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M Werner

Publications and source records attributed to M Werner.

At least 73 records · Page 4Linked to original sources
PubMed2001

Her-2/neu gene amplification, elevated mRNA expression, and protein overexpression in the metaplasia-dysplasia-adenocarcinoma sequence of Barrett's esophagus.

SUMMARY: The importance of alterations of the Her-2/neu oncogene in the tumorigenesis of Barrett's adenocarcinoma (BCA) is discussed controversially. In the present study, we evaluated for the first time the Her-2/neu status in the metaplasia-dysplasia-adenocarcinoma sequence of BCA simultaneously at the DNA, mRNA, and protein level using resection specimens of 25 patients. The locus-specific Her-2/neu gene status was quantified by performing fluorescence in situ hybridization, and information about the ploidy status of chromosome 17 was obtained. Tissue sections from the same areas were used for quantitative RT-PCR (TaqMan RT-PCR) of laser-microdissected tumor cells and for immunohistochemistry to quantify Her-2/neu mRNA and oncoprotein expression. Her-2/neu gene amplification was observed in 35% of BCA, and all of these samples showed strong overexpression of both mRNA and oncoprotein. A polysomy 17 without Her-2/neu gene amplification was observed in 52% of BCA, showing a normal or moderately elevated mRNA expression and no or weak immunopositivity. From 13 areas of high-grade dysplasia (HGD) we found four to be amplified for the Her-2/neu locus, whereas five showed a polysomy 17. All four samples of HGD areas with Her-2/neu gene amplification displayed mRNA and strong oncoprotein overexpression; however, lower mRNA levels were seen than in the amplified BCA areas. None of the samples with low-grade dysplasia (LGD) showed a locus-specific Her-2/neu amplification, but polysomy 17 was present in four of eight cases. No changes were detected in BCA-associated intestinal metaplasia and squamous epithelium. In summary, only a locus-specific Her-2/neu gene amplification was associated with strong mRNA overexpression and strong membranous Her-2/neu immunostaining in BCA and HGD. A chromosome 17 polysomy, as found in the majority of BCA, led to no or weak mRNA overexpression and no or weak immunopositivity. In the metaplasia-dysplasia-adenocarcinoma sequence, a chromosome 17 polysomy without Her-2/neu gene amplification was already present in LGD. This may be a result of an early polyploidization, preceding the later genetic events, such as Her-2/neu gene amplification in HGD and BCA.

Adenocarcinoma↗
PubMed2001

Biclonality of gastric lymphomas.

The pathogenesis and clonal evolution of gastric diffuse large B-cell lymphoma (DLBCL) and its relationship to extranodal marginal zone B-cell lymphoma (MZBL), mucosa-associated lymphoid tissue (MALT) type, are still controversial. The aim of this study was to establish the clonality of morphologically distinct areas of gastric lymphomas as well as their genetic relationship to each other. Six gastric lymphomas, consisting of two MZBL, MALT type, two DLBCL, and two "composite" lymphomas were subjected to laser capture microdissection and subsequent PCR-based amplification of the immunoglobulin heavy chain gene. One DLBCL showed a biclonal pattern of rearranged immunoglobulin heavy chain (IgH) genes of two different areas without evidence of a common origin. Two composite DLBCL with areas of extranodal MZBL, MALT type, were also biclonal and displayed different IgH gene rearrangements in the small-cell and in the large-cell components, respectively. Sequencing of the CDR3 region revealed unique VH-N-D and D-N-JH junctions, thus corroborating the presence of two genuinely distinct tumor clones in each of these three cases. In contrast, the remaining three gastric lymphomas (one DLBCL and two MZBL, MALT type) showed IgH gene rearrangements in which CDR3 regions were identical in the different tumor areas. Our results suggest that gastric DLBCL may be composed of more than one tumor cell clone. Further, DLBCL may not necessarily evolve by transformation of a low-grade lymphoma, but may also originate de novo. An ongoing emergence of new tumor clones may considerably hamper molecular diagnosis and follow-up of gastric DLBCL.

Base Sequence↗
PubMed2001

B"-associated factor(s) involved in RNA polymerase III preinitiation complex formation and start-site selection.

