Uniquely low stable iron isotopic signatures in deep marine sediments caused by Rayleigh distillation

Dissimilatory iron reduction (DIR) is suggested to be one of the earliest forms of microbial respiration. It plays an important role in the biogeochemical cycling of iron in modern and ancient sediments. Since microbial iron cycling is typically accompanied by iron isotope fractionation, stable iron isotopes are used as tracer for biological activity. Here we present iron isotope data for dissolved and sequentially extracted sedimentary iron pools from deep and hot subseafloor sediments retrieved in the Nankai Trough off Japan. Dissolved iron (Fe(II)_aq) is isotopically light throughout the ferruginous sediment interval but some samples have exceptionally light isotope values. Such light values have never been reported in natural marine environments and cannot be solely attributed to DIR. We show that the light isotope values are best explained by a Rayleigh distillation model where Fe(II)_aq is continuously removed from the pore water by adsorption onto iron (oxyhydr)oxide surfaces. While the microbially mediated Fe(II)_aq release has ceased due to an increase in temperature beyond the threshold of mesophilic microorganisms, the abiotic adsorptive Fe(II)_aq removal continued, leading to uniquely light isotope values. These findings have important implications for the interpretation of dissolved iron isotope data especially in deep subseafloor sediments.

Cumulative changes in weight but not fluid volume balances reflect fluid accumulation in ICU patients

BACKGROUND

The cumulative fluid balance of critically ill patients seems to be an outcome-relevant variable. However, there are no validated data for their reliability calculated for longer (> 5 days) periods of time.

METHODS

All ICU patients ≥ 18 years, with an ICU stay ≥ 5 days and a body weight ≤ 195 kg were evaluated from 1 January 2013 to 31 December 2013. Daily standardized weighing was performed using bed-integrated scales simultaneously with the daily 24-h fluid balance. Simultaneously, a fluid balance without and with insensible perspiration (10 ml/kg/day) was calculated for each 24 h. Primary endpoint: difference between cumulative fluid balance and body weight changes at the day of transfer to the normal ward or the day of death in the ICU, respectively, in each patient. All data are presented as medians with interquartile ranges (IQR) with 25 and 75 percentiles (IQR/25/75) unless otherwise noted.

RESULTS

One hundred and six critically ill patients were evaluated; 82 survivors and 24 nonsurvivors. Cumulative 24-h fluid balances rose continuously while body weight decreased over time. Correction of cumulative fluid balances for insensible perspiration (10 ml/kg/day) also did not match with body weight changes. Only survivors had a significant loss in body weight -1.8 (27.5/-6.1/1.0) kg.

CONCLUSIONS

Assuming that changes in body weight reflect changes in whole body water content cumulative daily fluid volume balances without or with correction for insensible water loss are not useful for estimating cumulative fluid balance of ICU patients. Survivors but not nonsurvivors had a significant loss of weight over time.

Review of 103 Swedish Healthcare Quality Registries

BACKGROUND AND OBJECTIVES

In the past two decades, an increasing number of nationwide, Swedish Healthcare Quality Registries (QRs) focusing on specific disorders have been initiated, mostly by physicians. Here, we describe the purpose, organization, variables, coverage and completeness of 103 Swedish QRs.

METHODS

From March to September 2013, we examined the 2012 applications of 103 QRs to the Swedish Association of Local Authorities and Regions (SALAR) and also studied the annual reports from the same QRs. After initial data abstraction, the coordinator of each QR was contacted at least twice between June and October 2013 and asked to confirm the accuracy of the data retrieved from the applications and reports.

RESULTS

About 60% of the QRs covered ≥80% of their target population (completeness). Data recorded in Swedish QRs include aspects of disease management (diagnosis, clinical characteristics, treatment and lead times). In addition, some QRs retrieve data on self-reported quality of life (EQ5D, SF-36 and disease-specific measures), lifestyle (smoking) and general health status (World Health Organization performance status, body mass index and blood pressure).

CONCLUSION

Detailed clinical data available in Swedish QRs complement information from government-administered registries and provide an important source not only for assessment and development of quality of care but also for research.

[Information on early detection of colorectal cancer: development of an information module for the women's health portal of the Federal Center for Health Education (BZgA)]

Colorectal cancer is the second most prevalent cancer in Germany. The governmental program for early detection of colorectal cancer intends to increase the chances of recovery by identifying colorectal cancer in an early, more treatable stage. Citizens need quality-assured, balanced, and target-group-specific information to be able to make an informed decision. On the basis of the current state of research, of extensive studies, and of expert and user interviews, the Federal Center for Health Education (BZgA) developed an information module on"early detection of colorectal cancer" for the women's health portal of the BZgA. The information module contains information on colorectal cancer, on the governmental program for early detection, as well as on the program's benefits and risks. The information offered is intended to be up to date and is approved by experts. The BZgA approves the quality of this information using methods of process and outcome evaluation.

Seizures during antidepressant treatment in psychiatric inpatients--results from the transnational pharmacovigilance project "Arzneimittelsicherheit in der Psychiatrie" (AMSP) 1993-2008

RATIONALE

There is little clinical data available about seizure rates in psychiatric inpatients, and there are no studies with reference data to the frequencies of antidepressant (AD) use for this important clinical population.

OBJECTIVE

This study investigates seizure rates during AD treatment in psychiatric inpatient settings, drawn from the transnational pharmacovigilance programme Arzneimittelsicherheit in der Psychiatrie (AMSP) in relation to the known frequencies of ADs used in the participating clinics. Comparisons are made to former publications and their limitations.

RESULTS

Seventy-seven cases were identified with grand mal seizures (GMS) during AD treatment between 1993 and 2008, with a total number of 142,090 inpatients under surveillance treated with ADs in the participating hospitals. The calculated overall rate of reported seizures of patients during AD treatment in this collective is 0.05 % for ADs imputed alone or in combination with other psychotropic drug groups and 0.02 % when only ADs were given and held responsible for GMS. The patients receiving tri- or tetracyclic ADs (TCAs) had a 2-fold risk to develop a seizure as compared to the overall average rate in this sample. In 11 cases, there was only one AD imputed--the majority of these cases (9/11) were TCA. Monotherapy with selective serotonin reuptake inhibitors (SSRI) or dual serotonin and noradrenaline reuptake inhibitors (SNRI) were never imputed alone in this sample.

