Clozapine-associated elevation of plasma cholinesterase

OBJECTIVE

The goal of this study was to identify adverse effects of the atypical neuroleptic clozapine on liver function and lipid metabolism.

METHODS

Data which included serum levels of clozapine and its hepatic metabolite N-desmethyl clozapine were collected from medical records of patients treated with clozapine and controls.

RESULTS

We identified a clozapine-associated marked elevation of plasma cholinesterase (ChE) with unchanged levels of AST, ALT or g-GT. ChE was correlated to the serum level of clozapine and even closer to N-desmethyl clozapine. For the total patient group we observed significant correlations of ChE with the body-mass index and body weight. However, clozapine-treated patients and controls did not differ with regard to body-mass index, triglycerides, and cholesterol.

CONCLUSION

We report for the first time a clozapine-associated and dose-dependent elevation of plasma ChE, which may be related to clozapine-associated effects on hepatic lipid metabolism or ChE enzyme induction.

Intraoperative radiofrequency maze ablation for atrial fibrillation: the Berlin modification

BACKGROUND

The Cox-maze procedure combined with an operation for organic heart disease is highly successful in the elimination of chronic atrial fibrillation. However, it prolongs significantly the aortic cross-clamp and operating time. In this study, a simplified left atrial maze procedure, which is a short procedure performed using a surgical radiofrequency ablation probe, is added to elective open heart procedures in patients with atrial fibrillation.

METHODS

Forty-eight adults with atrial fibrillation (duration, 6 months to 36 years) underwent elective open heart operations (isolated valve procedures or coronary artery bypass grafting, n = 27 patients; combined procedures, n = 21 patients) combined with intraoperative radiofrequency ablation of the left atrium. The postoperative follow-up period ranged from 1 to 11 months (mean, 4 months). Possible predictors for persistent postoperative atrial fibrillation were determined among 40 variables by univariate and multivariate analyses.

RESULTS

Intraoperative radiofrequency ablation prolonged the aortic cross-clamp time for 6 to 14 minutes (mean, 11 minutes). Freedom from atrial fibrillation was 100% intraoperatively, 25% at 1 week after operation (12 of 48 patients), 59% at 1 month postoperatively (16 of 27 patients), 64% at 3 months postoperatively (16 of 25 patients), and 92% at 6 months postoperatively (12 of 13 patients). The only predictor of postoperative atrial fibrillation was the presence of coronary artery disease (odds ratio, 7.5; 80% confidence interval, 2.24-25.13).

CONCLUSIONS

Intraoperative radiofrequency ablation of the left atrium combined with an operation for organic heart disease effectively eliminates atrial fibrillation without significant prolongation of the aortic cross-clamp and operative time. The presence of coronary artery disease decreases the success rate during the first 6 postoperative months.

Self-deleting suicide vectors (SDSV): selective killing of p53-deficient cancer cells

A self-deleting retrovirus vector carrying a herpes simplex virus (HSV)-thymidine kinase suicide gene has been developed to selectively kill cancer cells expressing a dysfunctional p53 tumor suppressor protein. When cells containing functional p53 are infected with the virus, the integrated provirus and the HSV-thymidine kinase gene are deleted from the genome by site-specific recombination (Cre/loxP). In contrast, cells without p53 or cells expressing a DNA-binding mutant of p53 retain the provirus and become susceptible to killing by ganciclovir. This strategy provides a new concept for the selective killing of cancer cells that can be adapted to any other dysfunctional transcription factor expressed by different tumors.

Integrin and talin in the jellyfish Podocoryne carnea

We have isolated an integrin-beta and -alpha subunit from Podocoryne carnea (Cnidaria, Hydrozoa) and studied their expression in the life-cycle and during cell migration, in vitro transdifferentiation and regeneration. Comparison of the integrin expression pattern with a Podocoryne talin homologue by RT-PCR demonstrates that all three genes are maternal messages and continuously expressed in the life-cycle, in medusa development and in all medusae tissues. In situ hybridisation experiments confirm co-expression of both integrin subunits in the different life-stages. Integrin expression was furthermore studied in isolated striated muscle induced to transdifferentiate to new cell types, or grafted on ECM where the muscle adheres and migrates. Integrin expression was maintained continuously throughout both processes. These results suggest that in Podocoryne carnea processes such as cell migration and differentiation are not controlled by up- or downregulation of alternative integrin subunits, but by a single integrin heterodimer which activates different downstream signalling cascades.

The value of desoxypyridinoline in the diagnostics of loosened arthroplasty

According to several reports in the last few years, desoxypyridinoline (Dpd) in urine increases significantly in cases of loosened arthroplasty. Therefore, this marker was suggested as useful in the diagnostics of implant loosening. In this study, the level of Dpd was determined in 69 patients with arthroplasty of the hip or the knee joint. Thirty-four of these patients received revision surgery following implant loosening. In 35 of these 69 patients, there were no clinical or radiological signs of loosening (control group). The mean age of the patients with loosened implants (22 women, 13 men) was 67.9 years and of the control group (22 women, 12 men) 66.9 years. In the group with arthroplastic loosening, as well as in the control group, 14 patients had increased levels of Dpd. There were 20 patients in the group with loosened arthroplasty and 19 patients in the control group that had normal levels of Dpd. The female patients had a mean Dpd level of 8.6 nmol/mmol creatinine (4.3-24 nmol/mmol creatinine) in the urine in cases of loosening and 10.1 nmol/mmol creatinine (2-33 nmol/mmol creatinine) in the control group. The male patients had a mean Dpd level of 7.8 nmol/mmol creatinine (3.2-19.2 nmol/mmol creatinine) in the urine in cases of loosening and 5.8 nmol/mmol creatinine (0.3-11.7 nmol/mmol creatinine) in the control group. In conclusion there was no significant increase in Dpd in patients with implant loosening compared with the control group. Furthermore, older patients often suffer from diseases causing increased bone resorption that may falsify the test results. We cannot confirm that Dpd is helpful in the diagnostics and screening of implant loosening.

