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Biomedical subjects

W Meyer

Publications and source records attributed to W Meyer.

At least 145 records · Page 8Linked to original sources
PubMed1996

'Blind' multicenter evaluation of the prognostic value of DNA image cytometric and morphometric features in invasive breast cancer.

The prognostic value of classical prognosticators in 92 invasive breast cancers with long follow-up has been compared with a number of DNA-related image cytometric features (2c deviation index (2cDI)), Auer (histogram) type, 5c exceeding rate (5cER), DNA malignancy grade (MG), and the morphometrically assessed mitotic activity index (MAI) and mean nuclear area (MNA). The quantitative analyses were carried out without knowledge of the outcome nor of clinicopathological features. The cytometric analyses and assessments of MNA were performed on Feulgen stained, 4-microns thick tissue sections in Dresden. The MAI was assessed in Amsterdam. Thereafter, the survival data were matched with the classical variables, the cytometric features, the MAI and the MNA in univariate and multivariate analyses. Lymph node status (LN) and tumour stage were significantly different, tumour stage being the strongest discriminator between survivors and non-survivors (Mantel-Cox value = MC = 30.7, P < 0.0001). Grade was (just) significant (P = 0.05). The cytometric features, the MAI and the MNA were all highly significant prognosticators. The strongest cytometric feature was the Auer type followed by the 5cER, and the 2cDI. The MNA was also significant. The MAI was the strongest single prognostic factor in this blind analysis (MC = 50.8, P < 0.0001), and the MAI combined with the lymph node status, tumour stage and the cytometric features Auer type and 2cDI was the best multivariate combination (MC = 94.0). Separate analyses of the lymph node negative (LN-, n = 39) and positive (LN+, n = 53) groups showed that the 5cER and MAI were the most important in the LN- and the MAI in the LN+ patients.

Breast Neoplasms↗
PubMed1996

[The significance of lymph- and hemangiosis carcinomatosa in colorectal carcinoma].

Between 1.1.1988 and 31.12.1989 306 patients underwent curative surgery for colorectal cancer at the surgical center of Nurnberg City hospital. The pathohistological findings showed that a carcinomatous lymphangiosis and hemangiosis (LH+) was present in 57 (18.6%) cases. The rate of metachronic metastases of the liver was significantly higher (38.2% vs. 19.6% p < 0.001) compared to patients without lymphangiosis and hemangiosis (LH-). There were also significant differences between the survival rates (5-year survival rate 50% vs. 63% p < 0.02). Analysing the lymph node stage and LH+ situation it was found that carcinomatous lymphangiosis and hemangiosis were already present in 7.2% of patients who didn't have tumorous infiltration of the lymph nodes (p NO/LH+). The 5-year survival rate was bad in both groups (54% vs. 49%).

Aged↗
PubMed1996

[Distal stenosis of the choledochus in chronic pancreatitis: endoscopic drainage or operation?].

With the less invasive techniques for complications regarding chronic pancreatitis, such as tubular choledochostenosis, the endoscopic transpapillary bile drainage therapy by means of endoprosthesis has undergone an enlargement of its indications range. Blocked and dislocated prostheses, however, further raise the already existing possibility of septic complications. With 15 out of 43 patients undergoing medium-term endodrainage treatment, we observed different resulting conditions of chronic cholestasis, such as abscess-forming cholangitis, hepatic abscesses, retroperitoneal phlegmon and sepsis up to biliary cirrhosis. Thus, in the case of chronic pancreatitis we still regard choledochostenosis- which, due to scarring, is mostly fixed-as a primary indication for operation.

Adult↗
PubMed1996

[Lymph- and haemangiosis carcinomatosa--an important prognostic factor in non-small-cell bronchial carcinoma (NSCLC)].

Between 1 Jan 1984-1 Jan 1990, 199 patients underwent curative (R0) surgery for non-small cell lung cancer. The pathohistological findings showed that a carcinomatous lymphangiosis and haemangiosis (L/H pos.) were present in 26 patients. In six patients, no lymph node metastases were detected. The median (22 mo. vs. 74 mo.) and 5-year survival (25% vs. 41%) were significantly (p < 0.001) higher compared to patients with and without lymphangiosis and haemangiosis carcinomatosa (L/H neg.). There were also significant (p < 0.05) differences in the survival time between pNO L/H neg. and pNO L/H pos. patients (median 74 mo. vs. 15 mo.-5 years 43% vs. 0%).

Capillaries↗
PubMed1995

[Psychosomatic aspects of hypertension treatment].

