Premorbid school performance in twins concordant and discordant for bipolar disorder

BACKGROUND

Although the genetic risk to develop bipolar disorder is present from conception, the first frank symptoms of the illness generally become evident in late adolescence or early adulthood. However, except for pediatric bipolar disorder (PBD), it is still unclear when the first signs of the illness in adults become apparent and whether these are related to the genetic risk to develop bipolar disorder. This study examined whether underperformance at school precedes the onset of the illness and is a genetically related risk marker for developing bipolar disorder.

METHODS

Information on school performance was obtained using objective archival data from 53 bipolar twin pairs (24 monozygotic (MZ), 29 dizygotic (DZ)) and 42 healthy matched control twin pairs (23 MZ, 19 DZ).

RESULTS

Affected twin pairs completed significantly fewer years of education than did control twin pairs with no difference between bipolar patients and their non-bipolar cotwins. The underperformance at school in the affected twin pairs occurred in early adolescence at a significantly younger age than the control twin pairs and preceded the onset of the first frank episode of bipolar disorder by thirteen years. Median age at onset of underperformance was not different in the patients and their non-bipolar cotwins. The association between liability of bipolar disease and age of first underperformance was significant and could be explained by genetic factors.

LIMITATIONS

The sample is not a population based twin sample.

CONCLUSION

Underperformance at school during early adolescence may be a genetic marker for the vulnerability to develop bipolar disorder.

A dynamic model of circadian rhythms in rodent tail skin temperature for comparison of drug effects

Menopause-associated thermoregulatory dysfunction can lead to symptoms such as hot flushes severely impairing quality of life of affected women. Treatment effects are often assessed by the ovariectomized rat model providing time series of tail skin temperature measurements in which circadian rhythms are a fundamental ingredient. In this work, a new statistical strategy is presented for analyzing such stochastic-dynamic data with the aim of detecting successful drugs in hot flush treatment. The circadian component is represented by a nonlinear dynamical system which is defined by the van der Pol equation and provides well-interpretable model parameters. Results regarding the statistical evaluation of these parameters are presented.

Recommendations on the statistical analysis of the Comet assay

In 2010, the Statisticians in the Pharmaceutical Industry (PSI) Toxicology Special Interest Group met to discuss the design and analysis of the Comet assay. The Comet assay is one potential component of the package of safety studies required by regulatory bodies. As these studies usually involve a three-way nested experimental design and as the distribution of the measured response is usually either lognormal or lognormal plus a point mass at zero, the analysis is not straightforward. This has led to many different types of analysis being proposed in the literature, with several different methods applied within the pharmaceutical industry itself. This article summarises the PSI Toxicology Group's discussions and recommendations around these issues.

Willingness to Donate Human Samples for Establishing a Dermatology Research Biobank: Results of a Survey

There is a rising need for biomaterial in dermatological research with regard to both quality and quantity. Research biobanks as organized collections of biological material with associated personal and clinical data are of increasing importance. Besides technological/methodological and legal aspects, the willingness to donate samples by patients and healthy volunteers is a key success factor. To analyze the theoretical willingness to donate blood and skin samples, we developed and distributed a questionnaire. Six hundred nineteen questionnaires were returned and analyzed. The willingness to donate samples of blood (82.5%) and skin (58.7%) is high among the population analyzed and seems to be largely independent of any expense allowance. People working in the healthcare system, dermatological patients, and higher qualified individuals seem to be in particular willing to donate material. An adequate patient insurance as well as an extensive education about risks and benefits is requested. In summary, there is a high willingness to donate biological samples for dermatological research. This theoretical awareness fits well with our own experiences in establishing such a biobank.