CONCLUSIONS

The results of the study favour the assumption that SSRIs, noradrenergic and specific serotonergic antidepressants (NaSSA) and dual SNRI might be more appropriate than TCAs for the treatment of psychiatric patients with an enhanced seizure risk.

Oocyte zona birefringence intensity is associated with embryonic implantation potential in ICSI cycles

A retrospective study recently showed that oocytes presenting with a high birefringence of the inner zona layer were more often associated with conception cycles. To further investigate these findings, a prospective study was conducted between September 2005 and September 2006 including intracytoplasmic sperm injection (ICSI) cycles presenting with at least two embryos for transfer. Using a polarization imaging system, oocytes were classified prior to ICSI treatment as having either a high zona birefringence (HZB) or a low zona birefringence (LZB) of the zona pellucida. Using zona birefringence as the only selection criterion, two fertilized oocytes, preferably derived from HZB oocytes, were selected for further culture and transfer. The required criteria were met by 135 ICSI cycles (124 patients; 34.9 +/- 4.1 years of age). Embryos for transfer were used in 20 cycles derived from HZB/HZB oocytes, in 50 cycles from HZB/LZB oocytes and in 65 from LZB/LZB oocytes. The corresponding implantation (P < 0.025), pregnancy (P < 0.005) and live birth (P < 0.025) rates were significantly different between HZB/HZB and HZB/LZB versus LZB/LZB group. Embryo development was superior in embryos derived from HZB oocytes. This study concludes that oocyte zona birefringence is a good selection criterion and a good predictive criterion for embryo implantation potential.

Sickness behavior of rats with abdominal sepsis can be improved by antibiotic and G-CSF prophylaxis in clinic modeling randomized trials

BACKGROUND AND AIM

In clinical sepsis research nearly all immune-modulators have demonstrated no benefit in regard to the 28-day mortality rate. Other endpoints such as quality of life have become more attractive, but clinically relevant animal models analyzing an equivalent to quality of life by measurement of sickness behavior are extremely rare. The concept of clinic modeling randomized trials was used in an animal trial to model clinical complexity and conditions of a randomized clinical trial.

METHODS

80 adult male Wistar rats were randomly assigned to (1) control: anesthesia and sham operation, (2) sepsis: laparotomy and peritoneal infection with human stool bacteria, (3) sepsis with antibiotic prophylaxis: cefuroxime/metronidazole and (4) sepsis with antibiotic plus a cytokine prophylaxis with granulocyte-colony stimulating factor (GCSF). Endpoints were physiological and behavioral parameters.

RESULTS

The combination of antibiotics plus G-CSF was most effective in reducing mortality. All infected animals showed reduced open field activity acutely after infection, and recovery was improved during the 9 day follow-up in rats with prophylactic treatments. In the social interaction test, but not in the elevated plus-maze anxiety test, prophylaxis was also efficient, especially with antibiotics and G-CSF.

CONCLUSIONS

The results show that improving sickness behavior in septic rats with G-CSF plus antibiotics may be a promising approach.

165RE-EXPANSION AND QUALITY OF SPLIT BOVINE EMBRYOS IN VITRO

Transferring split bovine embryos results in a higher number of calves born per embryo. In addition to generating genetically identical progeny, biopsies can be made for molecular biological analyses. We aimed to determine the effect of splitting ratio on the in vitro development of Day 7 (164 to 168h post insemination) IVP bovine embryos. The inner cell mass (ICM) and trophoblast cells were split in three ratios (50:50, 60:40 and 70:30) with a Beaver microblade (Becton Dickinson, N.J., USA.) fixed to a micromanipulator under an inverse microscope at 100 X (Leica, Bensheim, Germany). Split blastocysts were cultured singly in 50μL drops of CR1aa medium at 39°C under 5% CO2 in a moisture-saturated atmosphere. After 1 and 2h culture, the morphology was assessed by judging the shape of the embryos and re-development of the blastocoel. On Day 8 (after 22h culture), the shape of the blastocysts, development of the ICM, blastocoel, proportion of degenerated cells and embryos and re-expanded blastocysts were recorded. Embryos were stained with propidium iodide and Hoechst 33258 for cell counting. The re-expansion status of Group A (50, 60 and 70%) and B (50, 40 and 30%) embryos after 1 and 2h and their quality after 22h culture (1: excellent=&lt;10% degenerated cells, well-defined ICM; 2: fair=&lt;20% degenerated cells) are shown in Table 1. With regards to Group A split blastocysts, a higher (P&lt;0.05) percentage of embryos that re-expanded after 1 and 2h and which yielded Quality 1 and 2 embryos suitable for embryo transfer was observed with the 60% and 70% than with demi-embryos. There were significant differences (P&lt;0.05) between all split blastocysts in Group B after 1h culture. The 30% split embryos showed the lowest re-expansion rate and quality of embryos after 2h and 22h culture, respectively. No differences (P&lt;0.05) were seen in the ratio of the ICM to the total number of cells in both Group A and B. This study showed that the ratio in which blastocysts were split had a significant effect on re-expansion and quality but not on the number of cells. Table 1

[Concepts in early planning for vocational rehabilitation in schizophrenia patients during acute care]

The particular relevance of employment for financial independence, acquisition of social skills and, hence, an increase in self-confidence is undeniable, and has for several years now been increasingly considered an essential component of care notably in psychiatric disorders. Vice versa, unemployment is deemed a potential risk factor with regard to poorer therapeutic response and social integration as well as a higher incidence of crises in persons with mental illness. Schizophrenia is among the psychiatric disorders very often resulting in unemployment and subsequent early pensioning. Planning for vocational rehabilitation early-on during acute care therefore is considered of greatest importance especially in this patient group. This article gives a brief overview of the main concepts drawn on in preparing the vocational rehabilitation of patients with Schizophrenia, focussing in particular on their relevance for daily practice and the possibilities for evaluating their effectiveness.

