High-dose treosulfan in patients with relapsed or refractory high-grade lymphoma receiving tandem autologous blood stem cell transplantation

This phase I/II study evaluated high-dose treosulfan in patients with high-grade lymphoma. In all, 21 patients (median age 51, 25-60 years) with primary refractory disease (n=3) or early (n=11) or late (n=7) relapse received DexaBEAM and one course etoposide for cytoreduction and PBPC mobilization. Subsequently, 16 patients received 30 g/m2 treosulfan and 140 mg/m2 melphalan, followed by autologous transplantation. Nine patients received a 2nd high-dose treatment (HDT) with 30 g/m2 treosulfan and 750 mg/m2 thiotepa. Recovery time to >1/nl leukocytes and >25/nl thrombocytes was 8.9 (range 8-11) and 11.9 (8-16) days after 1st and 9.6 (7-13) and 13 (9-19) days after 2nd HDT. Reversible grade 3 or 4 nonhematologic toxicities included mucositis (n=7), infection (n=7) and one episode of re-entry tachycardia. Two treatment-related deaths occurred after 2nd HDT. Since three dose-limiting toxicities occurred among nine patients receiving tandem HDT, 30 g/m2 of treosulfan was considered MTD in this setting. Patients with late compared to early relapse or refractory disease had a higher probability of CR (6/7 vs 3/14 patients, P=0.017) and overall survival (71 vs 21%, P<0.05, 24-49 months follow-up). In conclusion, high-dose treosulfan as major therapy component induces sustained complete remissions in relapsed high-grade lymphoma with acceptable toxicity.

[Guidelines for the sociomedical assessment of performance in patients suffering from chronic obstructive lung diseases (COPD) and bronchial asthma]

The following guidelines were developed for the medical assessment services of the German Federal Insurance Institute for Salaried Employees (BfA). Starting from day-to-day practice, criteria and attributes to guide decisions for a systematization of the sociomedical assessment of performance in chronic obstructive pulmonary diseases (COPD) and bronchial asthma were compiled. The guidelines aim at standardising the sociomedical assessment of performance and help to make the decision-making process more transparent - e. g. for the assessment of applications for decreased earning capacity benefits. Part I of the guidelines gives information on the classification of chronic obstructive pulmonary diseases (COPD) and bronchial asthma and on the number of pensions due to limited earning capacity. The guidelines summarise typical manifestations of chronic obstructive pulmonary diseases (COPD) and bronchial asthma and describe the necessary medical information for the sociomedical assessment of performance. Relevant assessment criteria for the medical history, clinical examination, and for diagnostic tests are illustrated.

[Validity of diagnoses of mental disorders by primary care physicians]

BACKGROUND AND OBJECTIVE

Even in young adult age, psychological disorders are highly prevalent. Family doctors and gynaecologists are the physicians most often consulted by young women. Hence, they have a special responsibility to diagnose psychiatric disorders and--if necessary--to refer to a specialist.

PATIENTS AND METHODS

In a prospective epidemiological study, 342 young women (between 18 and 25 years of age) were questioned two times with a structured interview (F-DIPS) designed for mental disorders. In the time period (1997 and 1998), we also investigated, by analysing personal health insurance data, primary-care physicians' diagnoses and payments for services rendered. The diagnoses were compared.

RESULTS

There was only a small accordance between F-DIPS and claimcards. Ambulant treating doctors diagnosed somatoform disorders in 28 % of the young women (F-DIPS: 3, 8 %). The F- DIPS found mostly phobic disorders (29 %) (claimcards: 6,1 %). A disorder-specific therapy was only rarely initiated. The treatment (psychotherapy and/or drug therapy) of women with psychiatric disorders appeared to be insufficient.

CONCLUSION

The study indicates that primary-care physicians should be urgently trained in psychiatric diagnostics und therapy.