Shortened treatment duration of glucocorticoid-induced skin atrophy in rats

Glucocorticoids (GCs) belong to the most widely used anti-inflammatory drugs at all. However, their topical use is limited by their side effect potential, with skin atrophy being the most prominent one. Thus, determining the atrophogenic potential of novel compounds is of importance for drug development. Currently, the most frequently performed model in the base and pharmaceutical research is the hr/hr rat model of GC-induced skin atrophy that lasts for 19 days. In this study, we analysed statistically skin atrophy experiments retrospectively to ascertain (i) the earliest time-point, at which skin atrophy is significantly induced; and (ii) whether the differences between the GC treatment groups change until the end of the experiment. We show here that the treatment duration of rat skin atrophy models might be reduced to 5 days for economical and ethical reasons.

Comparative analysis of the uterine and mammary gland effects of progesterone and medroxyprogesterone acetate

OBJECTIVES

In combined hormone replacement therapy (HRT) progestins are used to inhibit estradiol-activated uterine epithelial cell proliferation. In comparison to estradiol-only therapy, combined HRT leads to enhanced proliferation of mammary epithelial cells. In a quantitative mouse model, we assessed the balance between uterine and undesired mammary gland effects for two progestins that are widely used in HRT, progesterone and medroxyprogesterone acetate.

STUDY DESIGN

Mice were ovariectomized and after 14 days they were treated subcutaneously with either vehicle, estradiol (100 ng) or estradiol plus increasing doses of progesterone or medroxyprogesterone acetate for three weeks.

MAIN OUTCOME MEASURES

Measures for progestogenic mammary gland activity were stimulation of side-branching and stimulation of epithelial cell proliferation. Progestogenic activity in the uterus was assessed by measuring inhibition of estradiol-activated uterine epithelial cell proliferation. ED(50) and ID(50) values for the distinct readouts were obtained and dissociation factors for uterine versus mammary gland activity were calculated.

RESULTS

MPA demonstrated uterine activity and mitogenic activity in the mammary gland at the same doses. In contrast, progesterone showed uterine activity at doses lower than those leading to significant stimulation of epithelial cell proliferation in the mammary gland.

CONCLUSIONS

Progestins do not behave the same. Use of the natural hormone progesterone, but not MPA, in combined hormone therapy might offer a safety window between uterine effects and undesired proliferative activity in the mammary gland.

Effects of synthetic gestagens on fish reproduction

Although it is well known that estrogenic steroidal hormones are able to affect the sexual development and reproduction of fish at low concentrations, no data on environmental effects of the class of progestogenic hormones are available yet. Synthetic gestagens (progestins) are a component in oral contraceptives. Upon their use, a fraction of the progestins will be excreted via urine into the aquatic environment. On the basis of their pharmacological action in mammals, it is supposed that fish reproduction is the most sensitive endpoint for the progestin treatment. In order to test this assumption, the effects of two progestins currently marketed in contraceptive formulations, levonorgestrel (LNG) and drospirenone (DRSP), were investigated in adult fathead minnows (Pimephales promelas) following an Organization for Economic Cooperation and Development 21-d fish reproduction screening assay draft protocol with additional end points. Levonorgestrel was tested at measured concentrations of 0.8, 3.3, and 29.6 ng/L, and DRSP at concentrations of 0.66, 6.5, and 70 microg/L. Both tested progestins caused an inhibition of reproduction. For LNG, this occurred at concentrations of >or=0.8 ng/L, no no-observed-effect concentration (NOEC) could be defined. Higher concentrations resulted in masculinization of females with de novo synthesis of nuptial tubercles. Drospirenone treatment, however, affected the reproductive success of fathead minnow at concentrations of 6.5 microg/L and higher with a clear dose-response relationship and a NOEC of 0.66 microg/L, which is above environmentally relevant concentrations.