Changing sex ratio in acute coronary heart disease: data from Swedish national registers 1984-99

OBJECTIVES

To examine trends in sex ratios for different manifestations of coronary disease.

DESIGN

National Swedish registers on hospital discharges and cause-specific deaths were used to calculate age- and sex-specific trends and sex ratios for coronary admissions and deaths.

SETTING

Nineteen Swedish counties, average population 4.8-5.1 million in the investigated age groups.

SUBJECTS

All patients aged 25-84 years with first hospital admissions or deaths as a result of coronary heart disease in 1984-99, in total 432,871 cases.

MAIN OUTCOME MEASURES

Ratio men/women and rates (per 100,000) of acute myocardial infarction (AMI), acute admissions for angina and total of all acute admissions for any coronary disease.

RESULTS

Below age of 65 years AMI incidence decreased more for men than for women and rates of acute admissions for angina increased more in women than in men. In men and women above 65 years trends were almost identical. In 1984-87 the ratio men/women with respect to myocardial infarction was 5.6 at age 25-44 years, but decreased to 3.7 in 1996-99. Corresponding sex ratios for angina decreased from 3.2 to 1.8 and for total coronary heart disease from 4.7 to 2.8. Amongst men and women aged 45-54 years, the sex ratio with respect to myocardial infarction decreased from 5.6 to 4.1, for angina from 2.4 to 1.7 and for total acute coronary disease from 4.2 to 2.7. Ratios men/women decreased less at higher ages and remained unchanged throughout the period in the oldest age group.

CONCLUSIONS

Overall, we found decreasing sex ratios at ages below 65, but above age 65 years trends in men and women were similar. These developments could be due to changing criteria for admission and diagnosis, but true differences in the clinical manifestation of coronary disease, possibly in response to secular trends in risk factor levels, cannot be excluded.

Neurological sequelae in children born after in-vitro fertilisation: a population-based study

BACKGROUND

There is an absence of population-based long-term studies on the risk of neurological sequelae in children born after in-vitro fertilisation (IVF). Our aim was to compare the frequency of such problems between IVF-born children and controls.

METHODS

We did a population-based retrospective cohort study in which we compared development of neurological problems in 5680 children born after IVF, with 11360 matched controls. For 2060 twins born after IVF, a second set of controls (n=4120), all twins, were selected. We obtained data on neurological problems from the records of the Swedish habilitation centres.

FINDINGS

Children born after IVF are more likely to need habilitation services than controls (odds ratio 1.7, 95% CI 1.3-2.2). For singletons, the risk was 1.4 (1.0-2.1). The most common neurological diagnosis was cerebral palsy, for which children born after IVF had an increased risk of 3.7(2.0-6.6), and IVF singletons of 2.8 (1.3-5.8). Suspected developmental delay was increased four-fold (1.9-8.3) in children born after IVF. Twins born after IVF did not differ from control twins with respect to risk of neurological sequelae. Low-birthweight and premature infants were more likely to need habilitation than fullterm babies. Maternal age did not affect risk.

INTERPRETATION

Our study suggests that children born after IVF have an increased risk of developing neurological problems, especially cerebral palsy. These risks are largely due to the high frequency of twin pregnancies, low birthweight, and prematurity among babies born after IVF. To limit these risks, we recommend that only one embryo should be transferred during IVF.

Structure and expression of Xenopus tropicalis BMP-2 and BMP-4 genes

The Xenopus tropicalis BMP-2 and BMP-4 genes have been cloned and sequenced. A comparison with the corresponding genes from X. laevis reveals that the BMP-4 genes are conserved at a higher extent than the BMP-2 genes. This is especially evident for the intron sequences, but is also reflected by the exon sequences. While the amino acids of X. tropicalis and X. laevis BMP-4 proteins diverge at about 4%, those of BMP-2 proteins diverge at about 7%. By reverse transcriptase polymerase chain reaction analyses and whole mount in situ hybridizations, we demonstrate the temporal and spatial expression patterns of X. tropicalis BMP-2 and BMP-4 genes. BMP-2 is found to be expressed maternally, and later in development, in migrating heart progenitor cells as well as in the final heart, within the pineal gland and the olfactory placodes. BMP-4 is zygotically activated within the ventral marginal zone and later found in the eye, the otic vesicle, the heart and within blood islands. Although the overall patterns are very similar to those found in X. laevis, there is some distinct difference which might result from the accelerated development in X. tropicalis.

The Golgi matrix protein GM130: a specific interacting partner of the small GTPase rab1b

To detect specific partners of the small Golgi-localized GTPase rab1b we generated rab1b mutants and used them as bait proteins in yeast two-hybrid screens. We isolated several specifically interacting clones. Two of them encode large protein fragments highly homologous to rat GM130 and to human Golgin95. The full-length human GM130 cDNA was cloned and its interaction with rab1b was characterized in detail by yeast two-hybrid and in vitro binding assays. Here we report for the first time that the rab1b protein interacts specifically with GM130 in a GTP-dependent manner and therefore needs the hypervariable regions of the N- and C-termini. We mapped the rab1b binding site of GM130 and provide evidence that it is different to the previously described p115 and Grasp65 binding sites of the GM130 protein.