[Guidelines for the sociomedical assessment of performance in patients suffering from discopathy or associated diseases]

The following guidelines were developed for the medical assessment services of the German Federal Insurance Institute for Salaried Employees (BfA). Starting from day-to-day practice, criteria and attributes to guide decisions for a systemisation of the sociomedical assessment of performance in discopathy or associated diseases were compiled. The guidelines aim at standardising the sociomedical assessment of performance and help to make the decision-making process more transparent -- e. g. for the assessment of applications for decreased earning capacity benefits. The guidelines summarise typical manifestations of discopathy or associated diseases and describe the necessary medical information for the sociomedical assessment of performance. Relevant assessment criteria for the medical history, clinical examination, and for diagnostic tests are illustrated. The assessment of the individual's capacity is outlined, taking occupational factors into account. Following the determination of dysfunctions the remaining abilities and disabilities, respectively, are deduced and compared with occupational demands. Finally, inferences are drawn regarding the occupational capacity of the individual. Guidelines for the sociomedical assessment of performance in coronary heart disease (CHD) have been published in Gesundheitswesen 2002, 64: 451-465.

Energy spectrum of 50-250 MeV/nucleon iron nuclei inside the MIR space craft

Stacks of CR-39 plastic nuclear track detectors were mounted inside the MIR spacecraft during the EUROMIR95 space mission for a period of 6 months. This long exposure time resulted in a large number of tracks of HZE-particles in the detector foils. All trajectories of stopping iron nuclei could be reconstructed by optimizing the etching conditions so that an automatic track measurement using image analysis techniques was possible. We found 185 stopping iron nuclei and used the énergy-range relation to calculate their energies at the stack surface. The measured spectrum of iron nuclei inside the MIR station is compared to results of model predictions considering the effect of the solar modulation for the mission period, the geomagnetic shielding effect for the MIR orbit and the shielding by material of the spacecraft walls and its instrumentation.

[Guidelines for the sociomedical assessment of performance in patients suffering from coronary heart disease (CHD)]

The following guidelines were developed for the medical assessment services of the German Federal Insurance Institute for Salaried Employees (BfA). Starting from day-to-day practice criteria and attributes to guide decisions for a systemisation of the sociomedical assessment of performance in coronary heart disease (CHD) were compiled. The guidelines aim at standardising the sociomedical assessment of performance and help to make the decision-making process more transparent - e.g. for the assessment of applications for decreased earning capacity benefits. The guidelines summarise typical manifestations of CHD and describe the necessary medical information for the sociomedical assessment of performance. Relevant assessment criteria for the medical history, clinical examination and for diagnostic tests - especially of myocardial functioning - are illustrated. The assessment of the individual's capacity is outlined, taking occupational factors into account. Following the determination of dysfunctions the remaining abilities and disabilities, respectively, are deduced and compared with occupational demands. Finally inferences are drawn regarding the occupational capacity of the individual.

Optimal hand locations for safe scaffold-end-frame disassembly

Overexertion and fall injuries comprise the largest category of injuries among scaffold workers. A significant portion of these injuries is associated with scaffold-end-frame dismantling tasks, which require both muscle strength and postural balance skills. The commonly used tubular scaffold end frame is 1.52-m wide x 2-m high and weighs 23 kg. Previous studies have indicated that a great muscle strength can be generated when scaffold workers placed their hands symmetrically at knuckle height. However, adequate postural stability can only be reached when the workers placed their hands at the chest or shoulder height, which is near to the height of scaffold-end-frame center-of-mass. A reasonable approach to solve this dilemma is to develop an assistive lifting device, such as a light-weight clip-and-lift bar, that allows workers to place their hands at the height of the center-of-mass of end frames and concurrently allows an optimal hand separation for them to generate an adequate maximum isometric muscle force to safely accomplish the task. This study was conducted to determine the optimal hand location for a conceptual assistive lifting device to mitigate potential postural imbalance while reducing overexertion hazards during scaffold disassembly. This location would be within a window defined by a vertical hand placement between shoulder height and knuckle height and by a horizontal hand separation distance of shoulder width to end-frame width. The whole-body maximum isometric strength of 54 construction workers was measured in nine symmetric scaffold-end-frame disassembly postures, defined by a combination of three vertical hand placements by three horizontal hand separation distances within the aforementioned window. The study apparatus include a computer-controlled data-acquisition system, a custom-fabricated scaffold fixture, and two Bertec force platforms. An analysis of variance showed that the interaction effect of vertical hand placement and hand separation on workers' maximum isometric strength was significant (p < 0.004). A hand location between elbow height and chest height with a hand separation distance of 46 cm (a conceptual, light-weight assistive bar) would allow workers to generate sufficient isometric strength (about twice that of the scaffold weight) to disassemble the typical 23 kg scaffolds while concurrently allowing them to mitigate the likelihood of postural imbalance.