GPR30 does not mediate estrogenic responses in reproductive organs in mice

The G protein-coupled receptor Gpr30 (Gper) was recently claimed to bind to estradiol and to activate cytoplasmic signal transduction pathways in response to estradiol. However, there are conflicting data regarding the role of Gpr30 as an estrogen receptor (ER): several laboratories were unable to demonstrate estradiol binding to GPR30 or estradiol-activated signal transduction in Gpr30-expressing cells. To clarify the potential role of Gpr30 as an ER, we generated Gpr30-deficient mice. Although Gpr30 was expressed in all reproductive organs, histopathological analysis did not reveal any abnormalities in these organs in Gpr30-deficient mice. Mutant male and female mice were as fertile as their wild-type littermates, indicating normal function of the hypothalamic-pituitary-gonadal axis. Moreover, we analyzed estrogenic responses in two major estradiol target organs, the uterus and the mammary gland. For that purpose, we examined different readout paradigms such as morphological measures, cellular proliferation, and target gene expression. Our data demonstrate that in vivo Gpr30 is dispensable for the mediation of estradiol effects in reproductive organs. These results are in clear contrast to the phenotype of mice lacking the classic ER alpha (Esr1) or aromatase (Cyp19a1). We conclude that the perception of Gpr30 (based on homology related to peptide receptors) as an ER might be premature and has to be reconsidered.

Comparative analysis of the uterine and mammary gland effects of drospirenone and medroxyprogesterone acetate

The role of progestins in combined hormone therapy is the inhibition of uterine epithelial cell proliferation. The Women's Health Initiative study provided evidence for an increased risk of breast cancer in women treated with conjugated equine estrogens plus the synthetic progestin medroxyprogesterone acetate (MPA), compared with conjugated equine estrogens-only treatment. These findings continue to be discussed, and it remains to be clarified whether the results obtained for MPA in the Women's Health Initiative study are directly applicable to other progestins used in hormone therapy. In this study we compared in a mouse model the effects of the synthetic progestins, MPA, and drospirenone in two major target organs: the uterus and mammary gland. As quantitative measures of progestin activity, we analyzed maintenance of pregnancy, ductal side branching in the mammary gland, and proliferation of mammary and uterine epithelial cells as well as target gene induction in both organs. The outcome of this study is that not all synthetic progestins exhibit the same effects. MPA demonstrated uterine activity and mitogenic activity in the mammary gland at the same doses. In contrast, drospirenone behaved similarly to the natural hormone, progesterone, and exhibited uterine activity at doses lower than those leading to considerable proliferative effects in the mammary gland. We hypothesize that the safety of combined hormone therapy in postmenopausal women may be associated with a dissociation between the uterine and mammary gland activities of the progestin component.

In vivo characterization of estrogen receptor modulators with reduced genomic versus nongenomic activity in vitro

Estrogen receptor (ER) ligands that are able to prevent postmenopausal bone loss, but have reduced activity in the uterus and the mammary gland might be of great value for hormone therapy. It is well established that the classical ER can activate genomic as well as nongenomic signal transduction pathways. In this study, we analyse the in vivo behaviour of ER ligands that stimulate nongenomic ER effects to the same extent as estradiol, but show clearly reduced activation of genomic ER effects in vitro. Using different readout parameters such as morphological changes, cellular proliferation, and target gene induction, we are able to demonstrate that ER ligands with reduced genomic activity in vitro show a better dissociation of bone versus uterine and mammary gland effects than estradiol that stimulates genomic and nongenomic effects to the same extent. We conclude that pathway-selective ER ligands may represent an interesting option for hormone therapy.

Effect of introduced species and habitat alteration on the occurrence and distribution of euryhaline fishes in fresh- and brackish-water habitats on Aruba, Bonaire and Curaçao (South Caribbean)

We conducted an ichthyological survey during the dry season of 2006 on the semi-arid islands of Aruba, Bonaire and Curaçao to provide information on species composition, richness and distribution in natural and non-natural aquatic habitats. The dry season species assemblages (N = 9 species) comprised less species than the wet seasons, and these data refine our knowledge of the indigenous fish fauna and its refuge localities during phases of drought and ensuing high salinity. A hierarchical cluster analysis reveals that the three islands have different species compositions with Curaçao being the most diverse, probably due to its having the most habitats and freshwaters present throughout the year. Species richness was unrelated to salinity and species diversity was highest in canalised streams. In the dry season fewer amphidromous species are present than in the wet season. We found no significant effect of human-induced changes on the presence or absence of fish species in the Netherlands Antilles. The presence of exotic species (including Xiphophorus helleri on Aruba, a first record for this island, and Oreochromis mossambicus and Poecilia reticulata occurring on all three islands) did not have a clear effect on the presence of indigenous species, nor did human alteration of the habitats have an influence on the occurrence of fish species.

