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W Meyer

Publications and source records attributed to W Meyer.

At least 73 records · Page 4Linked to original sources
PubMed2000

Pathomorphological and histological prognostic factors in curatively resected ductal adenocarcinoma of the pancreas.

The fate of patients with potentially resectable carcinomas is not only determined by the pTNM tumor stage, but also possibly by tumor-biological factors. The aim of this study was to identify these prognostic factors in patients undergoing primary curative (R0) resection. The study retrospectively analyzed 113 patients with ductal adenocarcinoma who were operated on between 1986 and 1995. R0 resection was able to be performed in 93 patients. Lymph node metastases were found in 73%. The rates of lymph vessel and perineural invasion were 83.5% and 45%, respectively. Among the 25 carcinomas without lymph node metastases, 64% already had lymph vessel invasion and 48% had perineural invasion. The cumulative 5-year survival rate of the 91 surviving patients analyzed was 10.5%. Depending on the tumor stage we found a significant difference in 5-year survival rates between patients without lymph node metastases (26.5%) and those with lymph node involvement (5%) (P = 0.008). A multivariate analysis only identified lymph vessel invasion (L0/1), tumor size (< or = or < or =2 cm), and tumor grading (G) to have significant and independent prognostic value. Lymph vessel invasion, tumor size, and tumor grading proved to be independent factors determining long-term prognosis.

Adenocarcinoma↗
PubMed2000

Competence on demand in DNA image cytometry.

Quantitation methods in clinical pathology have to be normalized and standardized both from the instrumental and the methodological point of view to guarantee a defined level of precision and accuracy independent of the site where they are applied. The comparability of results obtained in different laboratories is the basis for the application of standardized diagnostic classification systems and therapeutic schemes. Remote quantitation based on standardized evaluation tools could be a way to reach the goals mentioned above. Diagnostic DNA image cytometry, increasingly used as a routine method in clinical pathology, will serve as an example for demonstrating the feasibility and usefulness of a concept of remote quantitation. We report a system for a remote DNA ploidy analysis, based on client server technology, and accessible via Internet or ISDN connections (Quantitation Server EUROQUANT). This system (i) allows the cytometric measurement of the DNA content of cells for diagnostic purposes, (ii) provides the user with comprehensive quality control of such measurements, (iii) helps in trouble-shooting, and (iv) gives assistance in diagnostic interpretation. The system uses the principles of telepathology and Internet technology. To date, more than 40 laboratories from Europe, USA, and Asia have successfully performed analyses on about 3,000 ploidy data sets.

Confidentiality↗
PubMed2000

Lectin histochemistry of the canine anal glands.

The distribution and selectivity of complex carbohydrates in the canine anal glands were studied by means of lectin histochemistry, using PO-labeled lectins. The secretory epithelium of the anal glands and the excretory duct system exhibited large amounts of mainly neutral glycoproteins with various terminal sugars (alpha-D-mannose, beta-N-acetyl-D-glucosamine, alpha-N-acetyl-D-galactosamine, alpha-D-galactose, alpha-L-fucose, N-acetyl-neuraminic acid). Distinctly prominent in the secretion were alpha-L-fucose residues. This relatively hydrophobic sugar may in particular modify or control the viscoelastic properties of the anal gland mucus, so that a stable mucous coat of the rather dry faeces can be formed. In addition, it was obvious that the major part of the excretory duct system is also involved in secretion production, and that the essential function of the saccular dilatations of the excretory ducts is to ensure secretion maturation.

Acetylgalactosamine↗
PubMed2000

[Is resection of left-sided ductal pancreatic carcinoma of value?]].