The TFIIIB transcription factor is the central component of the RNA polymerase III transcriptional machinery. In yeast, this factor is composed of three essential polypeptides TBP, TFIIIB70 and TFIIIB90, that are sufficient as recombinant proteins, together with TFIIIC, to promote accurate transcription in vitro. Here we show that a partially purified fraction, named B", that contains the TFIIIB90 subunit, displays properties distinct from recombinant TFIIIB90. This fraction contains at least a component that interacts with DNA*TFIIIC complexes, either alone or in combination with TFIIIB90, and increases the resistance of the complexes to heparin treatment. In addition, primer extension and single round transcriptions experiment reveal a different start-site selection pattern directed by B" or rTFIIIB90. In mixing experiments, we show that an activity in B", distinct from TFIIIB90, can promote transcription initiation at the +1 site without affecting the rate of preinitiation complex formation. Our data suggest the existence of at least one new component that participates in preinitiation complex formation and influences start-site selection by RNA polymerase III.

DNA-Binding Proteins↗
PubMed2001

Minimal pelvic fluid in blunt abdominal trauma in children: the significance of this sonographic finding.

PURPOSE: The aim of this study was to evaluate the significance of the ultrasonographic finding of pelvic fluid after blunt abdominal trauma in children as a predictor of an abdominal organ injury. METHODS: The clinical and imaging data of 183 children with blunt abdominal trauma were reviewed retrospectively. All children had an abdominal sonography as the primary screening study. The ultrasound results were divided into 3 groups: group A, normal examination; group B, pelvic fluid only; group C, peritoneal fluid outside the pelvis. The results of the initial ultrasound examinations were compared with the findings of the CT scan, or a second ultrasound examination or the clinical course during the hospitalization. RESULTS: Group A included 87 children; group B, 57, and group C, 39. Four abdominal organ injuries were missed by the ultrasound examination. The sensitivity and specificity of the ultrasound examinations to predict organ injury in presence of peritoneal fluid outside the pelvis were, respectively, 89.5% and 96.6%; the positive and negative predictive value were 87.2% and 97.3%. No statistically significant difference was seen between group A and group B, whereas the presence of peritoneal fluid outside the pelvic cavity (group C) was associated strongly with an organ injury (P <.001). CONCLUSIONS: A normal ultrasound examination or the presence of pelvic fluid are associated with a low probability of an organ injury. In the presence of peritoneal fluid outside the pelvis, the probability of an organ injury is very high.

Abdominal Injuries↗
PubMed2001

Chromosomal changes during development and progression of prostate adenocarcinomas.

Chromosomal copy number changes were investigated in 16 prostate carcinomas, 12 prostatic intraepithelial neoplasias (PIN; 4 low-grade and 8 high-grade) adjacent to the invasive tumour areas, and 5 regional lymph node metastases. For this purpose, comparative genomic hybridization (CGH) was performed and a copy number karyotype for each histomorphological entity was created. CGH on microdissected cells from non-neoplastic glands was carried out on 3 different cases to demonstrate the reliability of the overall procedure. None of the non-neoplastic tissue samples revealed chromosome copy number changes. In PIN areas, chromosomal imbalances were detected on chromosomes 7, 8q, Xq (gains), and on 4q, 5q, 8p, 13q and 18q (losses). In the primary tumours, recurrent (at least 25% of cases) gains on chromosomes 12q and 15q, and losses on 2q, 4q, 5q, Xq, 13q and 18q became apparent. Losses on 8p and 6q as well as gains on 8q and of chromosome 7 were also detected at lower frequencies than previously reported. The pooled CGH data from the primary carcinomas revealed a novel region of chromosomal loss on 4q which is also frequently affected in other tumour entities like oesophageal adenocarcinomas and is supposed to harbour a new tumour suppressor gene. Gains on chromosome 9q and of chromosome 16 and loss on chromosome 13q were observed as common aberrations in metastases and primary tumours. These CGH results indicate an accumulation of chromosomal imbalances during the PIN-carcinoma-metastasis sequence and an early origin of tumour-specific aberrations in PIN areas.

Adenocarcinoma↗
PubMed2001

Life-threatening gastrointestinal bleeding due to a jejunal lesion of Henoch-Schönlein purpura.

The case of a 56-year-old patient with Henoch-Schönlein purpura (HSP) and fulminant gastrointestinal bleeding is reported. The patient was admitted to hospital because of palpable purpura on both legs, painful joints and diffuse abdominal pain. Suspected HSP was histologically proven and treated with prednisolone. Despite recovery, acute gastrointestinal bleeding, with melena and a drop in hemoglobin concentration from 11.2 to 4.2 g/dl, occurred 30 days after medication was started. Immediate endoscopic examination of the upper gastrointestinal tract showed no signs of bleeding whereas colonoscopy showed fresh blood and blood clots in the terminal ileum and the colon. Since the bleeding source could not be detected endoscopically, mesenteric angiography was performed, demonstrating active bleeding from a jejunal artery. Thereafter the bleeding source was located by intraoperative peroral enteroscopy and treated by resection of a short segment of jejunum.

