Simultaneous reconstruction of activity and attenuation for PET/MR

Medical investigations targeting a quantitative analysis of the position emission tomography (PET) images require the incorporation of additional knowledge about the photon attenuation distribution in the patient. Today, energy range adapted attenuation maps derived from computer tomography (CT) scans are used to effectively compensate for image quality degrading effects, such as attenuation and scatter. Replacing CT by magnetic resonance (MR) is considered as the next evolutionary step in the field of hybrid imaging systems. However, unlike CT, MR does not measure the photon attenuation and thus does not provide an easy access to this valuable information. Hence, many research groups currently investigate different technologies for MR-based attenuation correction (MR-AC). Typically, these approaches are based on techniques such as special acquisition sequences (alone or in combination with subsequent image processing), anatomical atlas registration, or pattern recognition techniques using a data base of MR and corresponding CT images. We propose a generic iterative reconstruction approach to simultaneously estimate the local tracer concentration and the attenuation distribution using the segmented MR image as anatomical reference. Instead of applying predefined attenuation values to specific anatomical regions or tissue types, the gamma attenuation at 511 keV is determined from the PET emission data. In particular, our approach uses a maximum-likelihood estimation for the activity and a gradient-ascent based algorithm for the attenuation distribution. The adverse effects of scattered and accidental gamma coincidences on the quantitative accuracy of PET, as well as artifacts caused by the inherent crosstalk between activity and attenuation estimation are efficiently reduced using enhanced decay event localization provided by time-of-flight PET, accurate correction for accidental coincidences, and a reduced number of unknown attenuation coefficients. First results achieved with measured whole body PET data and reference segmentation from CT showed an absolute mean difference of 0.005 cm⁻¹ (< 20%) in the lungs, 0.0009 cm⁻¹ (< 2%) in case of fat, and 0.0015 cm⁻¹ (< 2%) for muscles and blood. The proposed method indicates a robust and reliable alternative to other MR-AC approaches targeting patient specific quantitative analysis in time-of-flight PET/MR.

Abstract PD01-06: Activation of the Insulin-Like Growth Factor Pathway Distinguishes African American from European American Patients with Triple-Negative Breast Cancer by Gene Expression Profiling

Background: Triple-negative breast cancer (TNBC) is characterized by high histologic grade, high rates of distant recurrence and a poor overall prognosis. Treatment options are limited due to the lack of specific targets such as hormone receptors or HER2 which drive other breast cancer subtypes. Epidemiological studies show a markedly higher prevalence of TNBC in young women of African ancestry. In this study we sought to identify transcriptional modules that are differentially regulated between African American (AA) and European American (EA) women. Methods: A hospital-based cohort of 130 breast cancer patients diagnosed between 1985 and 2007 was selected by an institutional pathology database (CoPath) search for invasive, triple-negative breast cancer and enriched for patients of African American ethnicity. Racial distribution 47% AA, 33% EA, 8% Hispanic and 12% other or unknown. Clinical data was extracted from the Yale and Bridgeport Hospitals Tumor Registry following IRB approval. Invasive disease was identified on H&E sections and an average of 3 tissue cores from FFPE blocks were subjected to RNA extraction using the RecoverAll Total Nucleic Acid Isolation kit (Applied Biosystems) following the manufacturer's protocol. The extracted material was hybridized to Whole Genome-DASL assays (Illumina). Statistical analysis of gene expression data was carried out using Bioconductor/R software. A set of relevant signatures was selected by enrichment analysis of modules identified by principal component analysis. Signature scores were computed as Pearson correlation between the signature vector of gene contributions and each sample's expression profile for these genes. Results: African American patients show a significantly higher activation score for a 273-gene Insulin-like Growth Factor 1 signature compared with European American patients (stage-adjusted p=0.0006). Similarly, samples from AA patients show higher scores in a BRCA 1 mutant signature defined by van ‘t Veer and colleagues in 2002 (p=0.001) and in a luminal progenitor (CD49f+EpCAM+) signature from Lim et al. (2009) (p=0.01). The Genomic Grade Index (GGI, Sotiriou et al. 2006) in samples from AA patients was also found to be significantly elevated (p=0.0007). Conclusions: Our findings indicate significant activation of the IGF pathway in AA compared to EA patients with TNBC. The 273-gene IGF signature was associated with poor differentiation and high proliferation in an independent cohort, which is in agreement with the high GGI score observed in AA patients. BRCA1 mutant-like and luminal progenitor-like properties in AA tumor samples further support this hypothesis as they both are related to basal-like histology which constitutes an aggressive subgroup of triple-negative tumors. These data suggest that African American patients may benefit from IGF pathway inhibiting drugs.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD01-06.

Genome-Wide Profiling of Archived Material from CALGB 9840 and 9342 for Paclitaxel (P) and Trastuzumab (T) Response Biomarkers Using Gene Expression and Copy Number Analysis

Background:Emerging data suggest that RNA obtained from formalin-fixed, paraffin-embedded (FFPE) tissue can produce reliable gene expression profiles. Archived material from two taxane monotherapy studies, CALGB 9342 (comparison of 3 doses of P) and 9840 (weekly vs. q3 week P)were profiled for gene expression and DNA copy number.Methods: A total of 238 patients had primary tumor blocks available from a combined sample size of 680. DNA and RNA was extracted from 1.5mm punch cores and the Ambion Recover-All kit™. quality was measured by spectrophotometric analysis, Bioanalyzer RNA Integrity Number (RIN), and housekeeping genes (RPL13A and Actin). A custom DASL™ array containing 779 genes in two-fold redundancy was designed with genes selected to represent the PAM50 intrinsic subtypes, the Oncotype Dx Score, the Netherlands prognostic signature and the genes most frequently found on recurrent breast cancer amplicons. Several methods for identifying outliers were evaluated, including principal components analysis, pairwise correlations as well as the reproducibility of the platform based on replicate samples.Results: Adequate RNA was obtained from 237/238 of these cases which ranged in age from 12-18 years. Of these, 215/237DASL arrays passed further quality control measures. Adequate DNA for CGH was obtained from 227/238 samples. Analysis of PAM50 intrinsic subtypes showed an excess of basal-like tumors (30%) in the primary tumors of this metastatic cohort compared with expected frequency in an early stage population. Luminal A tumors were less frequent than expected (20%). Patients with basal-like tumors did far worse than other tumor types for both PFS on P (p=0.015) and OS (p=2.7X10-6), which persisted in multivariable analysis (p=0.0047), however the interaction term was not significant (Wald p=0.26). While basal-like tumors had similar PFS and OS on both weekly and q3 week P, luminal A tumors appear to achieve more benefit from weekly P (p= 0.0041).The HER2-enriched expression subtype had a similar prognosis to Luminal A and B tumors. This appeared to be due to the presence of T, as the addition of this agent improved PFS (p=0.026) and OS (p=2.0X10-4). Of note, some centrally confirmed HER2 FISH amplified tumors were classified into luminal A, B, and basal-like subtypes. These tumors have similar prognoses to the overall group, for example the basal-like and HER2 tumors had a poor prognosis despite T (p=0.00086). This suggests that HER2 FISH positive tumors may behave based on the underlying tumor subtype. Sawtooth genomes (45% vs 15%) were more frequent than predicted by an early stage tumor dataset as were simplex genomes (3% vs 24%). HER2 by FISH and CGH were highly concordant suggesting data on gene amplification from this platform is robust.Conclusions: Gene expression and copy number profiling of FFPE material from archived tumor blocks (&gt;10 years) produces quality data for biomarker discovery in CALGB clinical trial datasets. These tools allow discovery of novel patterns of gene expression and genomic aberrations that are associated with differential response to P and T. Further studies using these platforms should be performed.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4032.

