process by which this occurs is presently unknown. As a first step in characterizing this pathway, we have examined the effects of a variety of nucleotides and nucleotide analogs on Na-methylhistamine binding to these receptors. Nonhydrolyzable guanine nucleotide analogs inhibit up to 40% of the [3H]Na-methylhistamine binding by increasing the dissociation rate of the ligand from the receptor and, thereby, reducing receptor affinity. Pertussis toxin also decreases the affinity of the H3 receptors and ADP ribosylates a 41 kDa protein. Neither GTP gamma S nor pertussis toxin change Bmax. These data indicate that the H3 receptors on these cells are coupled to a G protein of the Gi subclass.

High affinity histamine H3 receptors regulate ACTH release by AtT-20 cells

The distribution of high affinity histamine H3 receptors in various tissues from guinea pig has been determined using [3H]N alpha-methylhistamine binding. In the course of those studies, it was observed that the pituitary gland contains H3 receptors. Using this radioligand, we have now identified and characterized H3 receptors on' the AtT-20 cell line from a murine anterior pituitary tumor. This line has approximately 5000 high affinity (KD = 0.7 nM) H3 binding sites per cell. Competition binding with standard H1, H2 and H3 agents has confirmed that these sites are, indeed, H3 receptors. The H3 receptor specific agonist, (R)-alpha-methylhistamine increased the release of adrenocorticotropic hormone (ACTH) from AtT-20 cells in a dose- and time-dependent manner, while histamine and the H2 agonist dimaprit were significantly less potent. Furthermore, this response was blocked by thioperamide, an H3 receptor specific antagonist, but not by the H1 and H3 antagonists, chlorpeniramine and cimetidine. These results identify, for the first time, a cell line expressing H3 receptors and indicate that the high affinity histamine H3 receptor regulates ACTH release from that cell.

Characterization and tissue distribution of H3 histamine receptors in guinea pigs by N alpha-methylhistamine

We have used [3H]N alpha-methylhistamine to characterize H3-binding in the guinea pig brain and to study its tissue distribution. Kinetic and equilibrium binding experiments indicate a single class of high affinity sites in membranes isolated from guinea pig brain tissue (Kd = 0.4 nM, Bmax = 41 fmol/mg of protein). Competition binding experiments have confirmed that this ligand associates with H3-receptors and, under the conditions used in these experiments, does not bind to H1- or H2-receptors. Although there was some binding in the ileum and large intestine, H3-binding was found primarily in the central nervous system.

Embryotoxicity and mutagenicity of mycotoxins

Embryotoxicity: Aflatoxin B1 (AFB1), G1 (AFG1), and Patulin (PA) were investigated in NMRI mice for embryotoxic and teratogenic activity. These three mycotoxins were injected intraperitoneally or given orally on day 12 and 13 of pregnancy. AFB1 (15, 45, and 90 mg/kg ip or 45 mg/kg po) produced moderate retardation in fetal development and a dose-related increase of cleft palates, wavy ribs, and diaphragm changes. The effects after injection of AFG1 (45 to 90 mg/kg ip) were reduction of fetal weights, increase of diaphragm changes, and malformations of kidneys. PA (1, 25, 2, 5, and 3.75 mg/kg ip or 3.75 mg/kg po) was found to elevate the rate of cleft palates after 3.75 mg/kg. Dominant lethal assay: Neither PA (2, 5, and 5 mg/kg ip) nor AFB1 (15 and 45 mg/kg ip) increased the frequency of the dominant lethal mutations. Both mycotoxins showed no mutagenic activity in this test system. Cytogenetic studies: The capability of the three mycotoxins AFB1, AFG1, and PA to induce chromosome damages in vivo has been tested in the Chinese hamster by examination of bone marrow cells. The substances were tested in each of two oral doses (AFB1: 12, 5, and 25 mg/kg; 25 and 50 mg/kg; PA: 10 and 20 mg/kg). The present data show that the three mycotoxins induce chromosome aberrations in the following order of activity: PA greater than AFB1 greater than AFG1.