Risk of disease in siblings of patients with hereditary hemochromatosis

BACKGROUND

Parents of hereditary hemochromatosis (HH) homozygote patients, who are predominantly HH heterozygotes, have been found to have an increased risk of colonic neoplasia, diabetes, stroke death, stomach cancer and leukemia. The health histories of siblings of HH patients are reported.

METHODS

Individuals homozygous for HH were mailed questionnaires concerning the health histories of their siblings. Spouses of the HH homozygotes were asked to complete accompanying questionnaires concerning their siblings. The frequencies of serious illness and, when specified, each reported disease were determined by zygosity, odds ratios and 95% confidence intervals estimated.

RESULTS

Data were available for 279 siblings known to be HH homozygotes (HHs), and 1,265 other siblings of HH patients, who are predominantly hemochromatosis heterozygotes (HHhet). Controls consisted of 1,338 spouse siblings in whom only the general population prevalence of HH homozygosity and heterozygosity existed. Odds ratios comparing HH strata to controls were elevated for serious illness (1.12 in HHhet, 1.71 in HHs), diabetes (0.78, 2.45), arthritis (2.10, 1.69), and hepatoma (1.06, 11.96).

CONCLUSIONS

There was a significant trend for increased risk of serious illness among siblings of HH patients with increasing exposure to the HH gene, especially for diabetes, arthritis and hepatoma.

Prevalence, incidence and stability of premenstrual dysphoric disorder in the community

BACKGROUND

Despite an abundance of clinical research on premenstrual and menstrual symptoms, few epidemiological data provide estimates of the prevalence, incidence, co-morbidity, stability and correlates of premenstrual dysphoric disorder (PMDD) in the community.

AIMS

To describe the prevalence, incidence, 12 co-morbidity factors and correlates of threshold and subthreshold PMDD in a community sample of young women.

METHODS

Findings are based on prospective-longitudinal community survey of 1488 women aged 14-24, who were followed-up over a period of 48 months (follow-up, N = 1,251) as part of the EDSP sample. Diagnostic assessments were based on the Composite International Diagnostic Interview (CIDI) and its 12-month PMDD diagnostic module administered by clinical interviewers. Diagnoses were calculated using DSM-IV algorithms, but daily ratings of symptoms, as required, were not available.

RESULTS

The baseline 12-month prevalence of DSM-IV PMDD was 5.8%. Application of the diagnostic exclusion rules with regard to concurrent major depression and dysthymia decreased the rate only slightly (5.3%). An additional 18.6 % were 'near-threshold' cases, mostly because they failed to meet the mandatory impairment criterion. Over the follow-up period only few new PMDD cases were observed: cumulative lifetime incidence was 7.4%. PMDD syndrome was stable across 48 months with < 10% complete remissions among baseline PMDD cases. The 12-month and lifetime co-morbidity rates were high (anxiety disorders 47.4%, mood disorders 22.9%; somatoform 28.4%), only 26.5 % had no other mental disorder. Particularly high odds ratios were found with nicotine dependence and PTSD. In terms of correlates increased rates of 4-weeks impairment days, high use of general health and mental health services, and increased rates of suicide attempts were found.