The malignant wound assessment tool: a validation study using a Delphi approach

Malignant wounds, caused by the direct invasion of cancer into the skin, occur in cancer patients with primary skin tumours and as cutaneous metastasis in approximately 10% of patients with metastatic internal malignancies. Malignant wounds have a profound impact on patients, family members and health care providers. The assessment of the patient with malignant wounds can be complex and there is no widely accepted, consistent approach. Valid, descriptive survey research methods were used to develop the Malignant Wound Assessment Tool (MWAT). The authors developed two versions of the MWAT: a brief clinical version (MWAT-C) and a more detailed research version (MWAT-R). Domains include clinical wound features, physical effects and emotional and social impacts of the wound. The two tools underwent content and construct validity testing using a Delphi process. An international panel of professionals with clinical or research expertise related to malignant wounds was formed. Panelists participated in two rounds of review for each tool. Development and face validity testing of the MWAT-C and MWAT-R tools through the Delphi process have resulted in tools ready for clinical application and will support clinical and research activities to improve care for patients with this devastating condition.

Differential response of human naive and memory/effector T cells to dendritic cells infected by respiratory syncytial virus

In vitro studies have contributed substantially to the understanding of immunopathology of respiratory syncytial virus (RSV)-mediated disease. In the present study we compared the effect of RSV-infected dendritic cells on the time-course of the primary and memory/effector T cell response in vitro. Cultures with uninfected dendritic cells known to elicit T helper 2 (Th2) responses and with polyinosinic-polycytidylic acid (poly-IC)-stimulated dendritic cells known to elicit Th1 responses served as controls. At day 1 after stimulation there was a high proportion of interleukin (IL)-2 and tumour necrosis factor (TNF)-alpha-producing T cells with no difference in number of producing T cells as well as concentration of secreted cytokines between RSV-infected and control cultures. However, up to day 3 generation of IFN-gamma was reduced markedly. In addition, there was a reduced proliferation in RSV cultures. At day 7 the RSV-treated cultures showed a preponderance of IL-4 generation. At days 21-24, after three rounds of restimulation, memory/effector T cells matured under the influence of RSV were still not fully polarized but in contrast to the primary response displayed a predominance of Th1 cytokines. Contact with RSV-infected HEp-2 cells inhibited proliferation of T cells; memory effector T cells were less sensitive to contact inhibition than naive T cells. In addition, RSV inhibited the stimulated rearrangement of cortical actin more effectively in naive compared to memory T cells. In summary, we have shown that RSV infection of dendritic cells has a distinct modulatory effect on the primary response and a less pronounced effect on the memory response.

Effect of CT-based attenuation correction on uptake ratios in skeletal SPECT

The AIM of this study was to determine the clinical relevance of compensating SPECT data for patient specific attenuation by the use of CT data simultaneously acquired with SPECT/CT when analyzing the skeletal uptake of polyphosphonates (DPD). Furthermore, the influence of misregistration between SPECT and CT data on uptake ratios was investigated.

METHODS

Thirty-six data sets from bone SPECTs performed on a hybrid SPECT/CT system were retrospectively analyzed. Using regions of interest (ROIs), raw counts were determined in the fifth lumbar vertebral body, its facet joints, both anterior iliacal spinae, and of the whole transversal slice. ROI measurements were performed in uncorrected (NAC) and attenuation-corrected (AC) images. Furthermore, the ROI measurements were also performed in AC scans in which SPECT and CT images had been misaligned by 1 cm in one dimension beforehand (ACX, ACY, ACZ).

RESULTS

After AC, DPD uptake ratios differed significantly from the NAC values in all regions studied ranging from 32% for the left facet joint to 39% for the vertebral body. AC using misaligned pairs of patient data sets led to a significant change of whole-slice uptake ratios whose differences ranged from 3,5 to 25%. For ACX, the average left-to-right ratio of the facet joints was by 8% and for the superior iliacal spines by 31% lower than the values determined for the matched images (p < 0.05).

CONCLUSIONS

AC significantly affects DPD uptake ratios. Furthermore, misalignment between SPECT and CT may introduce significant errors in quantification, potentially also affecting left-to-right ratios. Therefore, at clinical evaluation of attenuation-corrected scans special attention should be given to possible misalignments between SPECT and CT.

Polymorphisms in the xylosyltransferase genes cause higher serum XT-I activity in patients with pseudoxanthoma elasticum (PXE) and are involved in a severe disease course

BACKGROUND

Pseudoxanthoma elasticum (PXE) is a heritable connective tissue disorder caused by mutations in the ABCC6 gene. Fragmentation of elastic fibres and deposition of proteoglycans result in a highly variable clinical picture. The altered proteoglycan metabolism suggests that enzymes from this pathway function as genetic co-factors in the severity of PXE. Therefore, we propose the XYLT genes encoding xylosyltransferase I (XT-I) as the chain-initiating enzyme in the biosynthesis of proteoglycans and the highly homologous XT-II as potential candidate genes.

