Chromosome shattering: a mitotic catastrophe due to chromosome condensation failure.

Chromosome shattering has been described as a special form of mitotic catastrophe, which occurs in cells with unrepaired DNA damage. The shattered chromosome phenotype was detected after application of a methanol/acetic acid (MAA) fixation protocol routinely used for the preparation of metaphase spreads. The corresponding phenotype in the living cell and the mechanism leading to this mitotic catastrophe have remained speculative so far. In the present study, we used V79 Chinese hamster cells, stably transfected with histone H2BmRFP for live-cell observations, and induced generalized chromosome shattering (GCS) by the synergistic effect of UV irradiation and caffeine posttreatment. We demonstrate that GCS can be derived from abnormal mitotic cells with a parachute-like chromatin configuration (PALCC) consisting of a bulky chromatin mass and extended chromatin fibers that tether centromeres at a remote, yet normally shaped spindle apparatus. This result hints at a chromosome condensation failure, yielding a "shattered" chromosome complement after MAA fixation. Live mitotic cells with PALCCs proceeded to interphase within a period similar to normal mitotic cells but did not divide. Instead they formed cells with highly abnormal nuclear configurations subject to apoptosis after several hours. We propose a factor depletion model where a limited pool of proteins is involved both in DNA repair and chromatin condensation. Chromosome condensation failure occurs when this pool becomes depleted.

[Pain-related disability in adolescents suffering from chronic pain. Preliminary examination of the Pediatric Pain Disability Index (P-PDI)]. / Schmerzbezogene Beeinträchtigung bei Jugendlichen mit chronischen Schmerzen. Erste Uberprüfung des Pediatric Pain Disability Index (P-PDI).

BACKGROUND: Pain-related disability affects many children and adolescents suffering from chronic pain and may exert an impact on all areas of their lives. Reduction of pain-related disability is, therefore, a fundamental aim of treatment; however, no validated means exist to assess pain-related disability in children and adolescents. The aim of this study was to translate the Pediatric Pain Disability Index (P-PDI) of Varni into German and to investigate its psychometric qualities. METHODS: Principal component and item analyses were conducted on outpatient (n=163) and inpatient samples (n=167) of adolescents suffering from chronic pain. Changes in pain-related disability 3 months after starting treatment were analysed in an outpatient sample of 110 adolescents. Correlations between pain-related disability, emotional variables and school absence as well as concordance with parents' ratings were investigated. RESULTS: The P-PDI is a one-dimensional assessment tool with sufficient reliability. There were significant correlations between pain-related disability and pain intensity and school absence but not with pain duration, fear and depression. Parents and adolescents ratings correlated significantly, but 57% of parents underestimated the pain-related disability of their children. CONCLUSION: There is now a validated German version of the P-PDI to measure pain-related disability in adolescents suffering from chronic pain, which can be used in studies investigating treatment effectiveness.

Destabilization of a protein helix by electrostatic interactions.

Electrostatic interactions between charged residues and the helix dipole in a protein were investigated by protein engineering methods. In ribonuclease T1, two surface-exposed acidic residues (Glu28 and Asp29) are located near the carboxyl terminus of the alpha-helix between residues 13 and 29. They were replaced, individually and in concert, by the uncharged amides Gln28 and Asn29, and the stabilities of the wild-type protein and its variants were determined as a function of pH. The effects of the two mutations are additive. Either one leads to a marginal destabilization by 0.7 kJ/mol at pH 2 but to a strong stabilization by about 3.2 kJ/mol at pH 7. This suggests that the deprotonations of Glu28 and Asp29 reduce the free energy of stabilization of folded ribonuclease T1 by about 4 kJ/mol each. This destabilization is probably caused by unfavorable electrostatic interactions of Glu28 and Asp29 with the negative end of the helix dipole. The activation energies for the unfolding of the different variants of ribonuclease T1 change in parallel with the differences in the thermodynamic stability when the pH is varied. This indicates that the unfavorable electrostatic interactions of Glu28 and Asp29 are lost very early in unfolding, and are not present in the activated state of unfolding.

Structural analysis of an RNase T1 variant with an altered guanine binding segment.