Mutagenicity testing of doxylamine succinate, an antinauseant drug

Doxylamine succinate (DA), a compound which was formerly used as an antinauseant during pregnancy, showed no substantial mutagenicity in mouse embryos following transplacental exposure. A small dose-dependent induction of chromosomal aberrations was found in mouse embryos on day 11 of gestation. No induction of sister chromatid exchanges (SCE) was found in embryos on day 11 of gestation. A micronucleus test with fetal blood on day 17 of gestation was negative. Additionally, DA was negative in Chinese hamster bone marrow in vivo (micronuclei) and in human lymphocyte cultures in vitro (SCE).

Central muscarinic cholinergic influences on ethanol sensitivity in long-sleep and short-sleep mice

Sensitivity to the hypnotic effects of ethanol was increased selectively by central administration of muscarinic agonists. Carbachol or oxotremorine, but not nicotine, i.c.v., enhanced hypnotic sensitivity to ethanol markedly, as measured by blood ethanol concentration at loss or righting response, in short-sleep (SS) but not long-sleep (LS) mice. Likewise, the acetylcholinesterase inhibitor, neostigmine, i.c.v., differentially enhanced hypnotic sensitivity to ethanol in these mouse lines. LS and SS mice were equally sensitive to the hypothermic effects of carbachol, neostigmine or oxotremorine i.c.v. The muscarinic antagonists, atropine or pirenzepine, i.c.v., were without effect on ethanol sensitivity, but these compounds antagonized muscarinic agonist-enhanced ethanol sensitivity in SS mice effectively. Pirenzepine, and M1 selective antagonist, produced a parallel shift in the oxotremorine dose-response curve, indicating that the enhanced hypnotic sensitivity to ethanol may be due to interaction of oxotremorine with M1 muscarinic receptors. This possibility was supported by the finding that atropine and pirenzepine which are known to have comparable affinities for M1 but not M2 receptors, had comparable potencies in antagonizing the action of oxotremorine or neostigmine. The results suggest that LS and SS mice differ genetically in neuronal processes activated by specific muscarinic agonists and are consistent with the hypotheses that ethanol acts in part via membrane receptor coupling to intracellular processes known to mobilize intracellular Ca++.

Brain neurotensin receptors in mice bred for differences in sensitivity to ethanol

The hypothesis that some of ethanol's acute effects are mediated via neurotensinergic systems was investigated by characterizing neurotensin (NT) receptors in mice (LS and SS) selectively bred for differences in sensitivity to ethanol. [3H]Neurotensin binding in brain membranes from both mouse lines was specific, saturable, reversible, and linear with protein concentrations. Subcellular localization studies showed specific NT binding to be concentrated in the microsomal/synaptosomal fractions. Scatchard analyses of [3H]NT binding indicated similar KD values for membranes from various brain regions of LS and SS mice. However, Bmax values in frontal cortex, cerebellum, and striatum were greater in SS than in LS mice. In competitive binding studies IC50 values were lower for NT8-13 than for NT1-13, and IC50 values for NT1-8, NT1-11, D-Trp11-NT, and D-Tyr11-NT were greater than 1000 nM. Association and dissociation rate constants for [3H]NT and resulting KD values (0.8 nM) were similar for LS and SS brain membranes. Ethanol, in vitro, had no effect on NT binding characteristics, but as expected various cations markedly increased KD values.