METHODS

We screened all XYLT exons in 65 German PXE patients using denaturing high performance liquid chromatography and analysed the influence of the variations on clinical characteristics.

RESULTS

We identified 22 variations in the XYLT genes. The missense variation p.A115S (XT-I) is associated with higher serum XT activity (p = 0.005). The amino acid substitution p.T801R (XT-II; c.2402C>G) occurs with significantly higher frequency in patients under 30 years of age at diagnosis (43% v 26%; p = 0.04); all PXE patients with this variation suffer from skin lesions compared to only 75% of the wild type patients (p = 0.002). c.166G>A, c.1569C>T, and c.2402C>G in the XYLT-II gene were found to be more frequent in patients with higher organ involvement (p = 0.04, p = 0.01, and p = 0.02, respectively).

CONCLUSIONS

Here we show for the first time that variations in the XYLT-II gene are genetic co-factors in the severity of PXE. Furthermore, the higher XT activity in patients with the exchange p.A115S (XT-I) indicates that this polymorphism is a potential marker for increased remodelling of the extracellular matrix.

Safety of St. John's Wort extract compared to synthetic antidepressants

The clinical efficacy of some standardized St. John's Wort extracts (SWEs) such as WS((R)) 5570, WS((R)) 5572 or LI 160 in the treatment of mild, moderate and severe major depression has been demonstrated in 38 controlled clinical trials and two recent meta-analyses. Sixteen post-marketing surveillance studies with such preparations, based on a total of 34,804 patients, recorded an incidence of adverse events (AEs) among patients between 0% and 6%. Of these studies, the four large-scale surveillance studies with a total of 14,245 patients recorded a rate of AEs ranging from 0.1% to 2.4% and a drop-out rate due to AEs of 0.1-0.9%. This is at least ten-fold lower than that recorded with synthetic antidepressants. AEs associated with SWE treatment were mild and transient in nearly all cases. As with synthetic antidepressants, pharmacokinetic interactions may occur occasionally as a result of activity changes of drug-metabolising and drug-transporting proteins, especially CYP 3A4 and P-gp. Risks to the patient are not caused by SWE but by drugs with a narrow therapeutic range. Consequently, SWE preparations should not be taken concurrently with other antidepressants, with coumarin-type anticoagulants, the immunosuppressants cyclosporine and tacrolimus, protease and reverse transcriptase inhibitors used in anti-HIV treatment or with certain antineoplastic agents. However, such cases are extremely rare and, with medical supervision, easily avoided. In conclusion, the safety of SWE must be considered more favourable than that of synthetic antidepressants.

Methadone in the management of intractable neuropathic noncancer pain

OBJECTIVE

To evaluate the role of methadone in the management of intractable neuropathic noncancer pain.

METHODS

A case series of 50 consecutive noncancer pain patients who were seen at a tertiary care centre and treated with oral methadone for a variety of intractable neuropathic pain states.

RESULTS

The mean age was 52.7 years and the mean duration of follow-up was 13.9 months. Post-discectomy nerve root fibrosis, complex regional pain syndrome, peripheral neuropathy and central spinal cord pain syndromes were the most common diagnoses. Over 90% had been treated with one or more tricyclic antidepressants and anticonvulsants and a similar number had received other adjuvant analgesics. All patients had failed treatment with one or more conventional opioid analgesics (mean 2.8) at a mean maximal morphine dose of 384 mg (or equivalents) per day. Twelve patients had failed spinal cord stimulation. Nineteen patients (38%) did not tolerate initial methadone titration or thought their pain was worse on methadone. Five patients (10%) declared initial benefit but required repetitive dose escalation and eventually became non-responders. Twenty-six patients (52%) reported mild (4), moderate (15), marked (6) or complete (1) pain relief and continued on methadone at a mean maintenance dose of 159.8 mg/day for a mean duration of 21.3 months. Fourteen patients (28%) reported improved function on methadone relative to previous treatments.

CONCLUSIONS

Methadone appears to have unique properties including N-methyl-D-aspartate antagonist activity that may make it especially useful in the management of intractable neuropathic pain. This observation needs to be tested in randomized, controlled trials.

Transmission line for improved RF safety of interventional devices

A new concept is proposed to improve the safety of transmission lines with respect to heating during RF transmission. It is based on the integration of transformers into the transmission line. The concept was applied to an active tracking device. Miniature transformers were designed, and two types of tracking devices were built based on a standard line and a transformer line. Temperature measurements were performed for both devices during high specific absorption rate (SAR) scanning, and the suppression of RF heating to a physiologically non-relevant level was demonstrated for the transformer device. The transmission properties of the transformer line were examined in simulations and RF measurements. Active tracking with the transformer device performed robustly in the phantom. Because of the favorable signal transmission properties of the tested device, it is expected that the concept can be applied to the construction of clinical devices for tracking and intravascular imaging, which are RF-safe under clinical SAR conditions. Since the transformer line has a large bandwidth, the concept may also be applied for RF-safe transmission of non-MR signals.

A safe transmission line for MRI

Magnetic resonance imaging (MRI) has been established as a reliable and safe imaging method for the human body. However, electric conductors, such as cables situated near or in the human body, should be avoided because induced currents in the cables can cause hazardous heating in the surrounding tissue. In this paper, a new principle for the design of a transmission line is introduced and demonstrated, which is capable of avoiding dangerous heating of cables. The principle is based on transformers placed along the line, splitting the long line into several short not resonant and thus safe sections. A transformer design is introduced along with the theoretical aspects for both the avoidance of the undesired induced currents and the reduction of signal attenuation. Furthermore, the design fulfills the geometrical requirements of the side lumen of a standard catheter. Matching networks, whose elements are determined by power matching, are used to reduce signal attenuation by the transformers. A prototype was built to validate both theory and the simulations. As demonstrated in this work, it is possible to build safe transmission lines for MRI, making applications such as active catheter tracking possible. We expect that even new applications, such as safe intravascular imaging will be possible in a safe manner in the future.

[Herbal drugs: luxury or basic therapy in federal insurance practice?]