The ribonuclease T1 variant 9/5 with a guanine recognition segment, altered from the wild-type amino acid sequence 41-KYNNYE-46 to 41-EFRNWQ-46, has been cocrystallised with the specific inhibitor 2'-GMP. The crystal structure has been refined to a crystallographic R factor of 0.198 at 2.3 A resolution. Despite a size reduction of the binding pocket, pushing the inhibitor outside by 1 A, 2'-GMP is fixed to the primary recognition site due to increased aromatic stacking interactions. The phosphate group of 2'-GMP is located about 4.2 A apart from its position in wild-type ribonuclease T1-2'-GMP complexes, allowing a Ca(2+), coordinating this phosphate group, to enter the binding pocket. The crystallographic data can be aligned with the kinetic characterisation of the variant, showing a reduction of both, guanine affinity and turnover rate. The presence of Ca(2+) was shown to inhibit variant 9/5 and wild-type enzyme to nearly the same extent.

Herpesvirus saimiri transformed T cells and peripheral blood mononuclear cells restimulate identical antigen-specific human T cell clones.

Panels of human antigen-specific T cell clones (TCC) have been established by limiting dilution using Herpesvirus saimiri (HVS) subtype C transformed T cells as antigen presenting cells (APC). They showed antigen-specific proliferation when peripheral blood mononuclear cells (PBMC), HVS-transformed T cells and Epstein Barr Virus transformed lymphoblastoid B cell lines (EBV-LCL) were used as APC. All T cell clones were CD4+ and HLA class II restricted. For a detailed analysis, two panels of T cell clones specific for an epitope located in the N-terminus of the Merozoite Surface Protein 1 (MSP-1) of Plasmodium falciparum were established from the same founder T cell line using either PBMC or HVS-transformed T cells as APC. TCR analysis of the two panels of TCC demonstrated that the same founder cells could be propagated in both culture systems. Furthermore, no difference in the cytokine expression pattern or antigen processing and co-stimulatory requirements was observed between TCC established on PBMC or HVS-transformed T cells. Based on the finding that HVS-transformed T cells can replace PBMC as APC for isolation and propagation of antigen-specific TCC, a protocol was developed and successfully executed, which allows to establish and maintain vaccine-specific T cell clones from 20 ml of blood. This method might be particularly significant in clinical trials of immune intervention strategies.

Synergistic and antagonistic interactions between docetaxel and interferon-beta on growth of human breast cancer cells in vitro.

Docetaxel and interferon-beta (IFN-beta) were tested alone and in combination for their antiproliferative activity against the estradiol receptor (ER) positive MCF-7 and the ER negative MDA-MB231 breast cancer cell lines. Cell growth inhibition was determined after a 3 day incubation by the sulforhodamine B assay. The antiproliferative effects of the drug combinations were analysed using Berenbaum's hyperplane theorem to determine additive, synergistic and antagonistic effects. Docetaxel was found to be equally effective in inhibiting cell growth of both cell lines. On the other hand MCF-7 cells were more sensitive to the antiproliferative activity of IFN-beta than MDA-MB231 cells. At low docetaxel:IFN-beta molar concentration ratios a synergistic interaction was observed for MCF-7 cells, whereas an additive interaction was found for MDA-TMB231 cells. Higher molar ratios resulted in additive interactions on MCF-7 and antagonistic interactions on MDA-MB231 cells. MCF-7 cells seem to be more sensitive to treatment by the combination of docetaxel and IFN-beta than the MDA-MB231 cells. Therefore an ER positive breast carcinoma may possibly profit by the combination of docetaxel and IFN-beta, but further studies are necessary to clarify the therapeutic usefulness and optimal scheduling of the drug combination.

Synergistic interactions between interferon beta and carboplatin on SK-MEL 28 human melanoma cell growth inhibition in vitro.

Carboplatin and interferon beta (IFN beta) were tested alone and in combination for their antiproliferative activity on the human melanoma cell line SK-MEL 28 in vitro. Cells were incubated for 4 days in the presence of carboplatin (0.1 mM and 0.1 microM) and interferon beta (5 pM and 5 nM) and cell growth inhibition was determined by the sulphorhodamin B assay. The antiproliferative effects of the drug combinations were analysed using Berenbaum's hyperplane theorem to determine additive, synergistic and antagonistic effects. IFN beta was found to be 10,000 times more active in inhibiting cell growth of SK-MEL 28 cells than carboplatin on the basis of IC50 values (IFN beta: IC50 = 1.24 nM, carboplatin: IC50 = 18.2 microM). The addition of IFN beta at 0.5 nM reduced the IC50 value of carboplatin 18.0-fold; with IFN beta at 0.05 nM a dose reduction of 1.84 was measured. At the carboplatin: IFN beta molar concentration ratios of 2000:1 and 6000:1, interaction indices (I) of 0.66 and 0.83 were determined respectively, indicating synergistic interactions between the two drugs. At higher carboplatin: IFN beta molar ratios (20,000:1 and 60,000:1) an additive interaction was observed (I = 1.07 and 1.20). However, further in vitro studies with several melanoma cell lines are necessary to evaluate the potential effectiveness of the drug combination of carboplatin and IFN beta for eventual clinical utilisation.