UNLABELLED: The ductal adenocarcinoma of the left part of the pancreas is concerned to be incurable. With the aid of the own patient material and the data from the literature an analysis was made to find out whether this negative prognostic assessment can be accepted. METHODS: The findings of 60 patients with tumors in the corpus/cauda region of the pancreas served as a basis for the investigation (observation time: 1986-1998). The resected tumors were reclassified according to the UICC from 1997. The survival rates were calculated with the method of Kaplan-Meier. RESULTS: Only 12 (20%) of the 60 tumors were resectable, in 6 cases only by multivisceral resection. A R0-resection was possible in 8 cases. 11 of these 12 patients had already a lymph vessel invasion (L1) and 50% an involvement of lymph nodes (pN1). After curative resection the median survival time was 17 months, after palliative resection 4 months and in cases with inoperability only 3.6 months. The survival time is identical with the results after operative treatment of carcinomas of the pancreatic head. CONCLUSIONS: Stage related the prognosis of the left sided pancreatic carcinoma is comparable with the results after similar therapy of the pancreatic head carcinoma. Therefore therapeutic nihilism is not indicated.

Adenocarcinoma↗
PubMed2000

Routine DNA cytometry of benign and malignant pleural effusions by means of the remote quantitation server Euroquant: a prospective study.

AIM: To analyse the practicability and potential assistance of static DNA cytometry performed by means of the remote quantitation server Euroquant and the internet in routine diagnostic analysis of pleural effusions, and to outline the role of DNA cytometry on pleural effusions in distinguishing between benign and malignant (and herein primary versus metastatic) effusions. MATERIALS AND METHODS: Cytological smears of 294 pleural effusions were stained with the Feulgen method. The DNA content of a minimum of 300 randomly chosen analysis nuclei and 30 reference nuclei (lymphocytes) was measured by internet connection to the remote quantitation server Euroquant. Cytometric features were derived from the histograms, and the time needed for case evaluation, the reliability of staining and measurement procedures, and the contribution to the final diagnosis were evaluated. RESULTS: Only 120 of 294 pleural effusions could be measured. The total measurement time for each specimen was 60 minutes. The guidelines of the consensus report on DNA measurements were fulfilled. Seventy eight malignant (18 mesotheliomas, 60 metastatic tumours) and 42 benign effusions were measured. Seven of 78 malignant effusions were euploid and none of 42 benign effusions were aneuploid. The sensitivity and specificity were 91% and 100%, respectively, for distinguishing benign from malignant effusions, and 95% and 100%, respectively, for discriminating between benign and malignant effusions caused by metastatic malignant tumours. CONCLUSIONS: Static DNA cytometry using the remote quantitation server Euroquant can be performed reliably in the routine diagnosis of pleural effusions; however, only 40% of effusions meet the technical requirements for static DNA cytometry. Within the measurable cases, static DNA cytometry made an important contribution to the confirmation/exclusion of malignancy.

Aged↗
PubMed2000

DNA ploidy and chromosomal imbalances in invasive ductal breast cancer. A comparative study of DNA image cytometry and comparative genomic hybridization (CGH).

Chromosomal imbalances were analyzed in 62 breast cancers with different DNA ploidy by CGH. The results of DNA image cytometry and CGH are consistent with peridiploid and aneuploid cases. The peritetraploid tumors harbored a high number of chromosomal imbalances, as a hint for an unfavorable prognosis. The quantitative analysis of imbalances highlighted the role of different physical constituents of the chromosome, and of chromosomal losses in different DNA ploidy groups. The peritetraploid and aneuploid tumors differed from the peridiploid tumors in losses at 8p and 18q. The peritetraploid cancers exhibited more gains at 8q, the aneuploid tumors more losses at 17p than their peridiploid counterparts. The aneuploid cases differed from the peritetraploid tumors in a higher number of losses at 11q and 14q. Combinations of imbalances provide further insights into the genetic background of DNA ploidy. Hypotheses for the progression from peridiploid to nondiploid breast cancers are given.

Breast Neoplasms↗
PubMed2000

A telepathology based Virtual Reference and Certification Centre for DNA image cytometry.