Over the past 6 years SHI-accredited prescriptions for herbal medicinal products have decreased in Germany by around 40% (Social Health Insurance). However, this has not reduced overall drug expenditure for the statutory health insurers; in fact costs have increased more sharply than before. This development was recently explained by "Modernisation of Pharmacotherapy" which picked out 5 groups as examples. The present paper examines one of these examples, i.e. modern antidepressant therapy, and compares it with the results of recent studies and meta-analyses of herbal and synthetic preparations. Above all, the comparison for this indication revealed that the medication itself, independent of which group it belongs to, contributes merely one third of the treatment results whereas the remaining two thirds are contributed by therapists and their surroundings. Experienced physicians achieve virtually the same treatment results with suitable St. John's wort preparations as they do with modern synthetic antidepressants. Hence, medically supervised therapy with herbal medicinal products for suitable indications could avoid billions in development and treatment costs for supposedly innovative drugs. These savings would then benefit broader basic therapy.

Glutathione-S-transferase M1, M3, T1 and P1 polymorphisms and susceptibility to non-small-cell lung cancer subtypes and hamartomas

Polymorphic glutathione-S-transferase (GST) genes causing variations in enzyme activity may influence individual susceptibility to lung cancer. In this case-control study (consisting of 389 Caucasian lung cancer patients, including 151 adenocarcinomas (ACs) and 172 squamous cell carcinomas (SCCs), and 353 hospital control subjects without malignant disease, genotype frequencies for GSTM1, GSTM3, GSTP1 and GSTT1 were determined by polymerase chain reaction (PCR)/ restriction fragment length polymorphism (RFLP)-based methods. While adjusted odds ratios (ORs) indicated no significantly increased risk for lung cancer overall due to any single GST genotype, the risk alleles for GSTM1, GSTM3 and GSTP1 conferring reduced enzyme activity were present at higher frequency in SCC than in AC patients. This is consistent with a reduced detoxification of carcinogenic polycyclic aromatic hydrocarbons (PAHs) from cigarette smoke that are more important for the development of SCC than for AC. An explorative data analysis also identified statistically significantly increased ORs for the combinations GSTT1 non-null and GSTP1 GG or AG for lung cancer overall (OR 2.23, CI 1.11-4.45), and for SCC (OR 2.69, CI 1.03-6.99). For lung cancer overall, and especially among SCC patients, the GSTT1 null genotype was underrepresented (SCC 11.2% v. control subjects 19%, P = 0.026, OR 0.57, CI 0.30-1.06). Additionally, in 28 patients with hamartomas, the GSTT1 null genotype was also protective (P = 0.013), while GSTP1 variant allele carriers were overrepresented (OR 2.48, CI 1.06-6.51). In conclusion, GST genotypes may act differently, either by detoxifying harmful tobacco carcinogens and/or by eliminating lung cancer chemopreventive agents. The latter role for GSTT1 would explain the observed lower risk of SCC and hamartoma associated with GSTT1 null. Further confirmatory studies are required.

Haplotype variation and linkage disequilibrium in 313 human genes

Variation within genes has important implications for all biological traits. We identified 3899 single nucleotide polymorphisms (SNPs) that were present within 313 genes from 82 unrelated individuals of diverse ancestry, and we organized the SNPs into 4304 different haplotypes. Each gene had several variable SNPs and haplotypes that were present in all populations, as well as a number that were population-specific. Pairs of SNPs exhibited variability in the degree of linkage disequilibrium that was a function of their location within a gene, distance from each other, population distribution, and population frequency. Haplotypes generally had more information content (heterozygosity) than did individual SNPs. Our analysis of the pattern of variation strongly supports the recent expansion of the human population.

Altered DNA repair capacity and bleomycin sensitivity as risk markers for non-small cell lung cancer

DNA repair capacity in human peripheral blood lymphocytes was monitored by the repair rate of bleomycin-induced DNA damage using an alkaline single-cell gel electrophoresis assay (comet assay). DNA repair capacity, after 15 min repair time, in lymphocytes of non-small cell lung cancer patients (n = 160) and controls (n = 180) was 67% and 79.3%, respectively (p < 0.0004). Bleomycin sensitivity defined as the tail moment of bleomycin-treated peripheral blood lymphocytes, without allowing time for DNA repair, was significantly higher in lung cancer patients than in tumor-free hospital controls (p < 0.0001). There was no correlation, in either patient or control group, between the bleomycin sensitivity and DNA repair capacity with age or gender. The median values of DNA repair capacity and sensitivity in controls were used as the cut-off points for calculating odds ratios (OR). After adjustment for age, gender and smoking status, the cases vs. controls had reduced DNA repair capacity (OR = 2.1; 95% confidence limit [CL] 1.1-4.0) and increased bleomycin sensitivity (OR = 4; 95% CL 2.2-7.4). For current smokers, the adjusted risk associated with bleomycin sensitivity was 2.3 (95% CL 1.1-4.9). We conclude that our standard comet assay as a phenotypical repair test has sufficient sensitivity and rapidity allowing application to both native and cryopreserved lymphocytes. Bleomycin sensitivity and DNA repair capacity were found to be 2 independent susceptibility markers for non-small cell lung cancer, confirming similar investigations with different marker end points. The latter were much more time consuming than the method used in our study. Thus, the comet assay is more suitable for screening large numbers of individuals in epidemiological studies. Validation of this assay in large prospective studies for the identification of subjects at high risk for non-small cell lung cancer is now warranted.

Incidence and clinical relevance of the interactions and side effects of Hypericum preparations

Observational studies with preparations of St. John's wort have recorded an incidence of adverse events (AE) among those treated of between 1 and 3%. This is some ten times less than with synthetic antidepressants. The most common adverse events (1 per 300000 treated cases) among the spontaneous reports in the official register concern reactions of the skin exposed to light. Investigations in volunteers have shown that the threshold dose for an increased risk of photosensitisation is about 2-4 g/day of a usual commercial extract (equivalent to approximately 5-10 mg of the hypericin that causes the phenomenon). In view of the newly observed side effects and interactions, the following additional restrictions on use appear justified: as with all preparations in this group of indications, hypericum preparations must not be taken at the same time as other antidepressants. If co-medication with coumarin-type anticoagulants is unavoidable, it must only be undertaken provided the physician closely monitors clotting parameters. Co-medication with ciclosporin and indinavir, and for the time being, other protease inhibitors used in anti-HIV treatment, is absolutely contraindicated. Without exception, all preparations of St. John's wort must only be available through pharmacies.