Increase in calcitonin gene related peptide (CGRP) and decrease in mast cells in dihydroepiandrosterone (DHEA)-induced polycystic rat ovaries.

UNLABELLED: The polycystic ovary is reported to correspond with a high density in intraovarian nerve fibers and their sympathetic hyperresponsiveness. Peptidergic nerves may also be involved in this process. An interaction between nerve fibers and mast cells is assumed because of nerve growth-factor production by mast cells. Here we investigated CGRP-positive nerve fibers and mast cells in polycystic ovaries induced in immature rats with dihydroepiandrosterone (DHEA). The DHEA treated ovaries contained less corpora lutea than controls (mean +/- SEM: 4.3 +/- 0.6 versus 11.3 +/- 0.9, P > 0.001) and less intact antral follicles (4.7 +/- 0.7 versus 8.1 +/- 1.1; P < 0.05) according to the histometric approach. By immunolabelling more CGRP-positive nerve fibers were found in the DHEA treated ovaries than in controls (mean +/- SEM per one section: 23.2 +/- 5.8 fibers versus 10.3 +/- 0.9 and 171 +/- 44.7 varicosities versus 84 +/- 9.5). This was confirmed by dot blot analysis, showing a significant higher CGRP signal intensity per microgram homogenized ovaries of the DHEA treated group compared to the untreated (P < 0.05). Toluidine-blue-stained mast cells populated the medulla in both groups, yet had strikingly decreased in the DHEA treated ovaries (23.5 +/- 3.9 versus 89 +/- 5.6, P < 0.005). CONCLUSION: The increase in CGRP-positive nerve fibers and the decrease of toluidine-blue-stained mast cells points to an altered neuroimmune function in DHEA-induced polycystic rat ovaries.

High incidence of parvovirus B19 DNA in synovial tissue of patients with undifferentiated mono- and oligoarthritis.

A common problem in rheumatological practice is inflammatory joint disease that cannot be classified. The prognosis of such undifferentiated arthritides is uncertain. The synovial tissue of 41 consecutive patients with various forms of arthritis was tested for the presence of viral DNA in a diagnosis-unaware fashion, using the polymerase chain reaction (PCR). Of all tested viruses, cytomegalovirus and parvovirus B19 were positive (each in 10 patients, two double-positives), whereas herpes simplex virus was positive in two patients. Rubella virus RNA was detected in three specimens. When the positivity for viral material was analysed in terms of distribution among the various diagnostic groups, it became evident that five out of 10 parvovirus B 19-positive patients belonged to the undifferentiated arthritis group, whereas cytomegalovirus-positive patients were spread among all diagnostic groups. This indicates the possibility of a new diagnostic category of undifferentiated mono- and oligoarthritis, which can be identified by the presence of parvovirus B19 DNA in synovial tissue.

Rapid identification of Enterobacteriaceae using a novel 23S rRNA-targeted oligonucleotide probe.

The aim of this study was to rapidly identify bacteria of the family of Enterobacteriaceae using fluorescent in situ hybridization (FISH). A comparative sequence analysis was carried out and a 23S rRNA signature sequence for Enterobacteriaceae was identified. A 23S rRNA-targeted oligonucleotide probe (EBAC1790) was constructed and subsequently tested against 40 reference strains. Nearly all of the Enterobacteriaceae used in this study yielded positive results with EBAC1790, except for Edwardsiella tarda (ATCC 15947). None of the non-Enterobacteriaceae reference strains gave positive signals with the probe. The possibility of a rapid detection of Enterobacteriaceae in groundwater was demonstrated using colony hybridization.

Highly skewed T-cell receptor V-beta chain repertoire in the bone marrow is associated with response to immunosuppressive drug therapy in children with very severe aplastic anemia.