Disseminated cytokeratin positive tumor cells in the bone marrow of patients with prostate cancer: detection and prognostic value

PURPOSE

Previous investigations have shown that cytokeratin 18 positive bone marrow cells in localized and lymphatically spread prostate cancer correlates with neither established prognostic factors nor with the biochemical and clinical course after radical prostatectomy. Since the well-known down-regulation of cytokeratin 18 in tumor cells may lead to false-negative results, we asked whether staining with a pan-cytokeratin antibody recognizing a common epitope of cytokeratins 8, 18 and 19 would result in different data.

MATERIALS AND METHODS

Preoperative bone marrow aspirates of 82 patients with localized (N0) and lymphatically spread (N1) prostate cancer were examined using the monoclonal antibody cytokeratin 2 and the pan-cytokeratin antibody A 45-B/B3, called A 45.

RESULTS

In contrast to findings with the cytokeratin 18 antibody, those with the pan-cytokeratin antibody correlated with the biochemical course. At a median followup of 1,477 days (4 years) patients with pan-cytokeratin positive cells in the preoperative bone marrow aspirate had biochemical progression significantly earlier than those with pan-cytokeratin negative results (mean time to prostate specific antigen relapse 886 versus 1,409 days, p < or =0.004). Compared with other parameters, such as prostate specific antigen, pathological stage and Gleason score, preoperative pan-cytokeratin findings proved to be an independent prognostic factor.

CONCLUSIONS

Cytokeratin positive cells in the bone marrow also have prognostic relevance in prostate cancer. The comprehensive analysis of these cells, studies of the individual course of these findings and sufficiently long followup allow us to discuss whether and under what conditions metastasis may develop from 1 or several cytokeratin positive cells.

Disseminated cytokeratin positive tumor cells in the bone marrow of patients with prostate cancer: detection and prognostic value

PURPOSE

Previous investigations have shown that cytokeratin 18 positive bone marrow cells in localized and lymphatically spread prostate cancer correlates with neither established prognostic factors nor with the biochemical and clinical course after radical prostatectomy. Since the well-known down-regulation of cytokeratin 18 in tumor cells may lead to false-negative results, we asked whether staining with a pan-cytokeratin antibody recognizing a common epitope of cytokeratins 8, 18 and 19 would result in different data.

MATERIALS AND METHODS

Preoperative bone marrow aspirates of 82 patients with localized (N0) and lymphatically spread (N1) prostate cancer were examined using the monoclonal antibody cytokeratin 2 and the pan-cytokeratin antibody A 45-B/B3, called A 45.

RESULTS

In contrast to findings with the cytokeratin 18 antibody, those with the pan-cytokeratin antibody correlated with the biochemical course. At a median followup of 1,477 days (4 years) patients with pan-cytokeratin positive cells in the preoperative bone marrow aspirate had biochemical progression significantly earlier than those with pan-cytokeratin negative results (mean time to prostate specific antigen relapse 886 versus 1,409 days, p < or =0.004). Compared with other parameters, such as prostate specific antigen, pathological stage and Gleason score, preoperative pan-cytokeratin findings proved to be an independent prognostic factor.

CONCLUSIONS

Cytokeratin positive cells in the bone marrow also have prognostic relevance in prostate cancer. The comprehensive analysis of these cells, studies of the individual course of these findings and sufficiently long followup allow us to discuss whether and under what conditions metastasis may develop from 1 or several cytokeratin positive cells.

Specific detection of Bradyrhizobium and Rhizobium strains colonizing rice (Oryza sativa) roots by 16S-23S ribosomal DNA intergenic spacer-targeted PCR

In addition to forming symbiotic nodules on legumes, rhizobial strains are members of soil or rhizosphere communities or occur as endophytes, e.g., in rice. Two rhizobial strains which have been isolated from root nodules of the aquatic legumes Aeschynomene fluminensis (IRBG271) and Sesbania aculeata (IRBG74) were previously found to promote rice growth. In addition to analyzing their phylogenetic positions, we assessed the suitability of the 16S-23S ribosomal DNA (rDNA) intergenic spacer (IGS) sequences for the differentiation of closely related rhizobial taxa and for the development of PCR protocols allowing the specific detection of strains in the environment. 16S rDNA sequence analysis (sequence identity, 99%) and phylogenetic analysis of IGS sequences showed that strain IRBG271 was related to but distinct from Bradyrhizobium elkanii. Rhizobium sp. (Sesbania) strain IRBG74 was located in the Rhizobium-Agrobacterium cluster as a novel lineage according to phylogenetic 16S rDNA analysis (96.8 to 98.9% sequence identity with Agrobacterium tumefaciens; emended name, Rhizobium radiobacter). Strain IRBG74 harbored four copies of rRNA operons whose IGS sequences varied only slightly (2 to 9 nucleotides). The IGS sequence analyses allowed intraspecies differentiation, especially in the genus Bradyrhizobium, as illustrated here for strains of Bradyrhizobium japonicum, B. elkanii, Bradyrhizobium liaoningense, and Bradyrhizobium sp. (Chamaecytisus) strain BTA-1. It also clearly differentiated fast-growing rhizobial species and strains, albeit with lower statistical significance. Moreover, the high sequence variability allowed the development of highly specific IGS-targeted nested-PCR assays. Strains IRBG74 and IRBG271 were specifically detected in complex DNA mixtures of numerous related bacteria and in the DNA of roots of gnotobiotically cultured or even of soil-grown rice plants after inoculation. Thus, IGS sequence analysis is an attractive technique for both microbial ecology and systematics.