Relevance of N-acetyltransferase 1 and 2 (NAT1, NAT2) genetic polymorphisms in non-small cell lung cancer susceptibility

The highly polymorphic N-acetyltransferases (NAT1 and NAT2) are involved in both activation and inactivation reactions of numerous carcinogens, such as tobacco derived aromatic amines. The potential effect of the NAT genotypes in individual susceptibility to lung cancer was examined in a hospital based case-control study consisting of 392 Caucasian lung cancer patients [152 adenocarcinomas, 173 squamous cell carcinomas (SCC) and 67 other primary lung tumours] and 351 controls. In addition to the wild-type allele NAT1*4, seven variant NAT1 alleles (NAT1*3, *10, *11, *14, *15, *17 and *22) were analysed. A new method based on the LightCycler (Roche Diagnostics Inc.) technology was applied for the detection of the polymorphic NAT1 sites at nt 1088 and nt 1095. The NAT2 polymorphic sites at nt 481, 590, 803 and 857 were detected by polymerase chain reaction-restriction fragment length polymorphism or LightCycler. Multivariate logistic regression analyses were performed taking into account levels of smoking, age, gender and occupational exposure. An increased risk for adenocarcinoma among the NAT1 putative fast acetylators [odds ratio (OR) 1.92 (1.16-3.16)] was found but could not be detected for SCC or the total case group. NAT2 genotypes alone appeared not to modify individual lung cancer risk, however, individuals with combined NAT1 fast and NAT2 slow genotype had significantly elevated adenocarcinoma risk [OR 2.22 (1.03-4.81)] compared to persons with other genotype combinations. These data clearly show the importance of separating different histological lung tumour subtypes in studies on genetic susceptibility factors and implicate the NAT1*10 allele as a risk factor for adenocarcinoma.

Rapid screening assay for mutagen sensitivity and DNA repair capacity in human peripheral blood lymphocytes

Individual susceptibility to carcinogens, an important determinant of disease risk, is influenced by host factors such as the ability to repair DNA lesions. In order to identify subjects who are at high risk, we have developed a microgel electrophoresis assay for use in molecular epidemiological studies. The assay was validated in a pilot case-control study: Peripheral blood lymphocytes were collected from 100 patients with lung cancer and 110 control patients without cancer and from the same hospital, and stored at -80 degrees C. After thawing, phytohaemagglutinin-stimulated cells were treated with bleomycin at 20 microg/ml for 30 min and the extent of DNA damage and DNA repair capacity were determined by microgel electrophoresis. Peripheral blood lymphocytes from patients with lung cancer were significantly more sensitive to mutagens than those from controls and showed reduced DNA repair capacity (both P < 0.001). Both endpoints were independent risk factors for smoking-related lung cancer. Repeated analysis of peripheral blood lymphocytes from the same individual demonstrated good reproducibility of the assay. Cryopreservation of the lymphocytes for less than or = 12 months did not significantly affect their sensitivity. Our standardized microgel electrophoresis assay is suitable for determining individual sensitivity to mutagens and DNA repair capacity: it is sensitive and faster than cytogenetic assays, and can be applied to native and cryopreserved peripheral blood lymphocytes.

hOGG1 polymorphism and loss of heterozygosity (LOH): significance for lung cancer susceptibility in a caucasian population

Oxidative damage is implicated in several chronic diseases including cancer. 8-Hydroxyguanine (8-oxoG) is one of the major promutagenic DNA lesions, which is produced by reactive oxygen species, causes G:C to T:A transversions and is excised by OGG1, an 8-oxoG specific DNA glycosylase/AP-Lyase. In a nested case-control study, gDNA from 105 Caucasian primary non-small cell lung cancer cases and 105 matched controls was screened for 6 possible new polymorphic sites in the human OGG1 gene, detected previously mainly in tumour tissue. The previously described Ser(326)Cys polymorphism was found to be common (allele frequency 0.22) in Caucasians. However, no major difference in Ser(326)Cys genotype distribution could be detected between cases and controls. Two 5;-end polymorphisms previously found in Japanese as well as Arg(131)Gln could not be detected in this population. An Ala(85)Ser polymorphism was found in 2 controls, whereas Arg(46)Gln was detected in only 1 case. As the hOGG1 gene is mapped (3p26.2) to a region frequently lost in primary lung tumours, the frequency of loss of heterozygosity (LOH) was investigated. Forty-three percent of the studied lung tumours exhibited loss of one of the hOGG1 alleles. The wt Ser(326) allele was not predominantly lost in our sample set, which suggests a minor role of this polymorphism in tumourgenesis. Our results show that LOH at the hOGG1 gene locus is a very common occurrence in lung tumourgenesis, possibly leading to increased mutational damage due to ROS in smokers. However, the hOGG1 polymorphisms studied are probably not major contributors to individual lung cancer susceptibility in Caucasians.

[St. Johns wort extract as plant antidepressant]

In 1998 a standardized hypericum extract has been approved in Austria and Germany for treatment of mild and moderate depression. The efficacy has been already recognized since 1984 from the German Health Authorities based on traditional knowledge. However, this has been substantiated in the subsequent years in controlled clinical trials. Twenty of these studies including a total of 1787 patients have been filed, among them ten older studies in which hypericum was extracted with ethanol compared to newer studies in which the extract was methanol (LI 160). In the past ten years several controlled clinical trials have been conducted compared with placebo as well as synthetic antidepressants. These studies have shown that the effective dosage is within a range of 600-900 mg extract. The side effects are substantially fewer than with synthetic antidepressants and range within 3%. The most important risk is photosensitization, which is however without clinical relevance in the recommended dosages. Recent pharmacological studies revealed that hypericum extracts have a similar mechanism of action like the selective serotonin reuptake inhibitors (SSRI), however, very likely to a smaller extent.

hOGG1 polymorphism and loss of heterozygosity (LOH): significance for lung cancer susceptibility in a caucasian population