CONCLUSION

In this sample of adolescents and young adults, premenstrual symptoms were widespread. However, DSM-IV PMDD was considerably less prevalent. PMDD is a relatively stable and impairing condition, with high rates of health service utilization, increased suicidality and substantial co-morbidity.

beta-adrenergic receptor blockers restore cardiac calcium release channel (ryanodine receptor) structure and function in heart failure

BACKGROUND

beta-Adrenergic receptor blockade is one of the most effective treatments for heart failure, a leading cause of mortality worldwide. The use of beta-adrenergic receptor blockers in patients with heart failure is counterintuitive, however, because they are known to decrease contractility in normal hearts. The ryanodine receptor (RyR2) on cardiac sarcoplasmic reticulum is the key calcium release channel required for excitation-contraction coupling. In failing hearts, the stoichiometry and function of the RyR2 macromolecular complex is altered. Decreased levels of phosphatases (PP1 and PP2A) and hyperphosphorylation by protein kinase A result in dissociation of the regulatory protein FKBP12.6 and channels with increased open probability.

METHODS AND RESULTS

Here, we show that systemic oral administration of a beta-adrenergic receptor blocker reverses protein kinase A hyperphosphorylation of RyR2, restores the stoichiometry of the RyR2 macromolecular complex, and normalizes single-channel function in a canine model of heart failure.

CONCLUSIONS

These results may, in part, explain the improved cardiac function observed in heart failure patients treated with beta-adrenergic receptor blockers.

Domain mapping of human PEX5 reveals functional and structural similarities to Saccharomyces cerevisiae Pex18p and Pex21p

PEX5 functions as an import receptor for proteins with the type-1 peroxisomal targeting signal (PTS1). Although PEX5 is not involved in the import of PTS2-targeted proteins in yeast, it is essential for PTS2 protein import in mammalian cells. Human cells generate two isoforms of PEX5 through alternative splicing, PEX5S and PEX5L, and PEX5L contains an additional insert 37 amino acids long. Only one isoform, PEX5L, is involved in PTS2 protein import, and PEX5L physically interacts with PEX7, the import receptor for PTS2-containing proteins. In this report we map the regions of human PEX5L involved in PTS2 protein import, PEX7 interaction, and targeting to peroxisomes. These studies revealed that amino acids 1-230 of PEX5L are required for PTS2 protein import, amino acids 191-222 are sufficient for PEX7 interaction, and amino acids 1-214 are sufficient for targeting to peroxisomes. We also identified a 21-amino acid-long peptide motif of PEX5L, amino acids 209-229, that overlaps the regions sufficient for full PTS2 rescue activity and PEX7 interaction and is shared by Saccharomyces cerevisiae Pex18p and Pex21p, two yeast peroxins that act only in PTS2 protein import in yeast. A mutation in PEX5 that changes a conserved serine of this motif abrogates PTS2 protein import in mammalian cells and reduces the interaction of PEX5L and PEX7 in vitro. This peptide motif also lies within regions of Pex18p and Pex21p that interact with yeast PEX7. Based on these and other results, we propose that mammalian PEX5L may have acquired some of the functions that yeast Pex18p and/or Pex21p perform in PTS2 protein import. This hypothesis may explain the essential role of PEX5L in PTS2 protein import in mammalian cells and its lack of importance for PTS2 protein import in yeast.