An increasing need for flexible consultation between pathologists, including the application of fast evolving supplementary technologies, has been identified during the last years. Although pathology is already one of the most advanced application of telemedicine there is more to come from the fast evolution towards computerized microscope image analysis: A reproducible quantification of measurable descriptors of the lesions in cells and tissues (so-called biological markers) is an indispensable adjunct to routine diagnostic application. Among such quantitative methods DNA image cytometry is increasingly applied by pathologists for assistance in diagnostics. As for other pathological issues, too, a reference center for the clinical application of DNA image cytometry might be therefore of utmost value for pathologists using that method. Based on advanced telematic technologies, a Virtual Reference and Certification Center (VRCC) could be installed for certifying the cytometry hardware and software, the analytical procedures, and the basic interpretation of the results. It will be designed to be operated as a non-attended service, based on quantification servers accessible via Internet round the clock. The VRCC will supply appropriate standardization and normalization materials and run a GroupWare platform for consensus making by experts.

Certification↗
PubMed2000

Telepathology: design of a modular system.

Although telepathology systems have been developed for more than a decade, they are still not a widespread tool for routine diagnostic applications. Lacking interoperability, software that is not satisfying user needs as well as high costs have been identified as reasons. In this paper we would like to demonstrate that with a clear separation of the tasks required for a telepathology application, telepathology systems can be built in a modular way, where many modules can be implemented using standard software components. With such a modular design, systems can be easily adapted to changing user needs and new technological developments and it is easier to integrate modular systems into existing environments.

Computer Systems↗
PubMed2000

Fluorescence polarization immunoassay for the detection of drugs of abuse in human whole blood.

Fluorescence polarization immunoassay (FPIA) is a technique which has been known for a number of years. Since the development of the fundamental principles of fluorescence polarization by Perrin in a series of papers beginning in 1926, immunological techniques using labelled reactants have gained an extraordinary importance in the field of medical research and in routine diagnosis. As one of the non-radioactive immunological techniques, FPIA has found broad application in clinical and forensic toxicology. The authors report a new method to quickly screen autopsy, police and hospital blood samples for opiates, benzodiazepines, benzoylecgonine, barbiturates and methadone after Extrelut extraction utilising the FPIA methodology.

Anti-Anxiety Agents↗
PubMed2000

Prognostic role of K-ras in patients with progressive colon cancer who received treatment with Marimastat (BB2516).

We determined the prognostic role of K-ras mutation in tumor tissue of patients with refractory colon cancer who received Marimastat (BB2516). DNA was extracted from paraffin-stored tumor tissue of 27 patients who previously failed 5-fluorouracil and were treated with BB2516. The presence of K-ras mutation was characterized by Polymerase Chain Reaction using ras- and p53-specific primers. ras and p53 oncoprotein expression was analyzed by an automated biotin-avidin immunoproxidase technique. Seventeen patients had a normal K-ras sequence and 10 patients had a K-ras mutation. Median survival of patients with a normal ras sequence was 330 days from the time of BB2516 treatment compared with 160 days for patients with a K-ras mutation (p = 0.0442, Wilcoxon; 0.0130 Log-Rank). No differences in age, sex, cancer stage, surgical treatment, or chemotherapy treatment were observed. Abnormalities involving ras expression did not affect survival. By comparison, median survival for patients with p53 mutation or p53 overexpression was both 158 days after BB2516 treatment. Patients having both K-ras and p53 mutations had the poorest median survival of 113 days (p = 0.035). There is a suggestion by univariate analysis that the presence of a K-ras mutation may predict survival in patients with progressive colon cancer. Further assessment with larger patient numbers and multivariate analysis is indicated.

Adult↗
PubMed2000

SEM demonstration of elastic fibres in the integument of small and densely-haired mammals.

The combination of SEM and autoclave methods gave a clear three-dimensional demonstration of integumental elastic fibres in small densely-haired mammals. The specific organisation of a fine and spongy elastic network was characterised by uniformly thin elastic fibres which were homogeneously distributed between both hair follicle types throughout the whole dermis. All the hair follicles were connected with each other by elastic fibres along their complete intradermal length. The advantage of such a specific elastic dermis construction is that all hair follicles can be moved together and simultaneously along the entire body, so that a better and rapid insulation is achieved after erection of the hair follicles during very low temperatures.