Oxidative damage is implicated in several chronic diseases including cancer. 8-Hydroxyguanine (8-oxoG) is one of the major promutagenic DNA lesions, which is produced by reactive oxygen species, causes G:C to T:A transversions and is excised by OGG1, an 8-oxoG specific DNA glycosylase/AP-Lyase. In a nested case-control study, gDNA from 105 Caucasian primary non-small cell lung cancer cases and 105 matched controls was screened for 6 possible new polymorphic sites in the human OGG1 gene, detected previously mainly in tumour tissue. The previously described Ser(326)Cys polymorphism was found to be common (allele frequency 0.22) in Caucasians. However, no major difference in Ser(326)Cys genotype distribution could be detected between cases and controls. Two 5;-end polymorphisms previously found in Japanese as well as Arg(131)Gln could not be detected in this population. An Ala(85)Ser polymorphism was found in 2 controls, whereas Arg(46)Gln was detected in only 1 case. As the hOGG1 gene is mapped (3p26.2) to a region frequently lost in primary lung tumours, the frequency of loss of heterozygosity (LOH) was investigated. Forty-three percent of the studied lung tumours exhibited loss of one of the hOGG1 alleles. The wt Ser(326) allele was not predominantly lost in our sample set, which suggests a minor role of this polymorphism in tumourgenesis. Our results show that LOH at the hOGG1 gene locus is a very common occurrence in lung tumourgenesis, possibly leading to increased mutational damage due to ROS in smokers. However, the hOGG1 polymorphisms studied are probably not major contributors to individual lung cancer susceptibility in Caucasians.

[Incidence and clinical relevance of interactions and side-effects of hypericum preparations]

Observational studies with preparations of St. John's wort have recorded an incidence of adverse events (AE) among those treated of between 1 and 3%. This is some ten times less than with synthetic antidepressants. The most common adverse events (1 per 300,000 treated cases) among the spontaneous reports in the official register concern reactions of the skin exposed to light. Investigations in volunteers have shown that the threshold dose for an increased risk of photosensitisation is about 2-4 g/day of a usual commercial extract (equivalent to approximately 5-10 mg of the hypericin that causes the phenomenon). In view of the newly observed side effects and interactions, the following additional restrictions on use appear justified: as with all preparations in this group of indications, hypericum preparations must not be taken at the same time as other antidepressants. If co-medication with coumarin-type anticoagulants is unavoidable, it must only be undertaken provided clotting parameters are closely monitored by the physician. Co-medication with cyclosporin and indinavir, and for the time being, other protease inhibitors used in anti-HIV treatment, is absolutely contraindicated. Without exception, all preparations of St. John's wort must only be available through pharmacies.

Glucose-regulated anaplerosis and cataplerosis in pancreatic beta-cells: possible implication of a pyruvate/citrate shuttle in insulin secretion

The hypothesis proposing that anaplerosis and cataplerosis play an important role in fuel signaling by providing mitochondrially derived coupling factors for stimulation of insulin secretion was tested. A rise in citrate coincided with the initiation of insulin secretion in response to glucose in INS-1 beta-cells. The dose dependence of glucose-stimulated insulin release correlated closely with those of the cellular contents of citrate, malate, and citrate-derived malonyl-CoA. The glucose-induced elevations in citrate, alpha-ketoglutarate, malonyl-CoA, and the 3-[4,5-dimethylthiazol-2yl]-2,5-diphenyltetrazolium reduction state, an index of beta-cell metabolic activity, were unaffected by the Ca2+ chelator EGTA. Glucose induced a rise in both mitochondrial and cytosolic citrate and promoted efflux of citrate from the cells. The latter amounted to approximately 20% of glucose carbons entering the glycolytic pathway. Phenylacetic acid, a pyruvate carboxylase inhibitor, reduced the glucose-induced rise in citrate in INS-1 cells and insulin secretion in both INS-1 cells and rat islets. The results indicate the feasibility of a pyruvate/citrate shuttle in INS-1 beta-cells, allowing the regeneration of NAD+ in the cytosol and the formation of cytosolic acetyl-CoA, malonyl-CoA, and NADPH. The data suggest that anaplerosis and cataplerosis are early signaling events in beta-cell activation that do not require a rise in Ca2+. It is proposed that citrate is a signal of fuel abundance that contributes to beta-cell activation in both the mitochondrial and cytosolic compartments and that a major fate of anaplerotic glucose carbons is external citrate.

The psychodynamic and pharmacodynamic effects of drugs: a differentiated evaluation of the efficacy of phytotherapy

The therapeutic usefulness of medicines is nowadays usually measured in terms of parameters devised in the artificial surroundings of a double blind clinical trial. The difference between the active drug and the placebo is accepted as being the same as the desired overall effect. Yet, when applied to whole categories of medicines, this yardstick can be misleading, as has become apparent from the discussion which has recently arisen regarding the genuine and the illusory pharmacodynamic effects of synthetic antidepressants. Differentiated analysis of a representative number of placebo-controlled studies has shown that when used for depressive conditions, the psychodynamic components contribute far more to the overall effect than do the pharmacodynamic components. In this respect, modern synthetic antidepressants are no better than Hypericum products of plant origin. Among other things, this means that for depressive states and similar indications, the safety, tolerability and acceptability of a medicine must be given much greater weight than its pharmacodynamic effects as assessed simply by testing against a placebo. The quantification of the two therapeutic components, as can be accomplished by a placebo-controlled drug trial, has revealed that the overall outcome of therapy for various important indications of this kind is attributable predominantly to the psychodynamic component. It may reasonably be assumed that the contribution made by the pharmacodynamic effects to the overall therapeutic response will amount to only about 20-50%. This raises questions regarding the clinical relevance and economic value of placebo-controlled studies. When assessing data on drug efficacy for the purpose of licensing applications, greater attention should be given to this reality.

[Intermittent positive pressure ventilation in post tuberculosis syndrome]

Pulmonary tuberculosis sequelae with chronic respiratory failure is a clinical picture that is often mentioned, but seldom separately described, in connection with noninvasive ventilation in the case of acute or chronic respiratory failure. We report on the functional data and the ventilation of 26 patients. The patient group is characterized by great chronological latency between the start of pulmonary tuberculosis and the development of respiratory illness. Acute or chronic respiratory failure with this clinical entity should be treated in the form of noninvasive positive pressure ventilation.