Experience with mutagenicity testing of new drugs: viewpoint of a regulatory agency

Quality and quantity of mutagenicity testing were analyzed for drugs with new active compounds which were submitted for registration in the Federal Republic of Germany from mid 1982 to mid 1986. A large variety of deficiencies was found, applying to selection and number of mutagenicity tests as well as to test performances. Only 65 out of the 144 drugs submitted for registration were tested sufficiently in the initial phase of registration. From 1982 to 1986 this situation has not been changed markedly. Inadequate test performance still remains the main reason for insufficient testing, leading in some cases to artificially positive results. For in vivo tests the selection of test species was mainly motivated by technical reasons and not by characteristics of the test compound. Most of the insufficiencies were eliminated during the second phase of registration. In some cases insufficient mutagenicity testing led to consequences concerning risk-benefit assessment of the drug and its regulation.

Neurotensin selectively alters ethanol-induced anesthesia in LS/Ibg and SS/Ibg lines of mice

Neurotensin (NT) differentially altered ethanol-induced anesthesia as measured by duration of loss of righting response or by blood ethanol levels producing loss of righting response in mice (LS and SS) which were selectively bred for differences in response to ethanol. At doses of 5-500 ng i.c.v., NT increased ethanol sensitivity in SS mice, but not in LS mice, as measured by blood ethanol concentrations at loss of righting response. At higher doses, 0.5-10 micrograms i.c.v., NT enhanced the sensitivity of both SS and LS mice to ethanol-induced anesthesia. The hypothermic effect of ethanol determined at loss of righting response was not altered in either LS or SS mice at low doses of NT, but at higher doses NT enhanced ethanol-induced hypothermia in both lines of mice. The altered anesthetic sensitivity was specific for ethanol in that NT did not alter pentobarbital-induced sleep time in either LS or SS mice and halothane anesthesia was altered slightly only in LS mice. NT analogues, N-acetyl-NT8-13, and [D-Trp11]-NT but not NT1-8 enhanced the anesthetic action of ethanol in SS mice. Bombesin, cholecystokinin sulfate, substance P, [D-Trp8, D-Cys14]-somatostatin and corticotropin releasing hormone (CRF) were not effective in enhancing ethanol-induced anesthesia in LS or SS mice. CRF appeared to decrease ethanol sensitivity in LS but not in SS mice. Beta-Endorphin (beta-END) markedly increased the ethanol sensitivity of SS and to a lesser extent of LS mice at relatively high doses, e.g. 0.5-1.0 micrograms i.c.v. The results of the present study indicate that differences in brain sensitivity of LS and SS mice to ethanol may be mediated by genetic differences in NT systems. Likewise, NT, and probably beta-endorphin, may interact with other neurochemical processes that are involved in the mechanism of ethanol-induced anesthesia and that differ genetically in LS and SS mice.

Species differences in mutagenicity testing. II. Sister-chromatid exchange and micronucleus induction in rats, mice and Chinese hamsters treated with cyclophosphamide

Comparative investigations of sister-chromatid exchange (SCE) and micronucleus induction in the bone marrow of rats, mice and Chinese hamsters with the cytostatic alkylating mutagen cyclophosphamide (CP) revealed remarkable species differences in their mutagenic responses. With both test systems the sensitivities of the three species can be ranked into the order rat greater than mouse greater than Chinese hamster. More explicit results were obtained with the SCE test than with the micronucleus test within the same dose range. This may be due to the influence of species-related differences in the cytotoxic response to CP in the micronucleus test. These results show that clearly different mutagenic responses in different test species may be obtained in standard assays even with a compound which is metabolized in a very similar manner in all animal species.

Species differences in mutagenicity testing: I. Micronucleus and SCE tests in rats, mice, and Chinese hamsters with aflatoxin B1