Animals↗
PubMed2000

Epidemiology: surveillance of fungal infections.

Surveillance for fungal diseases is essential to improve our understanding of their epidemiology and to enable research and prevention efforts to be prioritized. In order to conduct better surveillance for fungal diseases, it is important to develop more accurate and timely diagnostic tests, to follow rigorous epidemiological methods and to have adequate support from public health agencies and the pharmaceutical industry. Investigations of nosocomial and community outbreaks of fungal infection have also resulted in a better understanding of the sources and routes of transmission of these diseases, and of the risk factors for infection. This has led to more effective prevention and control strategies. In addition, outbreak investigations have offered excellent opportunities to develop new molecular sub-typing methods, and to evaluate and validate older ones. For example, results obtained from a global epidemiological study of the genomic structure of Cryptococcus neoformans have led to a better understanding of the epidemiology of cryptococcosis. Similarly, a study of variations in the genotype of Trichophyton rubrum has found that patients may become infected with multiple strains, which has important implications for study design when looking at the epidemiology of dermatophyte infections.

Arthrodermataceae↗
PubMed1999

The relative value of CD4 cell count and quantitative HIV-1 RNA in predicting survival in HIV-1-infected women: results of the women's interagency HIV study.

OBJECTIVES: To determine factors associated with survival and to assess the relative strength of CD4 cell count and HIV-1 RNA in predicting survival in a cohort of HIV-1-infected women. DESIGN: Prospective cohort, enrolled during 1994-1995, with median follow-up of 29 months RESULTS: Of 1769 HIV-infected women 252 died. In multivariate analyses, lower CD4 cell count, higher quantitative plasma HIV-1 RNA, and the presence of a self-reported AIDS-defining (Class C) condition were significantly associated with shorter survival: the relative hazard (RH) of dying was 1.17, 3.27, and 8.46, respectively for women with baseline CD4 cell count of 200-349, 50-199, and < 50 x 10(6) cells/l, compared with women with CD4 cell count of > or = 350 x 10(6) cells/l. Compared with women with HIV-1 RNA levels of < 4000 copies/ml plasma, the RH of dying for women with baseline quantitative HIV-1 RNA measurements of 4000-20,000, 20,000-100,000, 100,000-500,000 and > 500,000 copies/ml, was 2.19, 2.17, 3.16, and 7.25, respectively. CD4 cell count had as strong a prognostic value as HIV-1 RNA level, particularly among participants with more advanced immunodeficiency. When the analysis was adjusted to eliminate the distortion created by having disproportionately sized strata of the categorized variables, the relative hazard of death associated with CD4 cell count became even larger in comparison with that for HIV-1 RNA. Eliminating from the analysis all follow-up time during which participants could have received highly active antiretroviral therapy did not change these findings. Age was not a predictor of survival after adjustment for covariates. CONCLUSIONS: CD4 cell count and HIV-1 RNA had similar prognostic value in this cohort of HIV-1-infected women. Even in the presence of a low viral burden, a substantially decreased CD4 cell count remained a strong predictor of mortality.

CD4 Lymphocyte Count↗
PubMed1999

Phase I trial of interferon gamma retroviral vector administered intratumorally with multiple courses in patients with metastatic melanoma.

The purpose of this study was to determine the safety and antitumor activity of IFN-gamma retroviral vector in patients with advanced melanoma. Seventeen patients (9 single courses, 8 multiple courses) received a total of 363 intratumor injections of IFN-gamma retroviral vector (1 x 10(7) PFU/ml administered at 0.3, 0.5, and 1.0 ml per cohort). No grade III/IV adverse events were attributed to study medication. Replication-competent retrovirus was not detected in any of the 17 patients by polymerase chain reaction studies. Eight patients showed elevated anti-tumor antibody responses in comparison with baseline by ELISA. One of nine patients treated with a single course had an optimal response of stable disease, compared with eight of eight multiple-injected patients. Median survival of single-injected patients was 150 days, and patients who received multiple injections have still not achieved median survival duration, with four of eight still living (p = 0.0462, Wilcoxon; p = 0.0273, log rank). We conclude that intratumor injection of IFN-gamma is safe and well tolerated. Evidence of antitumor activity is suggested in patients with advanced malignancy that received multiple injections.