[Ventilatory failure in COPD: follow-up under intermittent positive pressure ventilation (IPPV)]

Effectiveness of IPPV in COPD is controversial. We examine the course of 29 patients with longterm IPPV (19 male, 10 female, age 60.3 years, BMI 23.7, FEV1 mean 22% predicted, PaCO2 mean 67 mmHg). PaCO2 is significantly by IPPV reduced. Patients are followed for 2 to 48 months (mean 16.5). Five stop IPPV (1 bilateral lung transplantation, 1 lung volume reduction surgery, 3 non-compliance), 8 die of respiratory failure, 5 of non-respiratory causes (non-RI) (3 tumor, 2 cardiovascular), and 10 survive (SV, 20.5 months). No difference in survival is observed between non-RI and SV. Weight increase by +5% is seen in SV more frequently, lung function is worse in RI, especially in weaning pts., hospital days are less frequent in SV and non-RI. Probability of survival is 70% at 1 year, 57% at 2 years, and 23% at 3 years, and is seriously influenced by non-RI. Our results are influenced by the high number of non-RI, the quitting of IPPV, and the primary inclusion of tumour pts. Still a high number of deaths by RI leads us to the conclusion that IPPV may be helpful for palliation, bridging before surgery and in subgroups who still have to be defined.

[Course of pulmonary hemodynamics in intermittent ventilation]

Patients with chronic respiratory failure often show an elevated pulmonary vascular resistance. We examined in a prospective study with the follow-up of patients with intermittent non-invasive ventilation (nISB) and pulmonary hypertension using dobutamine stress echocardiography. The data show that ISB lowers the pressure in all patients, more in patients with restrictive diseases, due to thoracic deformities, than in patients with COPD.

[High dose St. John's wort extract as a phytogenic antidepressant]

In 1998 a special standardized high-dose hypericum extract has been approved in Austria and Germany for treatment of mild and moderate depression. The efficacy has been already recognized since 1984 from the German Health Authorities based on traditional knowledge. However, this has been substantiated in the subsequent years in controlled clinical trials. 20 of these studies including a total of 1,787 patients have been filed, among them 10 older studies in which hypericum was extracted with ethanol compared to newer studies in which the extract was methanol (LI 160). In the past 10 years several controlled clinical trials have been conducted compared with placebo as well as synthetic antidepressants. These studies have shown that the effective dosage is within a range of 600 to 900 mg extract. The side effects are substantially fewer than with synthetic antidepressants and range within 3%. The most important risk is photosensitization, which is however without clinical relevance in the recommended dosages. Recent pharmacological studies revealed that hypericum extracts have a similar mechanism of action like the selective serotonin reuptake inhibitors (SSRI), however, very likely to a smaller extent.

Outpatient use of low molecular weight heparin (Dalteparin) for the treatment of deep vein thrombosis of the upper extremity

Upper extremity deep vein thrombosis (DVT) is now recognized as a major cause of morbidity and mortality. There is little information regarding the most effective treatment of this condition. We report a prospective cohort study of the use of low molecular weight heparin (LMWH) in the outpatient management of upper extremity DVT. Forty-six patients were managed as outpatients for objectively documented upper extremity DVT with dalteparin (200 aXa u/kg), for a minimum of five days. Warfarin was usually initiated on the first day with a target INR of 2.0-3.0. Most patients had an underlying malignancy or a history of a central line. All patients were followed for 12 weeks from diagnosis. Only one patient had a major bleed. No patients developed pulmonary emboli. One patient had a recurrence of DVT during the treatment with LMWH with extension of the existing thrombus. Seven patients died, all due to their underlying disease. This study supports the safety and effectiveness of dalteparin in the treatment of upper extremity DVT. Given that these patients were treated as outpatients, there is a potential for huge cost savings.

Maintenance of increased Bcl-2 expression in uterine leiomyomas after GnRH agonist therapy

OBJECTIVE

To compare the immunohistochemical expression of Bcl-2 in uterine leiomyomas in patients undergoing myomectomy or hysterectomy with and without preoperative treatment with the gonadotropin-releasing hormone receptor agonist (GnRH-a) leuprolide acetate (LA).

STUDY DESIGN

Retrospective case-control study. Seventeen patients with symptomatic uterine leiomyomata were included. Of the 17 patients, 7 were treated with LA (3.75 mg) in three monthly doses prior to myomectomy or hysterectomy. Ten patients who did not receive LA and underwent hysterectomy for leiomyomas served as controls. Formalin-fixed, paraffin-embedded archival tissue from 17 leiomyomas were immunostained with a monoclonal antibody against Bcl-2 protein. Positivity was scored semiquantitatively on a three-tier scale.

RESULTS

Immunostaining for Bcl-2 protein was intense (2-3+) in 7 LA-treated and 10 untreated leiomyomas but was scarce (0-1+) in normal myometrial smooth muscle.

CONCLUSION

Abundant expression of Bcl-2 protein may be responsible for the growth of leiomyomas by preventing apoptotic cell death. Its increased expression is maintained in GnRH-a-treated leiomyomas.

[Pharmacological stress echocardiography--a new non-invasive follow-up examination of intermittent ventilation]

BACKGROUND

Patients with chronic respiratory insufficiency frequently develop pulmonary hypertension. Non-invasive intermittent ventilation is usually very successful in these patients to improve blood gas exchange and clinical symptoms. Alterations of pulmonary hemodynamics during non-invasive intermittent ventilation are rarely described. Pharmacological stress echocardiography of the right heart is a new method to examine pulmonary hemodynamics. Aim of this study was to answer the question whether non-invasive intermittent ventilation improves pulmonary hemodynamics.

PATIENTS AND METHOD

Five patients are examined prior to and during non-invasive intermittent ventilation by right ventricular stress echocardiography at rest and during exercise. Pulmonary arterial pressure was registered and compared. The effectiveness of intermittent ventilation was evaluated with respect to blood gas analytic values.

RESULTS

During non-invasive intermittent ventilation all 5 patients improved their pulmonary arterial mean (PAP mean) and systolic pressure, but no statistical significant changes could be observed during the 4.5-months follow-up.

CONCLUSION

Non-invasive intermittent ventilation improves the pulmonary hemodynamics at rest and during exercise the results not being significant.

Segmental hyperhidrosis as a manifestation of spinal and paraspinal disease

BACKGROUND

Segmental hyperhidrosis is an uncommon finding which is usually associated with irritation or infiltration of pre-ganglionic sympathetic fibres or the sympathetic chain.

METHODS

We report two cases of segmental hyperhidrosis with striking clinical features.

RESULTS

In one case, a mesothelioma produced ipsilateral simultaneous underactivity and overactivity of sympathetic outflow and in the other case a thoracic central disc herniation was probably responsible for a band of sweating which clearly extended beyond the segmental level of injury.

CONCLUSION

Segmental hyperhidrosis should trigger a search for structural disease in the spinal and paraspinal region.