One of the major obstacles of immunosuppressive therapy (IST) in children with severe aplastic anemia (SAA) comes from the often months-long unpredictability of bone-marrow (BM) recovery. In this prospective study in children with newly diagnosed very severe AA (n=10), who were enrolled in the therapy study SAA-BFM 94, we found a dramatically reduced diversity of both CD4+ and CD8+ BM cells, as scored by comprehensive V-beta chain T-cell receptor (TCR) analysis. Strongly skewed TCR V-beta pattern was highly predictive for good or at least partial treatment response (n=6, CD8+ complexity scoring median 35.5, range 24-73). In contrast, IST in patients with rather moderate reduction of TCR V-beta diversity (n=4, CD8+ complexity scoring median 109.5, range 82-124) always failed (P=0.0095). If confirmed in a larger series of patients, TCR V-beta repertoire in BM may help to assign children with SAA up-front either to IST or to allogeneic stem-cell transplantation.

[Pain-related coping strategies in children and adolescents with chronic pain. Validation of a German version of the Paediatric Pain Coping Inventory (PPCI revised)]. / Schmerzbezogene Copingstrategien von Kindern und Jugendlichen mit chronischen Schmerzen. Uberprüfung einer deutschen Fassung der Paediatric Pain Coping Inventory (PPCI-revised).

Validated intruments for measuring coping in children and adolescents with chronic pain are rare in Germany. Using a sample of 180 out-patient children with chronic pain, a main component analysis was performed as well as cross-validations with out-patient and in-patient treated children. The scales of the PPCI-R showed significant relationships to pain characteristics and emotional stress. Different alterations were found in the PPCI-R scales in children with migraine and those with tension-type headache. The PPCI revised is therefore a validated instrument for measuring coping an can be implemented e.g. in treatment studies for children suffering from chronic pain.

Parents' perspective on symptoms, quality of life, characteristics of death and end-of-life decisions for children dying from cancer.

BACKGROUND: In the present study, we investigated the situation of children who had succumbed to their malignancy in Germany as perceived by their parents. Specifically, we were interested in bereaved parents' perspective on five essential areas: 1) symptoms and quality of life, 2) characteristics of the child's death, 3) anticipation of their child's death and care delivery, 4) end-of-life decisions and 5) impact of the child's death on the parents and perceived social support by the health care team. MATERIALS AND METHODS: We contacted all existing departments for paediatric oncology in the German federal state of Nordrhein Westfalen and asked them to contact all parents for participation in our study who had lost their child to cancer in 1999 and 2000. Upon agreement, we interviewed the parents utilising a validated semi-structured interview on distressing symptoms and quality of life of their children during the end-of-life care period. RESULTS: Six of the 19 departments agreed to participate. Parents of 48 children (31 boys, 17 girls) were interviewed. The main distressing symptoms were fatigue, pain, loss of appetite, and dyspnoea according to the parents. While parents perceived pain and constipation to have been treated successfully, loss of appetite and anxiety were not treated effectively. 75% of the children died due to a progression of their malignancy. Of these, 50% obtained cancer-directed therapy at the end of life, which was negatively rated by the parents in hindsight. 48% of the children died at home even though 88% of the parents chose 'at home' as the most appropriate locale of death in hindsight. Parents anticipated their child's death on average 9 weeks prior to the child's death. 41% of the parents provided palliative home care for their child and the majority (88%) rated the quality of care as good or very good. 64% discussed end-of-life decisions with the health care team, 36% did not have a discussion. Parents were clearly affected by their child's death. However, 15% of the parents were not contacted by the health care team following the child's death. CONCLUSIONS: The present study demonstrated that psychological symptoms (e.g. anxiety) are frequent symptoms in the end-of-life care period and cause severe suffering in the children. Questions in terms of benefits and costs of cancer-directed therapy in the end-of-life care period need to be addressed in future prospective studies. Parents' perspective on their child's death and related end-of-life decisions highlighted the importance of communication between parents and the health care team. Future studies need to investigate potential barriers in the communication between parents and the team to optimise end-of-life decisions and hence, reduce parents' long-term distress. In line with the previous, the present data demonstrated that there is still a lack of routine contact from the health care team following the child's death despite existing guidelines. Research is therefore needed into the implementation of guidelines for routine contact into clinical practice following a child's death.

Modification of ribonuclease T1 specificity by random mutagenesis of the substrate binding segment.