Three animal species used in in vivo mutagenicity testing--rats, mice and Chinese hamsters--were compared with respect to their mutagenic response to the mycotoxin aflatoxin B1 (AFB1). The micronucleus test and the SCE test with bone marrow cells were chosen as test methods, employing similar protocols for all species. The mutagenic potential of AFB1 was detected with rats and mice but not with Chinese hamsters. Rats were more susceptible to the mutagenic action of AFB1 than mice with regard to the effective dose. A difference in sensitivity between males and females was evident in rats and mice: male animals exhibited higher induced micronucleus frequencies than females, and a clear SCE-inducing effect was only detectable in male animals. These results are in agreement with those of in vitro and carcinogenicity studies. They may be due to metabolic differences between the species and sexes, predominantly differences in glutathione conjugation of the reactive AFB1 epoxide and in the formation of the metabolite aflatoxicol. Furthermore, it could be demonstrated that AFB1 seems to be a more potent inducer of micronuclei than of SCE. Since our results obtained with rats and mice were clearly positive, but with the Chinese hamster the mutagenic potential of AFB1 was not detectable with the test systems used, it can be concluded that the choice of an "inappropriate" test species may lead to a false negative judgment on the genotoxic potential of a test compound.

Influence of chronic ethanol uptake and acute acetaldehyde treatment on the chromosomes of bone-marrow cells and peripheral lymphocytes of Chinese hamsters

Chinese hamsters received 10% (v/v) ethanol as their only liquid supply during 46 weeks. At the end of the drinking period the rate of chromosomal aberrations was determined in cultured lymphocytes. The cultures were set up with the blood from the retro-orbital plexus. Bone-marrow metaphases of the same animals were analysed with regard to sister-chromatid exchanges (SCE) after implantation of BrdU tablets in vivo. No cytogenetic effects were found in either test system. Another group of Chinese hamsters received acetaldehyde at 0.01, 0.1 amd 0.5 mg/kg by i.p. injection, and bone-marrow metaphases were analysed with respect to SCE. The SCE frequencies were elevated by acetaldehyde at 0.5 mg/kg, but not by the lower doses.

Simultaneous exposure of Chinese hamsters to ethanol and cigarette smoke: cytogenetic aspects

Chinese hamsters (Cricetulus griseus) were treated with ethanol, with cigarette smoke and with both. During the experimental period of 12 weeks a control group of animals (c) received water ad libitum, another water drinking group received a cigarette smoke treatment during the last 4 weeks (S). Another group received 20% (v/v) ethanol during the whole experimental period as the only liquid supply (E), and one group with the same ethanol treatment was simultaneously treated with cigarette smoke during the last 4 weeks of the experiment (ES). The investigation of bone marrow cells after 12 weeks with regard to chromosomal aberrations and sister chromatid exchanges revealed no effects. A high mitotic activity was found in the smoke treated groups.

Chromosomal analysis in bone-marrow cells of Chinese hamsters after treatment with mycotoxins

Mycotoxins are ubiquitously occurring metabolites of moulds that grow on foodstuffs. They are able to cause toxic diseases in man and animals. Aflatoxin B1 (AFB1), aflatoxin G1 (AFG1) and platulin (PA) induce chromosomal damage in Chinese hamster bone-marrow cells. With respect to the number of induced aberrant mitoses the 3 mycotoxins can be ranked in the order PA greater than AFB1 greater than AFG1.

The influence of ethanol treatment of cytogenetic effects in bone marrow cells of Chinese hamsters by cyclophosphamide, aflatoxin B1 and patulin

Chromosomes were investigated from the bone marrow of Chinese hamsters which received 10% (v/v) ethanol as the only liquid supply for a period of 9 weeks. At the end of the ethanol drinking period 1 group of animals received 2 oral doses of 80 mg/kg cyclophosphamide (CP), a second group received 2 oral doses of 25 mg/kg aflatoxin B1 (AFB1), a third group 2 oral doses of 20 mg/kg patulin (PA). The 2 applications were separated by 24 h. The intake of ethanol had no effect on the bone marrow chromosomes, and had no potentiating effect on CP induced aberrations. 9 weeks consumption of 10% (v/v) ethanol revealed likewise no influence on the frequencies of chromosomal aberrations induced by the indirect mutagen AFB1. However, the rate of chromosomal aberrations induced by the direct mutagen PA was clearly suppressed in ethanol drinking animals.