Fetal heart rate (FHR) pathology in labor related to preceeding Doppler sonographic results of the umbilical artery and fetal aorta in appropriate and small for gestational age babies. A longitudinal analysis

The aim of this study was to ascertain the value of serially performed Doppler sonographic measurements of fetal vessels for the prediction of FHR alterations in labor a longitudinal analysis was conducted. 24 patients with SGA fetuses as the only risk factor and 38 patients without any risk factor were recruited for the study. Flow velocity waveforms of the fetal aorta and the umbilical artery were analyzed for systolic diastolic (S/D) ratio weekly at 20-39 weeks gestation and from 30 weeks gestation onwards twice weekly. Courses were related to complications during labor reflected by alterations of FHR tracings. The more numerous pathologie S/D ratios of both fetal vessels were recorded the more frequently complications in labor occurred (Chi Square test, p < 0.05). The mean value of the S/D ratios in fetuses with FHR pathology in labor differed significantly compared to the uncomplicated group (Wilcoxon rank sum test, p < 0.05). The fluctuation of S/D ratios was greater in the complicated than in the normal group (Wilcoxon rank sum test, p < 0.05). A combination of parameters describing S/D ratios showed a sensitivity of 86% and a specificity of 19% for the fetal aorta and a sensitivity of 71% and a specificity of 91% for the umbilical artery. Serial Doppler measurements of the fetal aorta and the umbilical artery aid in predicting pathologic FHR alterations in labor and may be of benefit in antenatal care to ensure fetal well being particularly in cases of IUGR.

[Follow-up of intermittent self-ventilation (ISB). Mortality and causes]

BACKGROUND

Intermittent positive pressure ventilation (IPPV) has an impact on morbidity and survival in patients with chronic respiratory failure. We analyse the causes of death in relation to the disease, the age, the effectiveness of and the compliance with IPPV.

PATIENTS

The course of 108 patients, who were on IPPV for a mean of 24 (SD +/- 21) months, is analysed.

RESULTS

Twenty-seven patients die (7/7 AIS, 2/17 muscular dystrophy, 8/45 kyphoskoliosis and TB sequelae, 2/7 other neurological diseases, 6/16 COPD bronchiectasis, 1/1 fibrosis of the lang). The cause of death is in 21 hypoventilation or respiratory infection due to progressive disease (9 patients), air leakage after occlusion of tracheostoma (2 patients), bronchitis (6 patients), discontinuation of IPPV (3 patients). Two patients develop pulmonary failure (atypical mycobacteriosis and asbestosis, pulmonary embolism). Non-pulmonary causes of death are present in 2 (rupture of aortic aneurysm, pleural carcinosis).

CONCLUSIONS

A safe interface for IPPV is needed for longer survival. An efficient system of home-care has to be developed.

[Quality of life and long-term survival with intermittent self-ventilation in respiratory insufficiency caused by thoracic restrictive diseases]

BACKGROUND

Mortality and quality of life are to be assessed in patients with respiratory failure due to restrictive chest wall disease. Neither specific questionnaires, nor perspective studies are available.

PATIENTS AND METHOD

In a retrospective analysis records of mortality and morbidity, physical and social activity, and duration of IPPV are reviewed.

RESULTS

The group consists of 35 patients (mean age 56 +/- 12 years; 22 female, 13 male; 11 post tuberculosis, 24 kyphoskoliosis; IPPV duration 28.5 +/- 20.7 months). Five patients died, 3 of which during the first 4 months: In 3 death is related to respiratory symptoms, 1 is due to pulmonary embolism, 1 to disruption of aortic aneurysm. Hospitalisation is required by 12 patients in 20 instances with a mean duration of 14.2 days. Respiratory symptoms are the cause in 13 instances, special difficulties are met with occlusion of tracheostoma in 3 patients. Professional activity is performed by 14 of the 21 patients < 60 years old. Physical activity is severely reduced in 4 patients, while it is mildly to moderately compromised in 26. Seven of all patients need supplemental oxygen.

CONCLUSION

In respiratory failure due to restrictive chest wall disease treatment with IPPV seems to improve long-term survival and to enhance quality of life.

[Intermittent self-ventilation in neuromuscular diseases. Comparison of lung function parameters in ventilated and non-ventilated patients]

BACKGROUND

Based on neuromuscular-disease patients in our case, we investigate the possibility of elaborating criteria by which to judge when home intermittent mechanical ventilation should be commenced and to access its consequences over an extended period.

PATIENTS AND METHODS

Out of 24 patients with neuromuscular diseases (6 female, 18 male, mean age 32 years), 14 were treated with IPPV. They were suffering from hypercapnic respiratory failure with heavy sleep disruption and corresponding daily symptoms.

RESULTS

The aim was to calculate significant examination parameters to facilitate indication for IPPV. The clinical situation of patients dependent on respiratory support improved under IPPV. We witnessed a "ventilation-saving effect" and--despite progression of the basic disease within the monitoring period--no deterioration of the blood-gas situation.

CONCLUSIONS

It is possible to elaborate criteria for the indication of IPPV based on our group of neuromuscular-disease patients.

[Diaphragmatic paralysis and respiratory insufficiency]

BACKGROUND

Phrenic nerve palsy leads to disfunction of the main respiratory muscle. With bilateral palsy dyspnoea in the supine body position will typically occur. With one-sided lesion symptoms will only appear when a second pulmonary disease is present.

PATIENTS

We refer of 6 patients with bilateral and 5 with unilateral diaphragmatic paresis. In 3 patients neuralgic shoulder-arm-amyotrophy was diagnosed, in further 4 there was suspicion of it. Amyotrophic lateral sclerosis developed in 2 after 4 respectively 8 months. In 1 case a cervical operation led to palsy, mediastinitis in 1 case. Lung function tests showed a restrictive pattern, especially in bilateral palsy.

RESULTS

Vital capacity was reduced by almost 50% respectively 25% in the supine body position. Mouth occlusion pressure reduction was apparent. Near normal to marked hyperkapnia developed in bilateral paresis. In 5 cases non-invasive intermittent ventilation is instituted (2 volume controlled, 3 pressure supported). Two patients died (1 patient with amyotrophic lateral sclerosis after 13 months, 1 with malignant pleurisy after 4 months). Three patients continued non-invasive intermittent ventilation since 14 to 64 months.