The outlines of doctor-patient relationship are important for the integration of non-drug therapy and drug-therapy in hypertension. Reliable cooperation between patient and physician is an important goal in treatment of hypertensive patients, which implies listening to the patient and a sufficient amount of time. This is especially important for the motivation of these hypertensives, which eventually will take psychotherapy or--and this is the larger group--look for a talk with the doctor and situational relief. An often practised part of this doctor-patient relationship is relaxation therapy.

Antihypertensive Agents↗
PubMed1995

Cataracts after bone marrow transplantation: long-term follow-up of adults treated with fractionated total body irradiation.

PURPOSE: To determine the risk of, and risk factors for, developing cataracts after bone marrow transplantation. METHODS AND MATERIALS: Four hundred and ninety-two adults who underwent bone marrow transplantation in Seattle were followed for 2 to 18 (median, 6) years. Before transplantation, patients received a preparative regimen of chemotherapy plus total body irradiation (TBI) (n = 407) or chemotherapy alone, without TBI (n = 85). TBI was administered in a single dose of 10 Gy (n = 74) or in fractionated doses totaling 12-15.75 Gy (n = 333). The risk of cataracts was determined for groups of patients with respect to the type of preparative regimen received and other pretransplant and posttransplant variables. RESULTS: One hundred and fifty-nine patients (32%) developed cataracts between 0.5 to 11 (median, 2.3) years after transplantation. The probability of cataracts at 11 years after transplantation was 85%, 50%, 34%, and 19% for patients receiving 10 Gy of single-dose TBI, > 12 Gy fractionated TBI, 12 Gy fractionated TBI, and no TBI, respectively (p < 0.0001). Among those developing cataracts, the severity was greater in patients after single-dose TBI (59% probability of surgical extraction) than after > 12 Gy fractionated TBI, 12 Gy fractionated TBI, or no TBI (33%, 22% and 23%, respectively). Patients given corticosteroids after transplant had a higher probability of cataracts (45%) than those without steroids (38%) (p < 0.0001). In a proportional hazards regression model, the variables that were correlated with an increased probability of cataracts were single-dose TBI (relative risk (RR) = 2.46) and steroid therapy (RR = 2.34), while a decreased probability of cataracts was correlated with a nonTBI preparative regimen (RR = 0.41). The yearly hazard of developing cataracts in recipients of single-dose TBI was highest during the third year after transplantation, while in recipients of fractionated TBI, the hazard was distributed among years one through seven. The probability of cataracts in all groups reached a plateau at 7 years after transplantation, after which the development of cataracts was extremely unlikely. CONCLUSION: TBI is the major risk factor for developing cataracts after BMT. Single-dose TBI results in the highest risk of cataracts. However, the risk of cataracts in recipients of fractionated-TBI is significantly higher than in patients who receive no TBI. In addition to TBI, steroid therapy is an independent risk factor for cataracts after BMT.

Adolescent↗
PubMed1995

Purification, cloning, and sequencing of archaebacterial pyrophosphatase from the extreme thermoacidophile Sulfolobus acidocaldarius.

Cytoplasmic pyrophosphatases are indispensible for the function of cellular bioenergetics. From the extreme thermoacidophilic archaeon Sulfolobus acidocaldarius, situated at one of the lowest branches of the phylogenetic tree, a cytosolic pyrophosphatase has been isolated and purified 200-fold to electrophoretic homogeneity by combining ion-exchange and gel-exclusion chromatography. The native enzyme consists of a homotetramer of 71 kDa apparent molecular mass; the subunit displays an apparent molecular mass of 17 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme has an absolute requirement for divalent cations (Mg2+) and a temperature optimum of 75 degrees C coinciding with the growth optimum of the organism; the apparent estimated activation energy is 79.5 kJ/mol. A large variety of cytosolic extracts from other archaebacteria has been probed with a polyclonal antiserum raised against the purified protein; surprisingly, except for an extremely weak signal with S. solfataricus none of the other organisms showed any cross-reactivity. Also, Escherichia coli PPase does not cross-react. Based on N-terminal sequencing the gene has been cloned and sequenced. It codes for a 173-amino-acid protein with a calculated molecular mass of 19,365 kDa. Alignment with known eucaryotic and procaryotic PPases reveals invariant conservation of all residues presently assumed to be involved in metal and substrate binding. Unexpectedly, the highest similarity is found with the enzyme from the phylogenetically extremely distant eubacterium E. coli, but immunological cross-reactivity is absent. Similarity to the only known other archaebacterial PPase is much weaker. Using the 3D structure of the Thermus thermophilus enzyme as a scaffold an energy-minimized structural model is presented, deviating only minimally from the former. The structural features are discussed. The enzyme provides an excellent model for studies of thermostability and folding dynamics since heterologous overexpression has been achieved and genetically mutated forms become accessible.