Hepatocyte damage induced by carbon tetrachloride: inhibited lipoprotein secretion and changed lipoprotein composition

Changes of lipoprotein secretion and composition in response to CCl4 treatment were studied in monolayer cultures of rat primary hepatocytes. (1) CCl4 decreased secretion of very low density lipoproteins (VLDL) by about 85%, while high density lipoprotein (HDL) secretion was less affected (about 40%). The effect was concentration-dependent. (2) CCl4 significantly inhibited secretion of VLDL- and HDL-associated triglycerides and cholesterol esters. VLDL- and HDL-associated cholesterol was not affected, while secretion of phospholipids was increased. (3) Hepatocytes secreted the apolipoproteins B48, B100, E, C, and A-I. CCl4 reduced secretion of apoproteins associated with VLDL by almost 20%, and by about 75% when associated with HDL. The de novo synthesis of apolipoproteins was attenuated by CCl4. (4) CCl4 caused variations in the apolipoprotein composition in VLDL and HDL. CCl4 intoxication of the liver affected the morphology and/or function of the lipoproteins, which drastically impaired their ability to act as transport vehicles for lipids from the liver to the circulation.

Mechanism of carbon tetrachloride-induced hepatotoxicity. Hepatocellular damage by reactive carbon tetrachloride metabolites

CCl4-induced liver damage was modeled in monolayer cultures of rat primary hepatocytes with a focus on involvement of covalent binding of CCl4 metabolites to cell components and/or peroxidative damage as the cause of injury. (1) Covalent binding of 14C-labeled metabolites was detected in hepatocytes immediately after exposure to CCl4. (2) Low oxygen partial pressure increased the reductive metabolism of CCl4 and thus covalent binding. (3) [14C]-CCl4 was bound to lipids and to proteins throughout subcellular fractions. Binding occurred preferentially to triacylglycerols and phospholipids, with phosphatidylcholine containing the highest amount of label. (4) The lipid peroxidation potency of CCl4 revealed subtle differences compared to other peroxidative substances, viz., ADP-Fe3+ and cumol hydroperoxide, respectively. (5) CCl4, but not the other peroxidative substances, decreased the rate of triacylglycerol secretion as very low density lipoproteins. (6) The anti-oxidant vitamin E (alpha-tocopherol) blocked lipid peroxidation, but not covalent binding, and secretion of lipoproteins remained inhibited. (7) The radical scavenger piperonyl butoxide prevented CCl4-induced lipid peroxidation as well as covalent binding of CCl4 metabolites to cell components, and also restored lipoprotein metabolism. The results confirm that covalent binding of the CCl3* radical to cell components initiates the inhibition of lipoprotein secretion and thus steatosis, whereas reaction with oxygen, to form CCl3-OO*, initiates lipid peroxidation. The two processes are independent of each other, and the extent to which either process occurs depends on partial oxygen pressure. The former process may result in adduct formation and, ultimately, cancer initiation, whereas the latter results in loss of calcium homeostasis and, ultimately, apoptosis and cell death.

Development of potential iron chelators for the treatment of Friedreich's ataxia: ligands that mobilize mitochondrial iron

Friedreich's ataxia (FA) is a crippling neurodegenerative disease that is due to iron (Fe) overload within the mitochondrion. One therapeutic intervention may be the development of a chelator that could remove mitochondrial Fe. We have implemented the only well characterized model of mammalian mitochondrial Fe overload to examine the Fe chelation efficacy of novel chelators of the 2-pyridylcarboxaldehyde isonicotinoyl hydrazone (PCIH) class. In this model we utilize reticulocytes treated with the haem synthesis inhibitor succinylacetone which results in mitochondrial Fe-loading. Our experiments demonstrate that in contrast to desferrioxamine, several of the PCIH analogues show very high activity at mobilizing (59)Fe from (59)Fe-loaded reticulocytes. Further studies on these ligands in animals are clearly warranted considering their potential to treat FA.