Gastrointestinal Hemorrhage↗
PubMed2001

Molecular diagnosis of a Mycobacterium chelonae infection.

A 23-year-old female presented with enlarged cervical lymph nodes, and a diagnosis of nonspecific lymphadenitis with formation of pyogranulomas was rendered. Despite an initial oral antibiosis and subsequent long-term intravenous and oral antibiosis under hospitalized conditions, the symptoms progressed. The lymph nodes became larger and then affected the cervical region bilaterally. Her general condition worsened, and an exanthema of the extremities accompanied by a reactive arthritis occurred. Serological assays of various viral and bacterial markers and blood cultures were negative. Application of a polymerase chain reaction (PCR) protocol allowing specific amplification of mycobacterial DNA revealed DNA of Mycobacterium chelonea in formalin-fixed, paraffin-embedded lymph node tissue. Sequencing of the PCR product showed a 97% homology with the known Mycobacterium chelonae sequence. Modification of the antibiotic therapy with clarithromycin, imipenem and amikacin resulted in a rapid regression of the symptoms. The clinical course, in combination with the difficulties in detecting the infectious agent, supports the usefulness of molecular pathological analyses specific for nontuberculous mycobacteria (NTM).

Adult↗
PubMed2001

Borrelia burgdorferi antibodies in outdoor and indoor workers in south-west Sweden.

Two hundred and fifty-three farmers and forest workers and 249 clerks from south-west Sweden were recruited to a cross-sectional seroprevalence study to find out if individuals working outdoors are more prone to acquire Borrelia burgdorferi infection than indoor workers and to find undiagnosed cases of Lyme borreliosis. The participants answered a questionnaire and blood specimens were collected to estimate the prevalence of antibodies to B. burgdorferi in each group. Sera were analysed with an enzyme-linked immunoassay technique to determine IgG antibodies to B. burgdorferi flagellum. The prevalence of B. burgdorferi antibodies was 7.6% in the farmers and forest workers vs. 5.3% in the clerks (adjusted odds ratio [age, sex] = 1.2 [95% confidence interval = 0.5-2.8]). One case of Lyme borreliosis was diagnosed. The positive predictive value of the antibody test was estimated to be 3% in the studied populations. B. burgdorferi infection is of low endemicity in south-west Sweden and is probably not an occupational risk among outdoor workers. Undiagnosed cases of Lyme borreliosis are uncommon. The test used is not acceptable for screening purposes.

Adult↗
PubMed2001

Neoadjuvant therapy of esophageal squamous cell carcinoma: response evaluation by positron emission tomography.

OBJECTIVE: To evaluate the use of positron emission tomography using [(18)F]-fluorodeoxyglucose (FDG-PET) to assess the response to neoadjuvant radiotherapy and chemotherapy in patients with locally advanced esophageal cancer. SUMMARY BACKGROUND DATA: Imaging modalities, including endoscopy, endoscopic ultrasound, computed tomography, and magnetic resonance imaging, currently used to evaluate response to neoadjuvant treatment in esophageal cancer do not reliably differentiate between responders and nonresponders. METHODS: Twenty-seven patients with histopathologically proven squamous cell carcinoma of the esophagus, located at or above the tracheal bifurcation, underwent neoadjuvant therapy consisting of external-beam radiotherapy and 5-fluorouracil as a continuous infusion. FDG-PET was performed before and 3 weeks after the end of radiotherapy and chemotherapy (before surgery). Quantitative measurements of tumor FDG uptake were correlated with histopathologic response and patient survival. RESULTS: After neoadjuvant therapy, 24 patients underwent surgery. Histopathologic evaluation revealed less than 10% viable tumor cells in 13 patients (responders) and more than 10% viable tumor cells in 11 patients (nonresponders). In responders, FDG uptake decreased by 72% +/- 11%; in nonresponders, it decreased by only 42% +/- 22%. At a threshold of 52% decrease of FDG uptake compared with baseline, sensitivity to detect response was 100%, with a corresponding specificity of 55%. The positive and negative predictive values were 72% and 100%. Nonresponders to PET scanning had a significantly worse survival after resection than responders. CONCLUSION: FDG-PET is a valuable tool for the noninvasive assessment of histopathologic tumor response after neoadjuvant radiotherapy and chemotherapy.