Assessing non-inferiority of a new treatment in a three-arm trial in the presence of heteroscedasticity

In this paper, we describe an adjusted method to facilitate non-inferiority tests in a three-arm design. While the methodology is readily available in the situation of homogeneous group variances, the adjusted method will also maintain the alpha-level in the presence of heteroscedasticity. We propose explicit criteria for an optimal allocation. Depending on the pattern of heterogeneity, remarkably unbalanced designs are power optimal. We will apply the method to a randomized clinical trial and a toxicological experiment.

The relevance of placental location at 20-23 gestational weeks for prediction of placenta previa at delivery: evaluation of 8650 cases

OBJECTIVE

To determine the correlation between placental position at 20-23 weeks and incidence of birth complications caused by placental position.

SUBJECTS AND METHODS

In an ongoing prospective study, placental position was determined by transabdominal sonography as part of anomaly scanning at 20-23 gestational weeks, followed by transvaginal sonography in uncertain or suspicious situations. Examination was performed in 9532 cases; feedback was obtained from 8650 patients (90.7%).

RESULTS

Transabdominal sonography was followed by transvaginal scan in 363 of 8650 cases (4.2%). In 8551 cases (98.9%), we found normal placental position, with the placenta not reaching the internal os and a Cesarean section rate of 17.1% (1458/8551). The incidence of 'low placental position', with the placenta reaching the internal os was 0.66% (57/8650), with a Cesarean section rate of 21% (12/57). In 0.49% (42/8650) of cases, the placenta overlapped the internal os at 20-23 weeks; Cesarean section because of placenta previa or bleeding was performed in 28 of 8650 cases (0.32%). Vaginal delivery was possible in 43% of cases (13/30), when the overlap did not exceed 25 mm. If the overlap exceeded 25 mm (12 cases), no vaginal delivery was reported. There was no reported case of placenta previa missed at the 20-23-week scan.

CONCLUSION

At 20-23 weeks, a combination of routine transabdominal and indication-based transvaginal location of placental position is a powerful tool in predicting placenta previa at delivery. The advantage of determining placental position at this stage of pregnancy is a low false-positive rate compared to at earlier stages of pregnancy. We conclude that an overlapping placenta at 20-23 weeks has the consequence of a high probability of placenta previa at delivery. An overlap of 25 mm or more at 20-23 weeks seems to be incompatible with later vaginal delivery.