[Causal beliefs of schizophrenic patients]

RESEARCH QUESTION

Aim of the study is to investigate whether the preference of schizophrenic patients for psychosocial causal explanations found in a previous study carried out in Hamburg can be observed elsewhere. Further aim of the study was to find out how stable patients' causal attributions are over time. Finally, we were interested to know to what degree patients' beliefs reflect those held by the general public.

METHOD

Using an inventory comprising 15 items, we inquired about 105 schizophrenic patient's aetiological ideas at the time of discharge from hospital from inpatient or daycare treatment at 4 psychiatric hospitals in Germany. Follow-ups were carried out 3 months and 6 months later.

RESULTS

Psychosocial factors, especially psychosocial stress, were most frequently held responsible for the onset of the illness. The possibility that biological factors might play a role in the causation of schizophrenia was considered more rarely by the patients. There were practically no regional variations as concerns aetiological beliefs. The tendency to endorse psychosocial stress factors was more pronounced among patients as compared with the general public. In total the causal beliefs proved to be quite stable over a time period of 6 months.

DISCUSSION

Patients' causal beliefs are compared with findings of psychiatric research, and possible ways to bridge the gap between the two are discussed.

Influence of the bovine seminal plasma protein PDC-109 on the physical state of membranes

PDC-109 is the main component of bovine seminal plasma and has been suggested to play an important role in the genesis of bovine sperm cells. Here, the effect of binding of PDC-109 to membranes on the structure and physical properties of the lipid phase was investigated. For that, ESR measurements were undertaken on model membranes (lipid vesicles) and on biological membranes (epididymal spermatozoa) by employing various spin-labeled phospholipids. We found that PDC-109 alters the membrane structure of lipid vesicles as well as of bovine epididymal spermatozoa in that the mobility of spin-labeled phospholipids was reduced in the presence of the protein. This immobilizing effect of the protein was not restricted to analogues of phosphatidylcholine but was also detected with spin-labeled phosphatidylethanolamine. However, the extent of immobilization was lower for phosphatidylethanolamine compared with phosphatidylcholine, supporting the lipid headgroup specificity of the protein. Besides phospholipid headgroups, the physical state of membrane lipids is also important for the interaction of PDC-109 with membranes, in that, e.g., the immobilizing effect of the protein on labeled lipids was larger in membranes above the phase transition temperature compared with the effect below this temperature. The results are of relevance for understanding the physiological role of PDC-109 in the genesis of sperm cells.

Halogenodisilanes: precursors for new disilane derivatives

Starting from hexachloro- or hexabromodisilane a wide variety of 1,2-disubstituted tetrachlorodisilanes (RSiCl2SiCl2R) [R = Cp (2a), 4-iPrC6H4(SiMe3)N (2b), 2,6-iPr2C6H3(SiMe3)N (2c), (Me3Si)2CH (2d) (Me3Si)3C (2e), (Me3Si)3Si (2f)], tetrabromodisilanes (RSiBr2SiBr2R) [R = Cp (3a), 4-iPrC6H4(SiMe3)N (3b), (Me3Si)3Si (3f)] and the monosubstituted pentahalogenodisilanes CpSiX2SiX3 [X = Cl (4), Br (5)] were prepared. The tetrachlorodisilanes 2a-e are converted to various functionalized disilanes. Ammonolysis of 2a-e leads to the tetraaminodisilanes [RSi(NH2)2Si(NH2)2R] 6a-e. A reduction of 2d with LiAlH4 resulted in the formation of the disilane RSiH2SiH2R [R = (Me3Si)2CH] 7 and the metathesis with Me3SnF yielded the tetrafluorodisilane RSiF2SiF2R [R = (Me3Si)2CH] 8. Treatment of 6d with reagents containing H acidic protons (HX) [X = Br, I and OH] leads under elimination of NH3 to the tetrabromo- R2SiBr2SiBr2R (3d) tetraiodo- RSiI2SiI2R (9) and the tetrahydroxodisilane RSi(OH)2Si(OH)2R (10) [R = (Me3Si)2CH]. Single-crystal X-ray structural analysis of 2d, 6a, 6d, and 9 are reported.

Pancreatic adenocarcinoma cell lines show variable susceptibility to TRAIL-mediated cell death

BACKGROUND AND AIMS

Programmed cell death via the Fas receptor/Fas Ligand and DR4, DR5/TRAIL plays a major role in tumor escape and elimination mechanisms. It also promises to be an effective therapy alternative for aggressive tumors, as has been recently shown for colon, breast, and lung cancer cells. We attempted to clarify the role of these molecules in aggressivity of pancreatic carcinomas and to identify possible pathways as targets for therapy.

METHODS

Five pancreatic cell lines were investigated for the expression of FasL/Fas, DcR3, DR4, DR5/TRAIL, DcR1, DcR2, and other death pathways related molecules such as Bax, bcl-xL, bcl-2, FADD, and caspase-3 by flow cytometry, immunoblotting, and RT/PCR, both semiquantitative and real time (TaqMan). The susceptibility of these cell lines to apoptosis mediated by recombinant TRAIL was investigated. The effect of therapeutic agents (gemcitabine) on their susceptibility to TRAIL induced apoptosis was studied as well.

RESULTS

Pancreatic adenocarcinomas expressed high levels of apoptosis-inducing receptors and ligands. They showed differential susceptibility to cell death induced by TRAIL, despite expressing intact receptors and signaling machineries. Treatment with commonly used therapeutic agents did not augment their susceptibility to apoptosis. This could be explained by the fact that they expressed differentially high levels of decoy receptors, as well as molecules known as inhibitors of apoptosis.