Prevalence and epidemiologic correlates of atypical squamous cells of undetermined significance in women at low risk for cervical cancer

Our aim was to determine the prevalence and epidemiologic correlates of atypical squamous cells of undetermined significance (ASCUS) in a population at low risk for cervical cancer in Porto Alegre, Brazil. Sociodemographic data and gynecological and obstetrical history from 977 women screened at an outpatient clinic were recorded. Specimens were collected for Papanicolaou cervical cytology, colposcopy, and biopsy (if indicated). Sixty-two (6.3%) patients presented ASCUS, 21 (2.1%) presented low-grade squamous intraepithelial lesions, and 6 (0.6%) presented high-grade lesions. Presence of human papillomavirus (HPV) DNA in cervical cells (odds ratio (OR) = 1.57; confidence interval (CI) 95% = 1.11-2.23), history of HPV infection (OR = 3.12; CI 95% = 1.22-7.96), and becoming sexually active at 18 yr or younger (OR = 1.70; CI 95% = 1.15-2.51) were independently associated with ASCUS. ASCUS patients reported HPV infections and presented HPV DNA in cervical cells more often than did patients with normal cytology; therefore, they should be carefully monitored to ensure early detection of cancer precursor lesions and prevention of cervical cancer.

Is hereditary hemochromatosis a balanced polymorphism: an analysis of family size among hemochromatosis heterozygotes

BACKGROUND/AIMS

Hereditary hemochromatosis (HH) has a homozygote frequency of 0.5% and a heterozygote frequency of 13%, which suggests that hemochromatosis might be a balanced polymorphism. Evidence for this was sought by assessing reproductive success among hemochromatosis heterozygotes through determining their family size and incidence of miscarriage when compared to nongene carriers.

METHODOLOGY

A cohort was defined in which the exposure variable was heterozygosity for hereditary hemochromatosis. Heterozygotes were identified by mailing individuals homozygous for hereditary hemochromatosis questionnaires concerning the number of siblings born alive and the number of miscarriages suffered by their mothers (predominantly heterozygotes, or HHH). Spouses of the hereditary hemochromatosis homozygotes were asked to complete accompanying questionnaires concerning their mothers (CONT).

RESULTS

Five hundred and ninety-six responses were received from hereditary hemochromatosis homozygotes and 532 responses from spouses of the hereditary hemochromatosis homozygote respondents. The mothers of the hereditary hemochromatosis homozygote respondents had a mean family size of 3.699. The mothers of the unexposed spouse controls a mean family size of 3.639 (P = 0.66 by ANOVA). One hundred and twenty-three of the HHH mothers suffered a total of 201 miscarriages, whereas 94 of the CONT mothers suffered 147 miscarriages (P = 0.38 by ANOVA).

CONCLUSIONS

In this cohort, no evidence among hemochromatosis heterozygotes of reproductive advantage and therefore heterozygous advantage by this mechanism was seen.

Pathogenesis of carbon tetrachloride-induced hepatocyte injury bioactivation of CCI4 by cytochrome P450 and effects on lipid homeostasis

The CCl4-induced development of liver damage was studied in monolayer cultures of primary rat hepatocytes: (1) CCl4 caused accumulation of triglycerides in hepatocytes following cytochrome P450 induction with beta-naphthoflavone or metyrapone. Ethanol or a high dose of insulin plus triiodothyronine had the same effect. (2) CCl4 increased the synthesis of fatty acids and triglycerides and the rate of lipid esterification. Cholesterol and phospholipid synthesis from acetate was also increased. (3) CCl4 reduced beta-oxidation of fatty acids as assessed by CO2-release and ketone body formation. Hydrolysis of triglycerides was also reduced. (4) The content of unsaturated fatty acids in microsomal lipids was decreased by almost 50% after incubation with CCl4, while saturated fatty acids increased slightly. (5) CCl4 exerted a pronounced inhibitory effect on the exocytosis of macromolecules (albumin), but did not affect secretion of bile acids from hepatocytes.