Variability of human hepatic UDP-glucuronosyltransferase activity

The availability of a unique series of liver samples from human subjects, both control patients (9) and those with liver disease (6; biliary atresia (2), retransplant, chronic tyrosinemia type I, tyrosinemia, Wilson's disease) allowed us to characterize human hepatic UDP-glucuronosyltransferases using photoaffinity labeling, immunoblotting and enzymatic assays. There was wide inter-individual variation in photoincorporation of the photoaffinity analogs, [32P]5-azido-UDP-glucuronic acid and [32P]5-azido-UDP-glucose and enzymatic glucuronidation of substrates specific to the two subfamilies of UDP-glucuronosyltransferases. However, the largest differences were between subjects with liver disease. Glucuronidation activities toward one substrate from each of the UDP-glucuronosyltransferases subfamilies, 1A and 2B, for control and liver disease, respectively, were 1.7-4.5 vs 0.4-4.7 nmol/mg x min for hyodeoxycholic acid (2B substrate) and 9.2-27.9 vs 8.1-75 nmol/mg x min for pchloro-m-xylenol (1A substrate). Microsomes from a patient with chronic tyrosinemia (HL32) photoincorporated [32P]5-azido-UDP-glucuronic acid at a level 1.5 times higher than the other samples, was intensely photolabeled by [32P]5-azido-UDP-glucose and had significantly higher enzymatic activity toward p-chloro-m-xylenol. Immunoblot analysis using anti-UDP-glucuronosyltransferase antibodies demonstrated wide inter-individual variations in UDP-glucuronosyltransferase protein with increased UDP-glucuronosyltransferase protein in HL32 microsomes, corresponding to one of the bands photolabeled by both probes. Detailed investigation of substrate specificity, using substrates representative of both the 1A (bilirubin, 4-nitrophenol) and 2B (androsterone, testosterone) families was carried out with HL32, HL38 (age and sex matched control) and HL18 (older control). Strikingly increased (5-8-fold) glucuronidation activity was seen in comparison to HL18 only with the phenolic substrates. The results indicate that one or more phenol-specific UDP-glucuronosyltransferase 1A isoforms are expressed at above normal levels in this tyrosinemic subject.

Variability of human hepatic UDP-glucuronosyltransferase activity

The availability of a unique series of liver samples from human subjects, both control patients (9) and those with liver disease (6; biliary atresia (2), retransplant, chronic tyrosinemia type I, tyrosinemia, Wilson's disease) allowed us to characterize human hepatic UDP-glucuronosyltransferases using photoaffinity labeling, immunoblotting and enzymatic assays. There was wide inter-individual variation in photoincorporation of the photoaffinity analogs, [32P]5-azido-UDP-glucuronic acid and [32P]5-azido-UDP-glucose and enzymatic glucuronidation of substrates specific to the two subfamilies of UDP-glucuronosyltransferases. However, the largest differences were between subjects with liver disease. Glucuronidation activities toward one substrate from each of the UDP-glucuronosyltransferases subfamilies, 1A and 2B, for control and liver disease, respectively, were 1.7-4.5 vs 0.4-4.7 nmol/mg x min for hyodeoxycholic acid (2B substrate) and 9.2-27.9 vs 8.1-75 nmol/mg x min for pchloro-m-xylenol (1A substrate). Microsomes from a patient with chronic tyrosinemia (HL32) photoincorporated [32P]5-azido-UDP-glucuronic acid at a level 1.5 times higher than the other samples, was intensely photolabeled by [32P]5-azido-UDP-glucose and had significantly higher enzymatic activity toward p-chloro-m-xylenol. Immunoblot analysis using anti-UDP-glucuronosyltransferase antibodies demonstrated wide inter-individual variations in UDP-glucuronosyltransferase protein with increased UDP-glucuronosyltransferase protein in HL32 microsomes, corresponding to one of the bands photolabeled by both probes. Detailed investigation of substrate specificity, using substrates representative of both the 1A (bilirubin, 4-nitrophenol) and 2B (androsterone, testosterone) families was carried out with HL32, HL38 (age and sex matched control) and HL18 (older control). Strikingly increased (5-8-fold) glucuronidation activity was seen in comparison to HL18 only with the phenolic substrates. The results indicate that one or more phenol-specific UDP-glucuronosyltransferase 1A isoforms are expressed at above normal levels in this tyrosinemic subject.

Kappa-like indices of observer agreement viewed from a latent class perspective

It is common practice to assess consistency of diagnostic ratings in terms of 'agreement beyond chance'. To explore the interpretation of such a term we consider relevant statistical techniques such as Cohen's kappa and log-linear models for agreement on nominal ratings. We relate these approaches to a special latent class concept that decomposes observed ratings into a class of systematically consistent and a class of fortuitous ratings. This decomposition provides a common framework in which the specific premises of Cohen's kappa and of log-linear models can be identified and put into perspective. As a result it is shown that Cohen's kappa may be an inadequate and biased index of chance-corrected agreement in studies of intra-observer as well as inter-observer consistency. We suggest a more critical use and interpretation of measures gauging observer reliability by the amount of agreement beyond chance.