CONCLUSIONS

The data suggest that pancreatic carcinoma cells have developed different mechanisms to evade the immune system. One is the expression of nonfunctional receptors, decoy receptors, and molecules that block cell death, such as bcl2 and bcl-xL. The second is the expression of apoptosis-inducing ligands, such as TRAIL, that could induce cell death of immune cells. The success in treating malignant tumors by recombinant TRAIL might apply to some but not all pancreatic tumors because of their differential resistance to TRAIL-induced cell death.

[Number of hospitalizations according to German "PsychKG" legislation has doubled in 10 years]

AIM

to examine the frequency of involuntary hospitalisation according to PsychKG (german law concerning psychiatric practice) in a comprehensive region with good overall medical/psychiatric services, over the course of a decade.

METHOD

All cases of compulsory admission into Psychiatric Clinics within the greater Göttingen area (Central Germany) were evaluated every two years between 1988 and 1998.

RESULTS

The number of involuntarily hospitalised patients doubled within the ten years of evaluation although the density of population remained stable and the already good quality out-patient treatment experienced further improvement. However, the total number of in-patients also doubled during this time, so that the proportion between compulsory admission and voluntary hospitalisation remained the same.

CONCLUSION

Similar to other regions, the increase in compulsory admissions is considerable. The development towards shorter treatments and an increasing frequency of re-hospitalisation seem to have no significant influence on the courses of disease or on future pathological crises of the patients in question. It is possible that the expected lack of a decreasing rate of compulsory admission is partly caused by behaviour on the part of the physician.

41Ca ultratrace determination with isotopic selectivity > 10(12) by diode-laser-based RIMS

41Ca ultratrace determination by diode-laser-based resonance ionization mass spectrometry with extremely high isotopic selectivity is presented. Application to environmental dosimetry of nuclear reactor components, to cosmochemical investigations of production cross sections, and biomedical isotope-tracer studies of human calcium kinetics are discussed. Future investigations are possible use in 41Ca-radiodating. Depending on the application, 41Ca isotopic abundances in the range of 10(-9) to 10(-15) relative to the dominant stable isotope 40Ca must be determined. Either double- or triple-resonance optical excitation with narrow-band extended cavity diode lasers and subsequent non-resonant photoionization of calcium in a collimated atomic beam were used. The resulting photoions are detected with a quadrupole mass spectrometer optimized for background reduction and neighboring mass suppression. Applying the full triple-resonance scheme provides a selectivity of approximately 5 x 10(12) in the suppression of neighboring isotopes and > 10(8) for isobars, together with an overall detection efficiency of approximately 5 x 10(-5). Measurements on a variety of sample types are discussed; the accuracy and reproducibility of the resulting 41Ca/40Ca isotope ratios was better than 5%.

Magnetic anisotropy of a cyclic octanuclear Fe(III) cluster and magneto-structural correlations in molecular ferric wheels

The magnetic anisotropy of the cyclic octanuclear Fe(III) cluster [Cs subsetFe(8)[N(CH(2)CH(2)O)(3)](8)]Cl was investigated. Based on a spin Hamiltonian formalism and the consequent use of all symmetries, the magnetic anisotropy could be calculated exactly to first order, i.e., in the strong exchange limit. Experimentally, the magnetic anisotropy was investigated by magnetic susceptibility and high-field torque magnetometry of single crystals. The field and angle dependence of the torque at 1.7 K could be accurately reproduced by the calculations with one single parameter set, providing accurate results for the coupling constant and single-ion zero-field-splitting. These magnetic parameters are compared to those of several related hexanuclear ferric wheels and are discussed with respect to magneto-structural correlations for both coupling constant and single-ion anisotropy.

Immortalized bovine pancreatic duct cells become tumorigenic after transfection with mutant k-ras

Mutation of the K-ras gene is thought to be an early and important event in pancreatic carcinogenesis. In order to study the role of this molecular alteration in the transition from the normal to the neoplastic pancreatic cell, bovine pancreatic duct cells were first immortalized by SV40 large T antigen (Ag) complementary (c)DNA transfection and then transfected with a mutated K-ras gene. As did primary duct cells, the immortalized duct cells (more than 100 passages) expressed cytokeratins, carbonic anhydrase type-II, cystic fibrosis transmembrane conductance regulator (CFTR), and multidrug resistance (mdr). They grew as a single layer after transplantation under plastic domes and formed three-dimensional structures resembling ducts when grown on Matrigel. Cell growth was stimulated by insulin, epidermal growth factor (EGF), transforming growth factor (TGF)-alpha, but cells did not respond to gastrin and CCK-8. They did not form colonies in soft agar nor did they form tumors in nude mice. Immortalized cells transfected with mutated K-ras acquired the ability to form tumors after orthotopic injection into the nude mouse pancreas. It is concluded that SV 40 immortalized bovine pancreatic

p53 and K-ras mutations in pancreatic juice samples from patients with chronic pancreatitis

BACKGROUND

Mutations in p53 and ras genes are frequent in pancreatic carcinoma. Several ras mutations are consistently detected in the pancreatic juice from patients with chronic pancreatitis. The p53 gene mutations have been detected occasionally in chronic pancreatitis tissue. It was the aim of this study to evaluate the presence and clinical significance of p53 and ras mutations in clinical pancreatic juice samples from patients with chronic pancreatitis.

METHODS

Pancreatic juice was obtained from 66 patients with chronic pancreatitis and no evidence of pancreatic carcinoma (51 men, 15 women; age 17-86 years [mean 49.6 +/- 12.9]). Patients were followed prospectively for 26 +/- 3 (4-54) months. Detection of p53 gene mutations was by temperature gradient gel electrophoresis (TGGE) and single strand conformation polymorphism (SSCP) for exons 5-8. Analysis of ras mutations was performed by SSCP/polymerase chain reaction, restriction fragment length polymorphism/polymerase chain reaction. All mutations were confirmed by sequencing.