Adult↗
PubMed1999

Molecular typing of global isolates of Cryptococcus neoformans var. neoformans by polymerase chain reaction fingerprinting and randomly amplified polymorphic DNA-a pilot study to standardize techniques on which to base a detailed epidemiological survey.

A total of 356 clinical isolates of the encapsulated basidiomycetous fungus Cryptococcus neoformans var. neoformans, obtained from Australia, Argentina, Brazil, India, Italy, New Zealand, Papua New Guinea, South Africa, Thailand and the USA, were analyzed to lay the basis for a comprehensive evaluation of the global genetic structure of C. neoformans. Two polymerase chain reaction (PCR)-based typing techniques were standardized: PCR fingerprinting using a single primer specific to minisatellite or microsatellite DNA, and randomly amplified polymorphic DNA (RAPD) analysis using two combinations of three 20- to 22-mer random primers. Previous studies showed that the resultant profiles are reproducible and stable over time. Identical results were obtained in two different laboratories and by different scientists in the same laboratory. Both typing techniques separated the isolates into four major groups (VNI and VNII, serotype A; VNIII, serotype A/D; and VNIV, serotype D). The majority (78%) of isolates belonged to VNI, compared with 18% VNII, 1% VNIII and 3% VNIV. All US isolates could be differentiated by a unique, strain-specific PCR fingerprint or RAPD pattern in contrast to most of the non-US isolates, which showed a substantially higher degree of genetic homogeneity, with some clonality, in different parts of the world. Isolates obtained from the same patient at different times and from different body sites, had identical banding patterns. Both typing techniques should provide powerful tools for epidemiological studies of medically important fungi.

Base Sequence↗
PubMed1999

[Comparative analysis of various standard immunohistochemical procedures].

Immunohistochemical staining techniques, such as the APAAP, ABC, EnVision and Immuf1p4x methods, play a leading role in the search to solve the questions arising in clinical diagnosis. With the increase in number of techniques for diagnostic examination, the sarch for suitable method is becoming more and more important. The goal of this study was to compare these different treatments with regard to sensitivity and specificity. Furthermore, an analysis of time and cost was made. The primary antibodies used were CD20, CD30 and IgM, as well as receptor antibodies estrogen and progesterone. The variable costs of each technique were calculated based on selected examples. The APAAP method required the most time and was, at the same time, by far the most expensive treatment. The EnVision method required the least time and showed very good staining results, which were comparable to those of the ABC and ImmunoMax techniques. The staining costs could be reduced by about 95% and the staining intensity improved substantially by using expensive receptor antibodies in combination with the Immuno-Max method. This study illustrates the importance of knowing different examination techniques, as well as the costs arising by their usage.

Antigens, CD20↗
PubMed1999

[Restrictive dermopathy].

Restrictive dermopathy is a rare, fatal, autosomal recessive, congenital skin disease. Rigidity of translucent thin skin, which is thus highly vulnerable and tears, spontaneously causes intra-uterine fetal akinesia or hypokinesia deformation sequence (FADS), characteristic dysmorphic facies with fixed open mouth in O position, and generalized joint contractures (arthrogryposis). Polyhydramnios and pulmonary hypoplasia are distinctive manifestations, leading to respiratory insufficiency and premature delivery at about 31 weeks of gestation. We report on a case of a prematurely born infant who presented with the typical morphological features and describe the light- and electron-microscopical findings as described in the literature.

Abnormalities, Multiple↗