Bacterial populations and processes involved in acetate and propionate consumption in anoxic brackish sediment

Bacterial populations and pathways involved in acetate and propionate consumption were studied in anoxic brackish sediment from the Grosser Jasmunder Bodden, German Baltic Sea. Uptake of acetate and propionate from the porewater was studied using stable carbon isotope-labeled compounds. Labeled acetate was not produced as an intermediate during propionate uptake experiments, and propionate consumption was not affected by the addition of acetate. In parallel, incorporation of labeled acetate and propionate into phospholipid-derived fatty acids (PLFA) was studied to indicate bacterial populations involved in the consumption of these substrates. The (13)C-acetate label was mainly recovered in even-numbered PLFA (16:1omega7c, 16:0 and 18:1omega7c). In contrast, primarily odd-numbered PLFA (a15:0, 15:0, 17:1omega6 and 17:0) and the even-numbered i16:0 were labeled after incubation with (13)C-propionate. Although single PLFA labeled with propionate are commonly found in sulfate reducers, the complete PLFA-labeling pattern does not resemble any of the know strains. However, the acetate-labeling pattern is similar to Desulfotomaculum acetoxidans and Desulfofrigus spp., two acetate-consuming, sulfate reducers. In conclusion, our data suggest that acetate and propionate were predominantly consumed by different, specialized groups of sulfate-reducing bacteria.

Sex differences in survival after myocardial infarction in Sweden; data from the Swedish National Acute Myocardial Infarction Register

AIMS

Women, particularly younger women, hospitalized with acute myocardial infarction have been found to have poorer prognosis than men. A large proportion of deaths due to myocardial infarction, however, occur in the pre-hospital phase. We set out to analyse age-specific sex differences in survival after myocardial infarction at different time intervals from the onset of acute myocardial infarction, including pre-hospital deaths and 1-year overall survival.

METHODS AND RESULTS

The National Acute Myocardial Infarction Register in Sweden was used to analyse age-specific sex differences in mortality outside hospital, 28-day mortality and 1-year mortality in 353 905 cases occurring between 1987 and 1995 in Swedish men and women aged 30 to 89 years. Overall, one in four of all myocardial infarction victims died outside hospital. At all ages, except in individuals younger than 50 years, men had higher pre-hospital mortality. The odds of dying within 28 days for women below 50 years of age, compared to men, was 1.84 (1.56--2.18) in hospitalized patients and 1.31 (1.18--1.46) in all infarction patients. Above the age of 65, in the total population with myocardial infarction, women had a better prognosis, with odds ratios ranging from 0.83 to 0.89. In patients surviving the first 28 days, 4.0% of the women and 2.9% of the men below the age of 50 were dead within a year after the infarction, odds ratio 1.37 (1.06--1.76). This excess mortality was mainly due to diabetes and non-cardiac causes. Only women younger than 50 years had a significantly poorer overall 1-year survival than men of the same age. At the age of 70 or more, women had a small survival advantage.

CONCLUSION

In the total acute myocardial infarction population, only women under 50 years of age have a consistently worse prognosis than men. Much of the excess mortality in young women seems to be associated with diabetes.

Activin A signaling directly activates Xenopus winged helix factors XFD-4/4', the orthologues to mammalian MFH-1

We investigated the Xenopus winged helix gene XFD-4, its cDNA, and a pseudoallelic cDNA, termed XFD-4', representing Xenopus orthologues to chicken CWH-2 and mammalian MFH-1. XFD-4/4' genes are activated after midblastula transition in dorsolateral mesoderm but not within the dorsal lip. Later, expression is found in two segmented lines of cells bordering the somites, in head mesenchyme, in ventral abdominal muscle, and in the tail tip. Smad2 RNA injection leads to ectopic expression of XFD-4'. Since activation is also observed in activin A treated animal cap explants in the presence of cycloheximide, XFD-4/4' genes represent direct targets of activin signaling. Note that the future nomenclature for XFD-4 will be FoxC2a and for XFD-4' will be FoxC2b (Fox Nomenclature Committee).

[Trial employment: a provisional work setting for psychiatric patients]

OBJECTIVE

This study investigates the effects of probationary work for psychiatric patients in community-based small businesses during their inpatient or day care.

METHODS

Patients were evaluated for working capacity, psychopathology, motivation for work and patient satisfaction (n = 69).

RESULTS

The results confirm a high degree of acceptance of this approach as well as significant improvements on various clinical scales such as the Brief Psychiatric Rating Scale (BPRS), the Beck Depression Inventory (BDI), the Global Assessment of Functioning Scale (GAF), choice reaction time (Wiener Determinationsgerät, WDG), attention (Revisionstest) and self-rating of work-relevant skills.

CONCLUSIONS

This approach, with its complex demand characteristics, may be an effective alternative to occupational therapy, at least for small therapeutic units.

Characterization of a subfamily of related winged helix genes, XFD-12/12'/12" (XFLIP), during Xenopus embryogenesis

The fork head domain family of genes defines a growing group of proteins that serve important regulatory functions in pattern-forming events of both invertebrates and vertebrates. Here we add three closely related, novel members to this family in Xenopus laevis, termed XFD-12, XFD-12' and XFD-12". All three genes reveal indistinguishable expression patterns during Xenopus embryogenesis. During gastrulation, XFD-12 type transcripts are detected exclusively in the superficial layer of cells within the Spemann organizer territory. In the open neural plate, XFD-12 type expression defines a row of cells located along the dorsal midline and destined to become the floor plate of the neural tube. After closure of the neural tube, XFD-12 type encoding mRNAs are only detected in the tailtip and a small area located at the midbrain/hindbrain boundary. Within the Spemann organizer and in the floor plate area, expression of XFD-12 type genes is only partially overlapping with XFD-1 expression.

Retrospective versus original information on physical and psychosocial exposure at work

OBJECTIVES

Retrospective exposure assessments are often performed in epidemiologic studies. The presence of an eventual misclassification, both nondifferential and differential, is debated but can rarely be investigated. The aim of this study was to compare self-reported information on the same physical and psychosocial work exposures with 25 years' difference.

METHODS

In 1969-1970 a survey of randomly chosen men and women in Stockholm county, concerning, among other things, work exposures, was undertaken. During 1993-1994, 280 subjects participated in a reexamination, regarding psychosocial and physical factors at work and musculoskeletal disorders. The questions were all formulated in the same way as in 1969-1970.