Frataxin: its role in iron metabolism and the pathogenesis of Friedreich's ataxia

Friedreich's ataxia (FA) is a severe neurodegenerative condition with an incidence of 1:50000 in the European population. In 97% of patients this disease is due to an intronic GAA triplet repeat expansion in the FRDA gene resulting in a marked decrease in its expression. The protein encoded by this gene is known as frataxin which is found within the mitochondrion. Upon deletion of the homologous gene (YFH1) in the yeast, there was an accumulation of iron (Fe) within the mitochondrion. When the YFH1 gene was reintroduced back into the yeast cell Fe was exported out of the mitochondrion and into the cytosol. Evidence that human frataxin is also involved in mitochondrial Fe-overload comes from studies in FA patients that have shown an accumulation of Fe within the heart. While the precise role of human frataxin remains to be determined, the molecule appears to be involved indirectly in regulating the export and/or import of mitochondrial Fe. The finding of mitochondrial Fe-overload suggests that the use of specific Fe chelators which can permeate the mitochondrion may have potential in the treatment of this disease.

Eosinophils maintain their capacity to signal and release eosinophil cationic protein upon repetitive stimulation with the same agonist

Eosinophils contain in their granules eosinophil cationic protein (ECP) and other basic proteins that have been implicated in immunity to parasites and pathophysiology of chronic allergic responses. In a model of eosinophil degranulation, we show that eosinophils release ECP upon short-term GM-CSF priming and stimulation with either platelet-activating factor (PAF) or the anaphylatoxin C5a, but not eotaxin. Restimulation with the same agonist (PAF or C5a) was unsuccessful as assessed by monitoring intracellular calcium concentration and ECP release. In contrast, upon an intermediate washing step, eosinophils rapidly transduced PAF and C5a signals followed by significant ECP releases. Ligand-binding studies demonstrated that only a proportion of PAF receptors is internalized upon cell stimulation and that washing of the cells removes the agonist from the cell surface. Upon repetitive stimulation, eosinophils with less than 50% of the original ECP content were obtained. Such eosinophils did not increase cellular ECP levels even in the presence of the eosinophil survival factor GM-CSF in overnight cultures. In vivo studies revealed that eosinophils always express detectable amounts of ECP under chronic inflammatory conditions. In conclusion, we have shown that eosinophils maintain their capacity to degranulate upon repetitive stimulation with the same agonist as long as the receptor is not occupied from a previous stimulation. The cellular content of ECP appears to be a no limiting factor in the case of repetitive stimulation, implying that mature eosinophils may not require a significant ECP resynthesis.

A comparison of different postures for scaffold end-frame disassembly

Overexertion and fall injuries comprise the largest category of nonfatal injuries among scaffold workers. This study was conducted to identify the most favourable scaffold end-frame disassembly techniques and evaluate the associated slip potential by measuring whole-body isometric strength capability and required coefficient of friction (RCOF) to reduce the incidence of injury. Forty-six male construction workers were used to study seven typical postures associated with scaffold end-frame disassembly. An analysis of variance (ANOVA) showed that the isometric forces (334.4-676.3 N) resulting from the seven postures were significantly different (p < 0.05). Three of the disassembly postures resulted in considerable biomechanical stress to workers. The symmetric front-lift method with hand locations at knuckle height would be the most favourable posture; at least 93% of the male construction worker population could handle the end frame with minimum overexertion risk. The static RCOF value resulting from this posture during the disassembly phase was less than 0.2, thus the likelihood of a slip should be low.

Influence of extremely low frequency electromagnetic fields on the swimming behavior of ciliates

Different species of ciliates (Paramecium biaurelia, Loxodes striatus, Tetrahymena thermophila) have been taken as model systems to study the effects of extremely low-frequency electromagnetic fields (50 Hz, 0.5-2.0 mT) on the cellular level. A dose-dependent increase in the mean swimming velocity and a decrease in the linearity of cell tracks were observed in all wild-type cells. In contrast, field-exposure did not increase the number of directional turns of the Paramecium tetraurelia pawn mutant (d4-500r), which is characterized by defective Ca2+-channels. The described changes indicate a direct effect of low frequency electromagnetic fields on the transport mechanisms of the cell membrane for ions controlling the motile activity of cilia.