History of syringe sharing in prison and risk of hepatitis B virus, hepatitis C virus, and human immunodeficiency virus infection among injecting drug users in Berlin

BACKGROUND

Injecting drug users (IDU) are at risk of parenterally transmitted diseases such as hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infection. We investigated whether a history of syringe sharing in prison is a risk factor for these infections. In the longitudinal part of the study, HBV, HCV, and HIV seroincidence rates were determined.

METHODS

The participants were recruited by multisite-sampling at different agencies for IDU. Data on risk behaviour were obtained by a standardized questionnaire. Serological markers for HBV, HCV, and HIV were determined. Logistic regression analysis was performed to adjust for confounding effects.

RESULTS

A history of syringe sharing in prison was significantly associated with HBV (adjusted prevalence odds ratio [POR] = 3.9, 95% confidence interval [CI]: 2-10), HCV (POR = 9.7, 95% CI: 3-33), and HIV infection (POR = 10.4, 95% CI: 4-29). The HIV seroincidence rate was 5.9 per 100 person-years. None of the IDU receiving methadone maintenance treatment (MMT) seroconverted whereas the HIV incidence was 8.5 among IDU not in MMT (P = 0.01).

CONCLUSIONS

The increased risk of HBV, HCV, and HIV infection among IDU who had shared syringes in prison warrants specific preventive action. The longitudinal data suggest that IDU in MMT have a lower risk of HIV infection.

Knowledge-based system ADNEXPERT to assist the sonographic diagnosis of adnexal tumors

ADNEXPERT is a knowledge-based system for the computer-assisted ultrasound diagnosis of adnexal tumors. In a case-based approach, ADNEXPERT used histopathologic and sonographic data from 2,290 adnexal tumors. After an ultrasound examination, the gynecologist interacts with the system. A maximum of 15 questions are posed; all but one question (age) relate to the sonographic findings. The help system gives online access to an ultrasound image library. Once the dialogue is complete, ADNEXPERT assesses the adnexal tumor pathology and makes a histological classification. A certainty factor (CF) model is used for knowledge representation. The CFs of the knowledge base are computed from the case database. During system evaluation, the accuracy of ADNEXPERT was tested by 69 new adnexal tumor cases, for which verified histopathological diagnoses were available. ADNEXPERT accurately assessed pathology in 49 cases (71%); in 10 cases (14%) correct indications to pathology were given; no diagnostic hints were attained in 2 cases (3%); and 8 cases (12%) were falsely diagnosed. Based on the positive results of the evaluation, ADNEXPERT will be tested under clinical conditions.

[Referral to a clinical-genetic center for genetic counseling in mental disorders]

OBJECTIVE

Evaluation of the genetic counselling for psychiatric disorders in a clinical genetic service.

DESIGN

Retrospective.

SETTING

Clinical Genetic Service Rotterdam, the Netherlands.

METHOD

Evaluation of the psychiatric genetic counselling during the period 1985-1992 (n = 49).

RESULTS

Psychiatric disorders were the indication for genetic counselling in 1%. A minority of the consultants were referred by the psychiatrist. The most common question was the risk of future children becoming affected by a psychiatric disorder already present in the family. The male-female ratio was about one for the whole group of consultants. Affected relatives were significantly more frequent in the woman's family than in the man's. The average number of affected individuals in a family was 3.6.

CONCLUSION

Genetic counselling for psychiatric disorders in a clinical genetic service is requested infrequently considering the frequency of these problems. This may be related to a lack of need for information and counselling in potential consultants or to adequate information by treating physicians, but also to insufficient recognition by general practitioners and psychiatrists of questions patients and their family have.