RESULTS

When self-reported information on work exposures, collected with a 25-year interval, was compared, acceptable, although not high, agreement was found for 3 out of 4 physical factors and for 4 out of 10 physical environmental factors. Questions measuring psychosocial load had somewhat lower agreement. Current exposure status influenced the memory of past exposures. Study subjects who reported low-back disorders at the reexamination tended to show a better agreement in their assessments of retrospective exposures than those without current symptoms. When relative risks from original and retrospective data were calculated, hardly any influence on the estimates due to that differential misclassification could be found. For persons with and without neck or shoulder symptoms no apparent differences in assessments were found.

CONCLUSIONS

Retrospective assessments of exposures at the workplace showed misclassifications to a certain degree. However, the influence of the misclassifications on the risk estimates was limited.

Genomic structure and embryonic expression of the Xenopus winged helix factors XFD-13/13'

We have isolated the gene, its corresponding cDNA and a closely related cDNA encoding the Xenopus winged helix factors XFD-13' and XFD-13, respectively. XFD-13/13' are regarded as pseudo-alleles and, based upon a comparison of sequences and genomic structures, represent the Xenopus orthologues to mammalian FREAC-1/HFH-8. XFD-13/13' genes are not transcribed during oogenesis, zygotic transcription starts at late gastrula/early neurula and transcripts persist throughout embryogenesis. Expression is found within head derived neural crest cells and the dorsolateral plate (DLP). At later developmental stages, cell populations of the DLP migrate to the ventral region but exclude the most posterior part. Since they are subsequently found to accumulate in vessel like structures, we suggest that these cells represent hematopoietic/endothelial progenitor cells.

Obstetric complications and the risk of schizophrenia: a longitudinal study of a national birth cohort

BACKGROUND

Numerous epidemiological studies found an increased risk of schizophrenia among persons exposed to various obstetric complications. The underlying mechanisms are unknown.

OBJECTIVE

To study specific risk factors, as well as sets of risk factors, representing 3 different etiologic mechanisms: (1) malnutrition during fetal life; (2) extreme prematurity; and (3) hypoxia or ischemia.

METHODS

In this longitudinal cohort study, information in the National Birth Register was linked to the National Inpatient Register. We followed up 507516 children born between 1973 and 1977 with regard to a diagnosis of schizophrenia between 1987 and 1995 (238 cases). By record linkage, we also had access to data on psychiatric illness in the mother. Occurrence of schizophrenia was measured by the Mantel-Haenszel test and logistic regression.

RESULTS

A number of specific risk factors were associated with an increased risk of schizophrenia. The relative risk (95% confidence interval) for preeclampsia was 2.5 (1.4-4.5); vacuum extraction, 1.7 (1.1-2.6); and malformations, 2.4 (1.2-5.1). In logistic regression models, we found that indicators of all 3 etiologic mechanisms were associated with increased point estimates of schizophrenia, although at lower risk levels. Preeclampsia, an indicator of fetal malnutrition, was the only risk factor with statistically significant increased risk after control for all potentially confounding factors.

CONCLUSION

This study supports the theory of an association between obstetric complications and schizophrenia. Although preeclampsia was the strongest individual risk factor, there was evidence of increased risk associated with all 3 etiologic mechanisms.

Dynamic redistribution of STAT1 protein in IFN signaling visualized by GFP fusion proteins

STAT proteins (signal transducers and activators of transcription) are a family of transcription factors which are used by many cytokines and cell growth factors for initiating gene expression. They are activated by tyrosine phosphorylation through the cytoplasmic domain of stimulated receptors. Upon phosphorylation STAT proteins dimerize, translocate to the nucleus and activate transcription by binding to specific recognition sites. Different cytokines activate different subsets of STATs and other signaling proteins. We have made use of green fluoresencent protein (GFP) fusion proteins to visualize the subcellular localization and trafficking of STAT1, STAT2 and p48 during interferon (IFN) stimulation and have analysed in detail STAT1-GFP trafficking in living cells. Analysis of GFP fusion proteins allowed the determination of time kinetics of subcellular trafficking in individual living cells. STAT1-GFP is indistinguishable from its wild-type protein displaying strong activity as transcriptional activator as well as the same time kinetics of transport to the nucleus and retreat to the cytoplasm. After prolonged exposure to IFN, STAT1-GFP is no longer retained in the nucleus and relocation to the cytoplasm is observed. Restimulation with the same type of IFN does not lead to repeated nuclear translocation of STAT1-GFP. STAT1 is not subject of inhibition, as restimulation with another type of IFN allows immediate reuse of previously activated STAT1-GFP. However, restimulation with the same type of IFN can be achieved when the primary stimulus is removed after a short induction period. This method of visualizing signal transduction reveals a considerable inhomogeneity with respect to the extent of STAT1-GFP shuttling within a clonal cell population, indicating that competence for full-blasted IFN response is restricted to a cellular subpopulation whereas other cells respond incompletely, retarded or not at all.

Risk factors for neck and upper limb disorders: results from 24 years of follow up

OBJECTIVES

To investigate associations between different potential risk factors, related and not related to work, and disorders of the neck and upper extremities occurring up to 24 years later.

METHODS

The study comprised 252 women and 232 men, Swedish citizens, 42-59 years of age and in a broad range of occupations. Information about potential risk factors was available from a former study conducted in 1969. Data on disorders of the neck, shoulder, and hand-wrist disorders were obtained retrospectively for the period 1970-93.

RESULTS

Risk factors were found to differ between the sexes. Among women over-time work, high mental workload, and unsatisfactory leisure time were associated with disorders in the neck-shoulder region. Interaction was found between high mental workload and unsatisfactory leisure time. Neck symptoms earlier in life were associated with recurrent disorders. Hand and wrist disorders were associated mainly with physical demands at work. Among men blue collar work and a simultaneous presence of high mental workload and additional domestic workload predicted disorders in the neck-shoulder region.

CONCLUSIONS

Factors related and not related to work were associated with disorders of the neck, shoulders, and hands and wrist up to 24 years later in life. These included factors related to working hours which previously have not been noted in this context. Interactions between risk factors both related and not related to work were commonly found.