RESULTS

Five of 66 (7.5%) pancreatic juice samples contained p53 mutations, and ras mutations were detected in 6 cases (9%). Cytology was negative in all cases. No pancreatic carcinoma developed during follow-up and neither cancer cells nor preneoplastic lesions could be detected histologically in resected specimens. Although no correlation between p53 mutations and duration of pancreatitis or drinking habits was found, K-ras mutations correlated with both heavy smoking and severity of the disease.

CONCLUSION

p53 and ras mutations can be detected in a minority of pancreatic juice samples from patients with chronic pancreatitis in the absence of malignancy.

Percutaneous core-needle biopsy of enlarged lymph nodes in the diagnosis and subclassification of malignant lymphomas

The objective of this study was to evaluate the sensitivity and specificity of percutaneous core-needle biopsy of enlarged lymph nodes in the diagnosis and subclassification of malignant lymphomas. In a 1-year period 158 image-guided percutaneous core-needle biopsies of enlarged lymph nodes were performed on 149 consecutive patients using a Tru-cut needle fired by a biopsy gun. In 135 cases the biopsy findings could be confirmed by histologic examination of additional tissue samples (n = 59) or by correlation with the patient's clinical and radiologic course (n = 76). The final diagnoses were malignant lymphoma in 65 cases, leukemic nodal infiltration in 2, nodal metastases from a solid tumor in 37 and benign changes or no evidence of malignancy in 31 cases. The core-needle biopsies correctly diagnosed 58 of 65 malignant lymphomas, corresponding to a sensitivity of 89% and a specificity of 97%. Fifty-five of the 58 (95%) correctly diagnosed malignant lymphomas could be subclassified on the basis of the core-needle biopsy. Image-guided core-needle biopsy of enlarged lymph nodes with a Tru-cut needle is a useful method for the diagnosis and subclassification of malignant lymphomas.

Microencapsulated cell-mediated treatment of inoperable pancreatic carcinoma

Pancreatic cancer can seldom be resected, and chemotherapy has only a limited effect on survival or tumour load. We did a phase I/II trial in 14 patients with pancreatic cancer to assess the safety of local activation of low-dose ifosfamide. We encapsulated genetically modified allogeneic cells, which expressed a cytochrome P450 enzyme, in cellulose sulphate and delivered them by supraselective angiography to the tumour vasculature. These cells locally activated systemically administered ifosfamide. The tumours of four patients regressed after treatment, and those of the other ten individuals who completed the study remained stable. Median survival was doubled in the treatment group by comparison with historic controls, and 1-year survival rate was three times better. Further studies of this cell-therapy-based treatment combined with chemotherapy for inoperable pancreatic cancer are warranted.

[Etiology of schizophrenia from the viewpoint of the patient]

OBJECTIVE

According to a quantitative study on causal beliefs patients with functional psychoses favour psychosocial over biological explanations. They also tend to endorse a multicausal concept. The aim of this study is to try to replicate these findings using semiqualitative methods.

METHODS

Problem-centered interviews were conducted with 78 schizophrenic patients consecutively discharged from inpatient or dayhospital treatment.

RESULTS

As in the previous study, patients provided more frequently psychosocial explanations. Biological causes were relatively rarely mentioned--mostly in response to suggestions of the interviewer. In addition, they were rather brief and not very elaborated. By contrast to the previous study, hardly any indications for a multicausal concept could be observed.

DISCUSSION

Patients' beliefs are contrasted with the results of psychiatric research on the causes of schizophrenia.

Patients' and relatives' assessment of clozapine treatment

BACKGROUND

Subjective evaluations by schizophrenic patients and their relatives of clozapine treatment were assessed as part of an exploratory study.

METHODS

A problem-centred interview was carried out with 80 patients at discharge from in-patient or day-hospital treatment. Views of 46 relatives on the treatment were also assessed.

RESULTS

In addition to expected effects (improvement of or stabilisation of one's state of mental health, antipsychotic effects), patients surprisingly often highlighted the calming and relaxing effect of clozapine as well as improved sleep as particularly positive. While more than half of the respondents expected a worsening of their condition if they stopped taking medication, only every fifth patient feared a relapse. Among the negative effects, fatigue and sedation were cited by far the most often. The absence of extrapyramidal side effects was clearly noted as an advantage of clozapine. Only 10% of those questioned were aware of the risks for the haemotopoetic system associated with the drug. Differences were found between patients' and relatives' assessments particularly with regard to the negative effects.

CONCLUSIONS

Patients and relatives frequently hold specific and distinct views on clozapine treatment. These views should be considered when patients and relatives are informed and when compliance is addressed.

[Etiology of schizophrenia from the viewpoint of family]

OBJECTIVE

In a former quantitative study on relatives' beliefs about the causes of functional psychoses a preference for psychosocial explanations was found. There were also indications of an inclination towards a multicausal concept. The aim of this study is to try to replicate these findings using semi-qualitative methods. In addition, we are interested in knowing to what extent the causal beliefs of relatives are similar to those of the patients.

METHOD

Problem-centered interviews were conducted with 31 relatives of schizophrenic patients. A computer-assisted qualitative content analysis was carried out with the transcripts of the interviews.

RESULTS

As in the previous study, relatives showed a strong propendency to endorse psychosocial explanations. However, among only one third a multicausal concept could be observed. The causal beliefs of relatives and patients were quite similar.

DISCUSSION

The findings are discussed with reference to the concept of subjective illness theory and the concept of social representations.