Adult↗
PubMed2001

From first base: the sequence of the tip of the X chromosome of Drosophila melanogaster, a comparison of two sequencing strategies.

We present the sequence of a contiguous 2.63 Mb of DNA extending from the tip of the X chromosome of Drosophila melanogaster. Within this sequence, we predict 277 protein coding genes, of which 94 had been sequenced already in the course of studying the biology of their gene products, and examples of 12 different transposable elements. We show that an interval between bands 3A2 and 3C2, believed in the 1970s to show a correlation between the number of bands on the polytene chromosomes and the 20 genes identified by conventional genetics, is predicted to contain 45 genes from its DNA sequence. We have determined the insertion sites of P-elements from 111 mutant lines, about half of which are in a position likely to affect the expression of novel predicted genes, thus representing a resource for subsequent functional genomic analysis. We compare the European Drosophila Genome Project sequence with the corresponding part of the independently assembled and annotated Joint Sequence determined through "shotgun" sequencing. Discounting differences in the distribution of known transposable elements between the strains sequenced in the two projects, we detected three major sequence differences, two of which are probably explained by errors in assembly; the origin of the third major difference is unclear. In addition there are eight sequence gaps within the Joint Sequence. At least six of these eight gaps are likely to be sites of transposable elements; the other two are complex. Of the 275 genes in common to both projects, 60% are identical within 1% of their predicted amino-acid sequence and 31% show minor differences such as in choice of translation initiation or termination codons; the remaining 9% show major differences in interpretation.

Animals↗
PubMed2001

Partners of Rpb8p, a small subunit shared by yeast RNA polymerases I, II and III.

Rpb8p, a subunit common to the three yeast RNA polymerases, is conserved among eukaryotes and absent from noneukaryotes. Defective mutants were found at an invariant GGLLM motif and at two other highly conserved amino acids. With one exception, they are clustered on the Rpb8p structure. They all impair a two-hybrid interaction with a fragment conserved in the largest subunits of RNA polymerases I (Rpa190p), II (Rpb1p), and III (Rpc160p). This fragment corresponds to the pore 1 module of the RNA polymerase II crystal structure and bears a highly conserved motif (P.I.KP.LW.GKQ) facing the GGLLM motif of Rpb8p. An RNA polymerase I mutant (rpa190-G728D) at the invariant glycyl of P.I.KP.LW.GKQ provokes a temperature-sensitive defect. Increasing the gene dosage of another common subunit, Rpb6p, suppresses this phenotype. It also suppresses a conditional growth defect observed when replacing Rpb8p by its human counterpart. Hence, Rpb6p and Rpb8p functionally interact in vivo. These two subunits are spatially separated by the pore 1 module and may also be possibly connected by the disorganized N half of Rpb6p, not included in the present structure data. Human Rpb6p is phosphorylated at its N-terminal Ser2, but an alanyl replacement at this position still complements an rpb6-Delta null allele. A two-hybrid interaction also occurs between Rpb8p and the product of orphan gene YGR089w. A ygr089-Delta null mutant has no detectable growth defect but aggravates the conditional growth defect of rpb8 mutants, suggesting that the interaction with Rpb8p may be physiologically relevant.

Amino Acid Sequence↗
PubMed2001

[Frequency of the common cold in healthy subjects during exposure to a lectin-rich and a lectin-poor mistletoe preparation in a randomized, double-blind, placebo-controlled study].

BACKGROUND/OBJECTIVE: Mistletoe preparations have immunomodulatory properties in vitro and in vivo. We wanted to investigate whether or not these properties have an effect on the frequency of the common cold in healthy subjects. PROBANDS AND METHODS: During a randomized, placebo-controlled, double-blind study 16 volunteers received the mistletoe lectin(ML)-poor preparation Iscador Pini(R) (IP), 16 the ML-rich preparation Iscador Quercus spezial(R) (IQ), and 16 placebo (physiological saline solution) twice a week subcutaneously for 12 weeks. Weekly during weeks 1-12 and finally at week 26, a careful history of common cold symptoms was taken. Because the frequency of the common cold was not the main outcome criterion in this study, the number of cases needed to treat was not adjusted to this criterion. RESULTS: The mean frequency of the common cold during the 12 weeks of injection was 1.5 in the placebo, 1.4 in the IP and 1.1 in the IQ group. During this period in 2.3 (placebo), 1.9 (IP) and 1.4 (IQ) weeks symptoms of common cold were present. The difference in favor to IQ lasted until the end of the observation period in week 26. It was, however, not significant. Leukocyte and granulocyte count as well as C-reactive protein were not different between the groups. CONCLUSIONS: The study showed a trend (p = 0.4, exact Kruskal- Wallis test) to reduced frequency and duration of the common cold in subjects who were exposed to IQ.