No paternal effect on monozygotic twinning in the Swedish Twin Registry

Previous research has provided evidence for a genetic effect in monozygotic twinning, indicated by an increased risk for monozygotic women to have monozygotic offspring. However, since the biological mechanism for this trait is unknown, it is not clear if there exists a paternal inheritance. In this study we investigated twin pregnancies in offspring born in 1941-1996 to male twins in the Swedish Twin Registry and population controls born in 1926-1980. In total 4,225,331 offspring, of which 89,286 were twins, were studied. There was neither an increase in the probability for monozygotic men to have like-sexed twin offspring risk ratio (RR = 0.95; 95% CI = 0.77-1.13) nor an increase in the estimated number of monozygotic twin births. Thus, there is no evidence for a paternal effect on monozygotic twinning, suggesting that the gene(s) increasing the liability for division of the embryo are expressed in the mother and not in the fertilised egg.

Functional domains of interferon regulatory factor I (IRF-1)

Interferon (IFN) regulatory factors (IRFs) are a family of transcription factors among which are IRF-1, IRF-2, and IFN consensus sequence binding protein (ICSBP). These factors share sequence homology in the N-terminal DNA-binding domain. IRF-1 and IRF-2 are further related and have additional homologous sequences within their C-termini. Whereas IRF-2 and ICSBP are identified as transcriptional repressors, IRF-1 is an activator. In the present work, the identification of functional domains in murine IRF-1 with regard to DNA-binding, nuclear translocation, heterodimerization with ICSBP and transcriptional activation are demonstrated. The minimal DNA-binding domain requires the N-terminal 124 amino acids plus an arbitrary C-terminal extension. By using mutants of IRF-1 fusion proteins with green fluorescent protein and monitoring their distribution in living cells, a nuclear location signal (NLS) was identified and found to be sufficient for nuclear translocation. Heterodimerization was confirmed by a two-hybrid system adapted to mammalian cells. The heterodimerization domain in IRF-1 was defined by studies in vitro and was shown to be homologous with a sequence in IRF-2, suggesting that IRF-2 also heterodimerizes with ICSBP through this sequence. An acidic domain in IRF-1 was found to be required and to be sufficient for transactivation. Epitope mapping of IRF-1 showed that regions within the NLS, the heterodimerization domain and the transcriptional activation domain are exposed for possible contacts with interacting proteins.

Expression pattern of the winged helix factor XFD-11 during Xenopus embryogenesis

We have identified a cDNA encoding a novel Xenopus winged helix transcription factor termed as XFD-11 (Xenopus fork head domain). The DNA binding domain is most closely related to those of human or murine FREAC-3 (FKHL7/MF-1/FKH-1) proteins. The XFD-11 gene is activated at late blastula/early gastrula and transcription proceeds throughout embryogenesis. Early expression is found in ventral and lateral but not in dorsal mesoderm. At neurula stages, transcripts are found in posterior mesoderm except for the dorsal midline, and the gene is also transcribed at the lateral border of the neural plate and within anterior neuroectoderm. At later stages of development, transcripts are detected within the pronephros, the heart, within neural crest cells surrounding the eye, in the mandibular, hyoid and branchial arches, and within the tail.

Structural and functional analysis of the BMP-4 promoter in early embryos of Xenopus laevis

The Xenopus laevis BMP-4 gene shows an evolutionary conserved structure containing two coding exons and a leader exon. The transcripts which are detected after zygotic activation of the gene in ventral mesoderm of late blastula stage embryos do either contain the leader exon or begin within the first intron. Luciferase reporter/promoter studies revealed multiple elements being required for the activation and for the spatial control of transcription. These elements are located within the upstream region and within the second intron and they interact with a most proximal located basal promoter being indispensable for transcriptional activation. The auto-activatory capacity of BMP-4 is mediated by several enhancer elements being responsive not only to BMP-4 but also to BMP-2 signaling. BMP-2 might thus function as a natural activator of the BMP-4 gene in the early embryo. Since reporter activity obtained with distinct BMP-2/4 responsive promoter deletion mutants is simultaneously inhibited by the dominant negative BMP receptor as well as by chordin, we suggest that down-regulation of the BMP-4 gene by chordin results from an interference with the auto-regulatory loop at the level of protein-protein interactions.

Psychosocial and physical risk factors associated with low back pain: a 24 year follow up among women and men in a broad range of occupations

OBJECTIVES

To investigate the relation between psychosocial and physical factors at work, as well as conditions during leisure time, and low back pain (LBP) over 24 years.

METHODS

The study group consisted of 252 women and 232 men. From a previous study conducted in 1969, data on psychosocial and physical conditions and LBP were available. Data on LBP for 1971-93 were obtained retrospectively in 1993.

RESULTS

The prevalence of LBP in 1969 among women and men were 34% and 24%, the cumulative incidences of LBP during 1970-92 were 38% and 43%, and the prevalences in 1993 of having had LBP during the past 12 months were 44% and 39%, respectively. Monotonous work and few or unsatisfactory social contacts outside work were risk factors for LBP in 1969 among women. LBP in 1969 and dissatisfaction with leisure time were risk factors among both sexes for LBP in 1970-92. LBP in 1969 was a risk factor for LBP in 1993 among women and dissatisfaction with leisure time a risk factor among men. Interactions between few or unsatisfactory social contacts outside work, as well as dissatisfaction with leisure time, and several factors related to work were found to increase the risk of LBP among both sexes during the studied periods.

CONCLUSIONS

Conditions in leisure time exert a long term influence on LBP. In this study factors related to work had a long term effect only in interaction with leisure time factors.

Reproducibility of a questionnaire for assessment of present and past physical activities

OBJECTIVE

The aim of this study was to evaluate the reproducibility of a self-administered questionnaire about present and past physical activities at work and during leisure time.