Vesicular and nonvesicular transport of phosphatidylcholine in polarized HepG2 cells

We have investigated the transport and canalicular enrichment of fluorescent phosphatidylcholine (PC) in HepG2 cells using the fluorescent analogs of PC C6-NBD-PC and beta-BODIPY-PC. Fluorescent PC was efficiently transported to the biliary canaliculus (BC) and became enriched on the lumenal side of the canalicular membrane as shown for C6-NBD-PC. Some fluorescent PC was transported in vesicles to a subapical compartment (SAC) or apical recycling compartment (ARC) in polarized HepG2 cells as shown by colocalization with fluorescent sphingomyelin (C6-NBD-SM) and fluorescent transferrin, respectively. Extensive trafficking of vesicles containing fluorescent PC between the basolateral domain, the SAC/ARC and the BC as well as endocytosis of PC analogs from the canalicular membrane were found. Evidence for nonvesicular transport included enrichment of the PC-analog beta-BODIPY-PC in the BC (t1/2 = 3.54 min) prior to its accumulation in the SAC/ARC (t1/2 = 18.5 min) at 37 degrees C. Transport of fluorescent PC to the canalicular membrane also continued after disruption of the actin or microtubule cytoskeleton and at 2 degrees C. These results indicate that: (i) a nonvesicular transport pathway significantly contributes to the canalicular enrichment of PC in hepatocytic cells, and (ii) vesicular transport of fluorescent PC occurs from both membrane domains via the SAC/ARC.

A shot in the dark: the silent quest of a free-flying phonotactic fly

To reproduce, females of the parasitoid fly Ormia ochracea detect and localise a calling male cricket upon which they deposit their endoparasitic larvae. Calling male crickets are therefore subject to both sexual and natural selection by simultaneously attracting mates and phonotactic parasitoids. The possible strategy of song interruption employed by the cricket host to reduce his attractiveness to acoustic parasitoids was tested in the laboratory by examining the fly's phonotactic quest in response to synthetic cricket songs. Phonotactic flight trajectories were recorded in three dimensions with a stereo infrared video tracking system while the sound stimulus was controlled on-line as a function of the fly's position in space. Within a single flight, three distinct phases could be observed: a take-off phase, a cruising phase, during which course and altitude were rather constant, and a landing phase characterised by a spiralling descent towards the sound source. The flies showed remarkable phonotactic accuracy in darkness; they landed at a mean distance of 8.2 cm from the centre of the loudspeaker after a flight distance of approximately 4 m. The present data illustrate the fly's surprising ability to gauge the direction and distance of a sound source in three dimensions and, subsequently, to find it in darkness and silence.

Low frequency of p53 and ras mutations in bile of patients with hepato-biliary disease: a prospective study in more than 100 patients

The diagnosis of biliary disease, namely malignant disorders, is frequently hampered by the inconclusive cytology. We investigated prospectively the frequency of molecular changes in p53 and ras compared with cytology in patients with primary or secondary hepato-biliary disease. We investigated 118 consecutive patients, aged 24-89 with the following clinical diagnoses: choledocho/cholecystolithiasis (28), cholangiocellular carcinoma (21), gall bladder tumor (8), liver metastasis (3), autoimmune disease (8), chronic pancreatitis (16), pancreatic carcinoma (11), papillary disease (4), hepatic cirrhosis (6), cholangitis (2), anomalies (2), and normal (9). Bile was aspirated during routine endoscopic retrograde cholangio pancreatography (ERCP) or percutaneous transhepatic cholangiography (PTC). DNA was prepared freshly from a native aliquot. p53 mutations were detected by polymerase chain reaction (PCR) for exons 5 through 8 followed by TGGE. PCR for ras mutations was performed as RFLP-PCR with sequencing. In four cases, mutations in p53 could be found in exons 6 and 7. Twenty-two samples showed ras mutations; ras mutations were found in choledocholithiasis (4/28), bile duct (5/21), gall bladder (3/8) and pancreatic (1/11) carcinoma, liver metastasis (3/3), ulcerative colitis (2/3), PSC (1/2), and chronic pancreatitis (1/16). Cytology was clearly positive in seven cases, suspicious in three other, inconclusive in six, and negative in the rest. The molecular analysis resulted in a sensitivity of 33% and specificity of 87%, respectively, for the diagnosis of a malignant condition. PCR for p53 and ras mutations may aid the diagnosis of primary and secondary (metastatic) hepatobiliary disease if a malignant condition of the bile ducts and the liver is suspected and cytology is inconclusive or negative. However, the incidence of p53 and ras mutations in bile seems less frequent than in other malignant conditions of the gastrointestinal tract and the pancreas and lower than in tissue, leaving a poor sensitivity and specificity. Nevertheless, the presence of a p53 and/or ras mutation per se supports a clinical suspicion of malignancy, even when the conventional cytology is negative or inconclusive.

Three cases with different presentation of fentanyl-induced muscle rigidity--a rare problem in intensive care of neonates

We report about two newborns with sudden onset of inability of mechanical ventilation due to transient chest wall rigidity after fentanyl i.v. bolus of 2 and 4 microg/kg, respectively, resulting in severe hypoxemia and secondary bradycardia. A third case developed a rigidity of the tongue after fentanyl bolus, which created some unusual difficulties in bypassing the tongue for insertion an endotracheal tube. Because of common usage of this agent for analgesia we direct attention to the possibility of fentanyl-induced muscle rigidity. We underline the necessity of a slow bolus injection to prevent this dangerous adverse effect and we recommend the administration of naloxone and/or muscle relaxants as therapy in conjunction with mechanical ventilation.