Adult↗
PubMed2001

Pyelocalyceal diverticulum: the imaging spectrum with emphasis on the ultrasound features.

Clinical and imaging data of 11 patients with pyelocalyceal diverticulum were retrospectively examined. Four patients suffered from ipsilateral flank pain, one from recurrent urinary tract infection and the other six from unrelated symptoms. All patients underwent ultrasound as the initial imaging study. In two cases ultrasound was the only examination performed. Additional imaging studies were obtained in the other nine patients (abdominal radiography in six cases, intravenous urography (IVU) in five and CT in four). Ultrasound suggested the diagnosis of pyelocalyceal diverticulum in eight cases owing to the presence of echogenic and mobile material within the cyst-like lesion. In three cases the ultrasound appearance was similar and indistinguishable from a simple cyst and the diagnosis was made by another imaging study IVU in two cases and CT in one). We suggest that ultrasound examination is the best imaging method for the diagnosis of a pyelocalyceal diverticulum, and no further imaging modalities are required when mobile echogenic material is seen. In uncertain cases, another relatively inexpensive imaging study should be added such as abdominal radiography or IVU.

Abdominal Pain↗
PubMed2001

Ultrasound features of spermatic cord hydrocele in children.

The aim was to evaluate the value of ultrasound diagnosis of spermatic cord hydrocele as a cause of inguinal swelling or mass in children. Clinical and ultrasound (US) findings and surgical procedures of 27 children with spermatic cord hydrocele were reviewed. All children, except one, were referred for US because of suspected inguinal hernia, hydrocele or inguinal mass. In one child, the US examination was performed to confirm the diagnosis of a spermatic cord hydrocele. An encysted hydrocele was diagnosed in 24 out of 27 cases, whereas a funicular type of spermatic cord hydrocele was found in the remaining 3 cases. Internal septa were seen within the fluid mass in four patients. 23 children underwent surgical exploration that confirmed the US diagnosis. Three children with encysted-type hydrocele were only followed clinically and by US, and one was lost from follow-up. US examination is a very sensitive and accurate method for diagnosis of this entity and for exclusion of other lesions in this region.

Adolescent↗
PubMed2001

Tumor growth inhibition in vivo and G2/M cell cycle arrest induced by antisense oligodeoxynucleotide targeting thymidylate synthase.

Chemotherapeutic agents targeting thymidylate synthase (TS) are effective against human tumors. Efficacy is limited by drug resistance, often mediated by TS overexpression. Treatment of HeLa cells in vitro with an antisense oligodeoxynucleotide (ODN 83) targeting human TS mRNA reduces TS mRNA and protein levels, inhibits cell proliferation, and sensitizes cells to TS-targeting drugs (Ferguson et al., 1999). The present study investigates the mechanism by which ODN 83 inhibits cell proliferation and examines its antitumor efficacy in vivo. ODN 83 treatment did not induce apoptosis in HeLa cells in vitro but caused accumulation of cells at G2/M. In contrast, TS-targeting chemotherapeutics arrest at G1 or S. Antisense down-regulation reduced TS mRNA levels in human colon cancer (HT29) cells by 40% in vitro, resulted in G2/M arrest, and reduced proliferation without enhanced cell death. Growth of HT29 tumors in immunocompromised mice was significantly inhibited when antisense ODN 83 treatment began promptly after tumor implantation and was accompanied by a 40% reduction in TS protein levels. Growth of tumors allowed to reach 400 mm3 prior to ODN administration was unaffected by antisense ODN 83. Radiolabeled ODNs were localized to the tumor periphery but evenly distributed in normal tissue. Thus, down-regulation of TS mRNA and protein by antisense ODN treatment exerts a novel G2/M cell cycle block without increasing cell death and inhibits HT29 tumor cell growth in vivo. Antisense ODN 83 may be an effective therapy for colon carcinoma, alone or in combination with TS-targeting cytotoxic drugs.

Animals↗