METHODS AND DESIGN

The questionnaire, covering the period 1970-1993, comprised 12 questions on physical activities at work, and 12, with similar wording, for such activities in leisure time. There were also four questions on physical training. Two-week reproducibility (test-retest reliability) concerning the period 1970-1993 was analysed in a group of 44 subjects, and 1-year reproducibility, concerning current activities in 1993, was analysed in a second group of 123 subjects in relation to gender, age and low-back health.

RESULTS

Test-retest reliability calculated as intraclass correlation coefficients (ri) for physical activities at work (ri 0.41-0.98) exceeded that for leisure time and physical training activities (ri 0.33-0.68). Calculated correlations did not differ markedly between past and present activities. No distinct influence of gender or low back health on 1-year reproducibility was found, in contrast to a slight tendency towards higher reproducibility among subjects of 50 years and older compared with younger subjects.

CONCLUSIONS

Reproducibility of this questionnaire about physical activities at work showed no clear tendency to deteriorate regarding activities during the immediately preceding two decades. The questions about physical activities during leisure time have to be revised. Reliable retrospective information about physical activities in leisure time could perhaps not be collected by self-administered questionnaires and other methods, e.g. interview-based questionnaires, may be more suitable.

Regulation and function of SF/HGF during migration of limb muscle precursor cells in chicken

Limb muscles of vertebrates are derived from migratory dermomyotomal cells which emanate from a limited number of somites located adjacent to the developing limb buds. We have generated additional limb buds in chicken embryos by implantation of FGF-beads into the interlimb region in order to analyze whether these somites can be programmed to supply ectopic limbs with myogenic precursor cells. We show that migrating myogenic precursor cells are released from somites at the level of the newly formed limb, even when cell migration into the natural limb has been completed. The implantation of FGF beads in the lateral plate mesoderm rapidly induces SF/HGF expression. FGF beads implanted between HH stages 10 and 12 inhibit limb bud formation or shift the normal limb position. When an additional FGF bead was implanted at the original limb position at HH stage 15, SF/HGF expression was transiently induced to low levels without inducing a new limb. This demonstrates that the initial induction of SF/HGF by FGF does not require limb formation. Expression of SF/HGF during early limb bud stages was found in the entire developing bud and the adjacent lateral plate mesoderm with direct contacts to the lateral edge of the dermomyotome. Later, the SF/HGF expression domain retracts to a distal region below the apical ectodermal ridge. To investigate the role of SF/HGF in the migratory process, we implanted beads soaked in SF/HGF-alone or together with FGF into different locations of the developing chick embryo. In the experiments SF/HGF caused delamination of migratory cells from the dermomyotomal epithelium but no chemotactic attraction of migrating cells toward the SF/HGF source.

Musculoskeletal Symptoms among Computer-assisted Design (CAD) Operators and Evaluation of a Self-assessment Questionnaire

A self-administered questionnaire with questions related to the physical workload at video display units (VDUs) was tested for intra- and intermethod reliability among 36 men and 64 women working with research and documentation. The results showed an acceptable test-retest agreement. The answers to three questions were validated by direct measurements: the locations of keyboard and mouse on the table, and the distance between elbow and keyboard heights when working. The self-reported locations of keyboard and mouse showed good agreement with the direct measurements. A revised version of the questionnaire was used at a telecommunication laboratory to study work postures and musculoskeletal symptoms. Among CAD operators with identical work tasks, the women (n = 67) reported a higher prevalence of musculoskeletal symptoms than did the men (n = 475). Calculated prevalence rate ratios (women/men) for musculoskeletal symptoms ranged from 1.4 (low back) to 3.4 (left elbow). The CAD operators with at least 5.6 hours of mouse use/week (median) reported more symptoms in the arms than did the CAD operators with fewer hours' work. Operators with the mouse located outside an "optimal" area on the table reported more symptoms from shoulder joints (upper arms), shoulders (scapular), elbows, and wrists than did operators with the optimal mouse location. Thus, long hours of work with the mouse, as well as working with the mouse non-optimally located on the table, seemed to be risk factors for upper-limb symptoms.

Reproducibility of a questionnaire for assessment of physical load during work and leisure time. Stockholm MUSIC I Study Group. MUSculoskeletal Intervention Center

A self-administered questionnaire on physical load in lifetime occupational work, in present job, and in present leisure activities was tested for reproducibility with the test-retest method in 126 male and 217 female workers from 30 occupations. The questionnaire contained 92 questions and nine different response scales. The results indicated that questions concerning physical activity retrospectively and in the present job, vibrations in the present job, working postures involving the whole body, and questions concerning specific leisure activities (eg ball games, skiing, etc) seem to offer sufficient reproducibility to be worth testing for validity, at least at a 5-point ordinal level. Questions concerning working postures involving parts of the body, including awkward postures, and questions concerning manual materials handling seem to offer too poor reproducibility to be used in studies in which the aim is to quantify duration in proportions of a typical working day and frequencies in times per hour. Questions concerning level of physical activity and exertion in domestic work seem to offer too poor reproducibility to be used at a 5-point ordinal level. Gender, age, and musculoskeletal complaints did not influence the reproducibility to any great extent.

Repression of the macrophage scavenger receptor in macrophage-smooth muscle cell heterokaryons

Macrophage scavenger receptors mediate the uptake of chemically modified LDL in an unregulated manner, leading to massive intracellular accumulation of lipid and thus a foamy cellular morphology. In atherosclerotic lesions, foam cells originate not only from macrophages but also from smooth muscle cells, yet smooth muscle cells do not normally express scavenger receptors, and when exposed to chemically modified LDL in vitro, lipid accumulation does not occur. The mechanism of conversion of smooth muscle cells into foam cells in the arterial wall is thus still under discussion. To investigate whether direct interaction between macrophages and smooth muscle cells may be involved and to explore the effects of components of the two cell types on the expression of scavenger receptors, we report here experiments using somatic cell hybrids formed by fusion of the two cell types. Immunofluorescent labeling and confocal microscopic techniques were applied to investigate and measure (1) lipid accumulation (using Nile Red staining), (2) the binding and uptake of acetylated LDL (using 1,1'-dioctadecyl-1-3,3,3',3'-tetramethyl-indocarbocyanine perchlorate-labeled acetylated LDL), and (3) receptor expression (assessed using a specific anti-receptor antibody) in smooth muscle cell-macrophage heterokaryons, macrophage-macrophage homokaryons, smooth muscle cell-smooth muscle cell homokaryons, and unfused macrophages and smooth muscle cells. The results demonstrate that scavenger receptor expression becomes repressed in macrophage-smooth muscle cell heterokaryons but not in macrophage-macrophage homokaryons. One possible explanation for the observed repression would be the existence of a negative regulatory cytoplasmic factor produced by smooth muscle cells.