Dynamics of membrane penetration of the fluorescent 7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD) group attached to an acyl chain of phosphatidylcholine

Location and dynamic reorientation of the fluorophore 7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD) covalently attached to a short (C6) or a long (C12) sn2 acyl chain of a phosphatidylcholine molecule was investigated by fluorescence and solid-state NMR spectroscopy. 2H NMR lipid chain order parameters indicate a perturbation of the phospholipid packing density in the presence of NBD. Specifically, a decrease of molecular order was found for acyl chain segments of the lower, more hydrophobic region. Molecular collision probabilities determined by 1H magic angle spinning nuclear Overhauser enhancement spectroscopy indicate a highly dynamic reorientation of the probe in the membrane due to thermal fluctuations. A broad distribution of the fluorophore in the lipid bilayer is observed with a preferential location in the upper acyl chain/glycerol region. The distribution of the NBD group in the membrane is quite similar for both the long- and the short-chain analog. However, a slight preference of the NBD group for the lipid-water interface is found for C12-NBD-PC in comparison with C6-NBD-PC. Indeed, as shown by dithionite fluorescence assay, the long-chain analog reacts more favorably with dithionite, indicating a better accessibility of the probe by dithionite present in the aqueous phase. Forces determining the location of the fluorophore in the lipid water interface are discussed.

Light-induced reorganization of phospholipids in rod disc membranes

The transbilayer redistribution of spin-labeled phospholipid analogues (SL-PL) with choline, serine, and ethanolamine head groups (PC, PS, and PE, respectively) was studied on intact disc vesicles of bovine rod outer segment membranes in the dark and after illumination. Redistribution was measured by the extraction of spin-labeled lipid analogues from the outer leaflet of membrane using the bovine serum albumin back-exchange assay. In the dark, PS was distributed asymmetrically, favoring the outer leaflet, whereas PC and PE showed small if any asymmetry. Green illumination for 1 min caused lipid head group-specific reorganization of SL-PL. Extraction of SL-PS by bovine serum albumin showed a fast transient (<10 min) enhancement, which was further augmented by a peptide stabilizing the active metarhodopsin II conformation. The data suggest a direct release of 1 molecule of bound PS per rhodopsin into the outer leaflet and subsequent redistribution between the two leaflets. SL-PE and SL-PC showed more complex kinetics, in both cases consistent with a prolonged period of reduced extraction (2 phospholipids per rhodopsin in each case). The different phases of SL-PL reorganization after illumination may be related to the formation and decay of the active rhodopsin species and to their subsequent regeneration process.

Transforming growth factor-beta1 induces desmoplasia in an experimental model of human pancreatic carcinoma

Proliferation of fibrotic tissue (desmoplasia) is one of the hallmarks of several epithelial tumors including pancreatic adenocarcinoma. This tissue reaction may be deleterious or advantageous to the host or tumor. In a systematic analysis, we identified two growth factors expressed by human pancreatic carcinoma cells that are positively correlated with the ability to induce fibroblast proliferation both in vitro and in vivo, i.e., transforming growth factor (TGF)-beta1 and fibroblast growth factor-2. Here we demonstrate that the overexpression of TGF-beta1 induced up-regulation of matrix proteins and growth factors in the TGFbeta1-transfected pancreatic tumor cells. Furthermore, transfection of PANC-1 cells induces the same change in fibroblasts in either cocultivation experiments or when they are grown in conditioned medium from TGF-beta1-transfected PANC-1 cells. TGF-beta1-transfected pancreatic tumor cells induced a rich stroma after orthotopical transplantation in the nude mouse pancreas. The transfer of a single growth factor, TGF-beta1, conveys the ability to induce a fibroblast response similar to that seen in desmoplasia in human pancreatic adenocarcinoma. This effect cannot only be attributed to direct effects of TGF-beta1 but also results from the up-regulation of several other factors including collagen type I, connective tissue growth factor, and platelet-derived growth factor.

[Hyperthyroidism in early childhood and a very rare variant of glutaric aciduria: coincidence or causal relation?]

Hyperthyrosis is a rare disease in early childhood typically characterized by tachycardia, restlessness, elevated body temperature, failure to thrive, diarrhoea, goiter and a tendency to hyperglycaemia. A 3-year old boy presented with typical symptoms of thyrotoxicosis accompanied by ketotic hypoglycemia and excessively high glutaric acid excretion. To our knowledge this association has so far not been described. Specific defects responsible for glutaric aciduria types I & II were excluded. Our patient suffered from glutaric aciduria type III which was described once and is characterized by mild metabolic signs.

Critical dynamics of gelation

Shear relaxation and dynamic density fluctuations are studied within a Rouse model, generalized to include the effects of permanent random crosslinks. We derive an exact correspondence between the static shear viscosity and the resistance of a random resistor network. This relation allows us to compute the static shear viscosity exactly for uncorrelated crosslinks. For more general percolation models, which are amenable to a scaling description, it yields the scaling relation k=straight phi-beta for the critical exponent of the shear viscosity. Here beta is the thermal exponent for the gel fraction, and straight phi is the crossover exponent of the resistor network. The results on the shear viscosity are also used in deriving upper and lower bounds on the incoherent scattering function in the long-time limit, thereby corroborating previous results.