Attempts to modify the guanine specificity of ribonuclease T1 (RNase T1) by rationally designed amino acid substitutions failed so far. Therefore, we applied a semirational approach by randomizing the guanine binding site. A combinatorial library of approximately 1.6 million RNase T1 variants containing permutations of 6 amino acid positions within the recognition loop was screened on RNase indicator plates. The specificity profiles of 180 individual clones showing RNase activity revealed that variant K41S/N43W/N44H/Y45A/E46D (RNaseT1-8/3) exhibits an altered preference toward purine nucleotides. The ApC/GpC preference in the cleavage reaction of this variant was increased 4000-fold compared to wild-type. Synthesis experiments of dinucleoside monophosphates from cytidine and the corresponding 2'3'-cyclic diesters using the reverse reaction of the transesterification step showed a 7-fold higher ApC synthesis rate of RNase 8/3 than wild-type, whereas the GpC synthesis rates for both enzymes were comparable. This study shows that site-directed random mutagenesis is a powerful additional tool in protein design in order to achieve new enzymatic specificities.

Differential effect of purified spruce chitinases and beta-1,3-glucanases on the activity of elicitors from ectomycorrhizal fungi.

Two chitinases (EC 3.2.1.14) and two beta-1,3-glucanases (EC 3.2.1.39) were purified from the culture medium of spruce (Picea abines [L.] Karst.) cells to study their role in modifying elicitors, cell walls, growth, and hyphal morphology of ectomycorrhizal fungi. The 36-kD class I chitinase (isoelectric point [pl] 8.0) and the 28-kD chitinase (pl 8.7) decreased the activity of elicitor preparations from Hebeloma crustuliniforme (Bull. ex Fries.) Quél., Amanita muscaria (L.) Pers., and Suillus variegatus (Sw.: Fr.) O.K., as demonstrated by using the elicitor-induced extracellular alkalinization in spruce cells as a test system. In addition, chitinases released monomeric products from the walls of these ectomycorrhizal fungi. The beta-1,3-glucanases (35 kD, pl 3.7 and 3.9), in contrast, had little influence on the activity of the fungal elicitors and released only from walls of A. muscaria some polymeric products. Furthermore, chitinases alone and in combination with beta-1,3-glucanases had no effect on the growth and morphology of the hyphae. Thus, it is suggested that apoplastic chitinases in the root cortex destroy elicitors from the ectomycorrhizal fungi without damaging the fungus. By this mechanism the host plant could attenuate the elicitor signal and adjust its own defense reactions to a level allowing symbiotic interaction.

[A double-blind comparison of epidural buprenorphine and epidural morphine in postoperative pain (author's transl)]. / Peridurale Analgesie mit Buprenorpine und Morphin bei postoperativen Schmerzen.

Morphine (5 mg) and buprenorphine (0.15 mg) given by the epidural route were compared in 50 patients recovering from abdominal surgery. Pain relief score, sedation score and clinical measures were evaluated in a double-blind study. Both substances produced thorough analgesia with short latency (2-6 min) of long duration (8-9 h). Side effects were encountered in some morphine cases only, but never therapy had to be discontinued. Total lack of side effects with buprenorphine favours its application in epidural pain relief.

Chronic occupational exposure to organic solvents. XV. Glycol ether exposure during the manufacture of brakehoses.

Twenty-two persons (20 men and 2 women) were examined for their external and internal exposure to the glycol ether 1-methoxypropan-2-ol (PGME) during the production, leak testing and mounting of brakehoses. For the measurement of external exposure, personal air monitoring was the method of choice. Average concentrations of PGME of 82.2 mg/m3 (22.3 ppm), 68.6 mg/m3 (18.6 ppm) and 11.3 mg/m3 (3.1 ppm) were found in the air of the brakehose production, leak test and mounting areas, respectively. For the estimation of internal exposure to PGME, this glycol ether was measured in both urine and blood. The biological samples were taken post-shift. The highest internal exposure levels were found in the brakehose production section and in the leak test area. The average post-shift concentrations for PGME in workers in the brakehose production section were 4.6 mg/l in urine and 13.5 mg/l in blood; the corresponding figures for workers in the leak test area were 4.2 mg/l in urine and 11.0 mg/l in blood. In blood and urine samples of workers engaged in the mounting area, PGME levels were below the detection limits. The elimination kinetics of PGME were also studied in three highly exposed persons, and mean excretion half-lives of PGME of approximately 4.4 h were found. On the basis of our results we made a rough calculation of a future biological tolerance value: we would except that concentrations of 38-109 mg per litre of blood and 10-31 mg per litre of urine would correspond to the German MAK value for PGME (375 mg/m3).