Etiologic fractions for physical work load, sports and overweight in the occurrence of coxarthrosis

OBJECTIVES

The aim of this study was to estimate the impact of physical work load, sports, and overweight on the incidence of coxarthrosis.

METHODS

A case-referent study was made of 239 male recipients of a hip prosthesis and 302 men randomly selected from the general population. Information was obtained by means of an interview and questionnaire. Exposures to physical work load and sports were measured as the cumulative number of hours of exposure up to 49 years of age. Overweight was measured as the estimated body mass index at 30 or 40 years of age.

RESULTS

The etiologic fraction related to the three risk factors was 40% for physical work load, 55% for sports, and 15% for overweight. Various measures of physical work load were considered, but they all proved to be correlated.

CONCLUSIONS

Approximately 80% of the idiopathic coxarthrosis was explained by the presence of the three risk factors.

Spatial and temporal transcription patterns of the forkhead related XFD-2/XFD-2' genes in Xenopus laevis embryos

Two novel fork head related cDNA sequences, termed XFD-2 and XFD-2', have been isolated from a Xenopus laevis gastrula stage cDNA library. XFD-2 and XFD-2' proteins share 88% sequence identity; a comparison of their fork head domains yields 96% identity. Such close homology suggests that the two genes represent pseudo-allelic variants of a common ancestor and probably arose by the ancient tetraploidization event in this species. Both genes are activated at midblastula transition. Main transcriptional activity is found during blastula and gastrula stages of development; thereafter, there is a gradual decrease of transcripts until somite segregation stages. Whole mount in situ hybridisation of blastula stage embryos reveals that the genes are initially transcribed within the animal hemisphere. Subsequently, we observe their transcription in a circumferential mode along the marginal zone, i.e., within the forming mesoderm. During gastrulation, these cells enter the blastoporus at the ventral, lateral and dorsal sites. At the end of gastrula and during neural stages transcripts are localized within somitogenic mesoderm, notochord, lateral and ventral mesoderm, neural floor plate, spinal cords and in the developing brain.

The FAR domain defines a new Xenopus laevis zinc finger protein subfamily with specific RNA homopolymer binding activity

The zinc finger motif defines a large superfamily of nucleic acid binding proteins. Conserved amino acid sequence elements associated with structurally variant zinc finger clusters define subfamilies of zinc finger proteins (ZFPs). The FAR domain (Finger Associated Repeats) is a novel type of repeat element found at the amino-terminus in a subfamily of Xenopus laevis ZFPs. Northern blot analyses of three different members of the FAR subfamily (XFO 6, XFO 9-3 and XFG 68) revealed that each of these genes is transcribed during oogenesis, embryogenesis and in all investigated tissues of adult animals thereby indicating a ubiquitous distribution of transcripts. All FAR-ZFPs tested so far have specific RNA homopolymer binding activity; they associate preferentially with poly(U). The FAR repeats possess limited primary sequence homology with a sequence in the nucleolar shuttling protein NO38, within a region that contains a casein kinase II phosphorylation site.

Characterization of protein kinase CK2 protein subunits and p53 in F9 teratocarcinoma cells in the absence and presence of cisplatin

The effect of cis-diaminedichloroplatinum(II) (cisplatin) on the induction of p53 and protein kinase CK2 activity was studied in the mouse teratocarcinoma cell line F9. Treatment of the cells with the chemotherapeutic agent cisplatin led to the detection of p53 3 h after addition of the drug. F9 cell extracts treated with and without cisplatin were analyzed by ion exchange chromatography for protein kinase CK2 alpha/beta subunits and p53 distribution. The following results were obtained: (a) in crude extracts of cisplatin-treated cells, CK2 activity was sometimes reduced by as much as 50%; (b) after separation by anionic exchange chromatography (MA7Q, BioRad) of the crude cellular extracts from cisplatin-treated cells, lower CK2 activity was found in the peak fractions confirming the results obtained with crude cellular extracts; (c) besides the detection of CK2 alpha subunit by immunostaining, we have detected, at a concentration of approximately 200 mM NaCl, a protein of approximately 46 kDa which reacted with the CK2 alpha-specific antibody. This fraction was devoid of CK2 activity; and (d) cisplatin-treated cells exhibited p53 protein, which was mostly eluting ahead but also partly together with CK2 holoenzyme.

Gene structure and alternative splicing of XFG 5-1, a X. laevis Zn finger protein with RNA homopolymer binding activity

We describe the fine-structure of the Xenopus laevis XFG 5-1 gene which codes for an RNA homopolymer binding Zn finger protein of the FAR (Finger Associated Repeat) subfamily. The gene contains six exons, i.e., a leader exon (I), four exons (II-V), each of them encoding one individual copy of the FAR repeat, and one exon (VI) encoding the linker as well as the complete multifinger-region of the corresponding protein. Isolation and characterization of distinct cDNAs revealed that primary transcripts are alternatively spliced, thereby leading either to mRNAs containing different copy numbers of the FAR repeat or, by utilization of an alternative splice acceptor site in front of exon VI, to an extension of the linker region between the FAR repeats and the multifinger domain. We also describe the fine-structure of a closely related gene, termed XFG 5-2, which is located downstream to the XFG 5-1 gene. The general structural organization in both genes is identical, but point mutations should give rise to a XFG 5-2 protein with a different number of Zn finger units.