Certification of a long-term sampling system for PCDFs and PCDDs in the flue gas from industrial facilities

AMESA (adsorption method for sampling of dioxins) is a fully automatic system for long term monitoring of dioxin emissions from industrial processes based on the adsorption method. The system has been tested and undergoing a certification procedure according to the German guidelines for certification of systems for continuous monitoring of special substances. The certification covered parameters such as disposability of the system, reproducibility of the results and comparability of the sampling method with German and European standard methods. Furthermore break through, blanks and sample storability were investigated. The results prove that AMESA is a state of the art sampling system for continuous monitoring of dioxin/furan emissions.

Neuroectodermal and endodermal expression of the ascidian Cdx gene is separated by metamorphosis

Ascidians are a group of invertebrate chordates that exhibit a biphasic life history, with chordate-specific structures developing during embryogenesis (dorsal neural tube and notochord) and metamorphosis (pharyngeal gill slits and endostyle). Here we characterize the expression of a caudal/Cdx gene homologue, Hec-Cdx, from the ascidian Herdmania curvata. Vertebrate Cdx genes are expressed at gastrulation and in the posterior of the developing neural tube and endoderm. Hec-Cdx expression is initiated at the earliest stages of gastrulation, with peaks in RNA abundance occurring first during neurulation and tailbud extension and then in 3- to 5-day-old juveniles. Hec-Cdx is expressed in a pair of cells in the anterior lip of the blastopore in the late gastrula which form the most posterior portion of the neural plate. During tailbud formation expression is maintained in and solely restricted to these cells. During metamorphosis expression is localized to the intestine of the juvenile. These data, along with data for the H. curvata Otx gene, suggest that the evolution of the novel ascidian biphasic body plan was not accompanied by a deployment of these genes into new pathways but by a temporal separation of tissue-specific expression.

Nck-interacting Ste20 kinase couples Eph receptors to c-Jun N-terminal kinase and integrin activation

The mammalian Ste20 kinase Nck-interacting kinase (NIK) specifically activates the c-Jun amino-terminal kinase (JNK) mitogen-activated protein kinase module. NIK also binds the SH3 domains of the SH2/SH3 adapter protein Nck. To determine whether Nck functions as an adapter to couple NIK to a receptor tyrosine kinase signaling pathway, we determined whether NIK is activated by Eph receptors (EphR). EphRs constitute the largest family of receptor tyrosine kinases (RTK), and members of this family play important roles in patterning of the nervous and vascular systems. In this report, we show that NIK kinase activity is specifically increased in cells stimulated by two EphRs, EphB1 and EphB2. EphB1 kinase activity and phosphorylation of a juxtamembrane tyrosine (Y594), conserved in all Eph receptors, are both critical for NIK activation by EphB1. Although pY594 in the EphB1R has previously been shown to bind the SH2 domain of Nck, we found that stimulation of EphB1 and EphB2 led predominantly to a complex between NIK/Nck, p62(dok), RasGAP, and an unidentified 145-kDa tyrosine-phosphorylated protein. Tyrosine-phosphorylated p62(dok) most probably binds directly to the SH2 domain of Nck and RasGAP and indirectly to NIK bound to the SH3 domain of Nck. We found that NIK activation is also critical for coupling EphB1R to biological responses that include the activation of integrins and JNK by EphB1. Taken together, these findings support a model in which the recruitment of the Ste20 kinase NIK to phosphotyrosine-containing proteins by Nck is an important proximal step in the signaling cascade downstream of EphRs.

The biologically active iron chelators 2-pyridylcarboxaldehyde isonicotinoylhydrazone, 2-pyridylcarboxaldehyde benzoylhydrazone monohydrate and 2-furaldehyde isonicotinoylhydrazone

In the crystal structures of the respective title compounds, C12H10N4O, C13H11N3O.H2O and C11H9N3O2, variations in the torsion angles of the aromatic pyridyl and benzoyl groups are observed, and the disposition of the heterocyclic aldehyde is shown to be influenced by the ring size of this group.