PCR detection and evidence of shedding of porcine circovirus type 2 in boar semen

An experimental study was conducted to evaluate the potential presence of porcine circovirus type 2 (PCV2) in the semen of infected boars. Four mature boars were inoculated intranasally with PCV2 isolate LHVA-V53 propagated on PK15 cells. Two boars inoculated with the supernatant of noninfected PK15 cells were kept as controls. Serum samples were collected from all boars at 4, 7, 11, 13, 18, 21, 25, 28, 35, and 55 days postinoculation (dpi) and from the four PCV2-infected boars at 90 dpi. Samples were tested for the presence of antibodies to PCV2 by an indirect immunofluorescence assay and for the presence of PCV2 DNA by PCR and nested PCR. Semen samples were collected from all six boars at 5, 8, 11, 13, 18, 21, 25, 28, 33, and 47 dpi and tested for the presence of PCV2 DNA by a nested PCR assay. Antibodies to PCV2 could be detected as early as 11 dpi in one boar, and all four infected boars were found positive for PCV2 antibodies by 18 dpi. Thereafter all infected boars remained positive for antibodies to PCV2 until 90 dpi. Analysis of serum samples by nested PCR demonstrated the presence of PCV2 DNA as early as 4 dpi in three of four infected boars. Serum samples from all infected boars were positive for PCV2 DNA from 11 dpi until 35 dpi but were negative at 90 dpi. PCV2 DNA was detected as soon as 5 dpi in the semen of two infected boars and intermittently thereafter in the semen of all four infected boars. The semen of two infected boars was positive for PCV2 DNA at 47 dpi. Following infection, PCV2 DNA can be detected in semen concurrently with the presence of PCV2 DNA and antibodies in the serum. The present study suggests that PCV2 may be shed intermittently in the semen of infected boars.

Conservation of the sequence and temporal expression of let-7 heterochronic regulatory RNA

Two small RNAs regulate the timing of Caenorhabditis elegans development. Transition from the first to the second larval stage fates requires the 22-nucleotide lin-4 RNA, and transition from late larval to adult cell fates requires the 21-nucleotide let-7 RNA. The lin-4 and let-7 RNA genes are not homologous to each other, but are each complementary to sequences in the 3' untranslated regions of a set of protein-coding target genes that are normally negatively regulated by the RNAs. Here we have detected let-7 RNAs of approximately 21 nucleotides in samples from a wide range of animal species, including vertebrate, ascidian, hemichordate, mollusc, annelid and arthropod, but not in RNAs from several cnidarian and poriferan species, Saccharomyces cerevisiae, Escherichia coli or Arabidopsis. We did not detect lin-4 RNA in these species. We found that let-7 temporal regulation is also conserved: let-7 RNA expression is first detected at late larval stages in C. elegans and Drosophila, at 48 hours after fertilization in zebrafish, and in adult stages of annelids and molluscs. The let-7 regulatory RNA may control late temporal transitions during development across animal phylogeny.

Tetrameric indium trichloride, a new modification of a widely used compound

The title compound, hexa-mu-chloro-1:2kappa(4)Cl;2:3kappa(4)Cl;3:4kappa(4) Cl-hexachlor o-1kappa(2)Cl,2kappaCl,3kappaCl, 4kappa(2)Cl-hexakis(diethylamine)-1kappa(2)N,2kappa N,3kappaN, 4kappa(2)N-tetraindium(III), [(InCl(3))(4)(Et(2)NH)(6)] or [In(4)Cl(12)(C(4)H(11)N)(6)], lies about an inversion centre and consists of four octahedrally coordinated In centres linked by bridging Cl atoms to form three four-membered In(2)Cl(2) rings.

Bone marrow "micrometastases" of epithelial tumors: detection and clinical relevance

The detection and elimination of "micrometastases" or, more precisely, isolated disseminated tumor cells or minimal residual disease is one of the main current topics in clinical oncology. Immunocytochemical and molecular, polymerase chain reaction (PCR) based methods are the preferred methods. Bone marrow as a mesenchymal organ and a frequent location for distant metastases is very suitable to study isolated disseminated tumor cells. Under optimal conditions one tumor cell among one million mononuclear bone marrow cells can be detected by immunocytochemistry or molecular methods. The specificity, however, varies significantly depending on the assay conditions used by each individual group, with false positive rates below 1% and over 80% reported. Immunocytochemistry with antibodies against different epithelial markers has shown that the presence of isolated disseminated tumor cells in bone marrow is an independent prognostic variable in breast, colorectal, gastric, and non-small cell lung cancer. Due to the lack of a standardized assay, however, comparison of the results between different groups is very difficult. Before the assessment for isolated disseminated tumor cells in bone marrow or other organs can be transferred into routine clinical practice, standardized methods have to be developed which must be tested in multicenter prospective trials.

External quality control program for inter-laboratory quality control

BACKGROUND

The accuracy and precision of tumor marker testing is of high clinical importance requiring the implementation of effective quality control procedures in the diagnostic laboratory. An external quality control program including an inter-laboratory comparison could be of help in improving the quality of test results.

MATERIALS AND METHODS

Laboratories using BIOREF reference material sent their routine internal quality control results of each monthly control period to the evaluation center for statistical analysis and inter-laboratory comparison.

RESULTS

The inter-laboratory comparison showed that the mean values of test results obtained by different laboratories can vary considerably especially when different test kits are used. A comparison of test results of laboratories using the same test kit showed much better correlation but discrepancies of coefficients of variation between these laboratories were still observed.

CONCLUSION

An external quality control program revealed problems in the accuracy and precision of tumor marker test results in the individual laboratory, which could serve as a basis for the improvement of test performance.

Line shapes in triple-resonance ionization spectroscopy

Line shapes in high-resolution triple-resonance ionization spectroscopy have been calculated and compared with experimental measurements on the 4s2 1S0 --> 4s4p 1P1 --> 4s4d 1D2 --> 4snf 1F3 --> Ca+ system of calcium. Calculations based on the density matrix formalism integrated the fundamental equations over experimental atomic angular and velocity distributions and laser intensity profiles. The measurements reveal and confirm all predicted structures arising from the complex coupling of four atomic states with three laser fields and the Doppler distribution of the atomic ensemble. Effects of different laser beam geometries on the line shapes have been investigated. The agreement between calculated and experimental spectra is generally good over a dynamic range of 10 orders of magnitude. Thus these calculations can accurately predict optical isotopic selectivity in multistep resonance ionization, with a value of S(opt) approximately 10(10) expected for detection of the ultratrace isotope 41Ca.