Amino Acid Sequence↗
PubMed1995

Neuron-specific enolase as a marker of hypothalamo-neurohypophyseal development in postnatal Monodelphis domestica (Marsupialia).

In the newborn Monodelphis domestica, pituitary and brain are far from their definite shape and structural organization. The presumptive neurohypophysis appears as a mass of proliferating cell immunonegative for neuron-specific enolase (NSE) in the newborn, while perikarya positive for NSE are present in the rostroventral area of the hypothalamus. At the same time, the periventricular areas of the brain, consisting of proliferating cells, are non-reactive for NSE. In the 2.5-day-old specimens of this study, the neurohypophysis displays anti-NSE reactions in the peripheral regions. In animals 8-10 days of age, the amount of reaction product in the neurohypophysis has reached highest levels. This dramatic increase parallels the increase of NSE expression in perikarya of the rostroventral and caudoventral hypothalamus as well as the formation of a band-like reaction zone between the respective hypothalamic areas and the neurohypophysis.

Animals↗
PubMed1995

Polymerase chain reaction fingerprinting in fungi using single primers specific to minisatellites and simple repetitive DNA sequences: strain variation in Cryptococcus neoformans.

Minisatellites and simple repetitive DNA sequence motifs are used as conventional oligonucleotide probes in DNA-hybridization-based fingerprinting. The same oligonucleotides can be used as single primers in the polymerase chain reaction (PCR) to generate individual PCR fingerprints. In this study, the simple repetitive sequences, (CA)8, (CT)8, (CAC)5, (GTG)5, (GACA)4 and (GATA)4, and a minisatellite core sequence derived from the wild-type phage M13 (5' GAGGGTGGCGGTTCT 3') were used as specific, single primers to amplify hypervariable repetitive DNA sequences during PCR analysis. The potential applications of this techniques are demonstrated with clinical isolates of the human pathogenic yeast, Cryptococcus neoformans. PCR fingerprint patterns have remained stable after long-term in vitro passage ( > 2 1/2 years to date). Hybridization of the primers to blots of electrophorectically separated chromosomes demonstrated that the target sequences recognized by most of the primers are dispersed through the entire yeast genome. Sequence analysis of the cloned bands obtained by PCR fingerprinting indicated that if the same or extremely similar, inversely oriented tandem repeats are located close to each other, when only one repeat-specific primer is used in the PCR, the region between these repeats is amplified. PCR fingerprinting has a wide range of current and potential applications to fungi, such as clarifying taxonomic questions, facilitating epidemiological studies and improving the diagnosis of mycotic diseases.

Base Sequence↗
PubMed1995

Prenatal development of the integument in Delphinidae (Cetacea: Odontoceti).

The prenatal development of epidermis, dermis, and hypodermis was studied in embryos of different age of two delphinid species (Stenella attenuata, Delphinus delphis), using light and transmission electron microscopical methods. The delphinid embryo is covered by a multilayered tissue formed by four different epidermal generations (periderm, stratum intermedium-I, str. intermedium-II, str. spinosum) produced by the str. basale. The first layer appears at about 40-50 mm of body length, the second type (s.i.-I) about 60-160 mm, and the third type (s.i.-II) is present at 160-500 mm. The first spinosal cells are produced at 225-260 mm body length; thenceforth, the epidermis increases continuously in thickness. Epidermal ridge formation begins about 400-mm body length. The development of the dermis is characterized by the early production of thin connective tissue fibers (40-70-mm body length) and simultaneously the cutaneous muscle matures in structure. Vascular development intensifies between embryos of 150-225 mm, and collagen production increases markedly in fetuses of 225-260-mm length. These events are paralleled by an increase in dermal thickness. The first elastic fibers can be recognized in the skin from the abdomen at about 600-mm body length. The development of the hypodermis is marked by very rapid and constantly progressing growth, beginning about 60-mm body length. The first typical fat cells appear in animals of 360-400 mm. Regional differences are obvious for all skin layers with regard to the flippers, where structural maturation proceeds more rapidly than in dorsal or abdominal regions.

Animals↗
PubMed1995

Immunohistochemical demonstration of non-muscle myosin in the developing porcine epidermis.

Using an immunohistochemical technique, the study demonstrates for the first time non-muscle myosin stress fibres in fetal mammalian epidermis, with special regard to cellular development during integumentary ontogenesis in the sparsely haired domesticated pig. The results obtained are discussed in view of possible cytoskeletal functions of the cytofilaments.

Animals↗
PubMed1995

Lectin histochemistry of snout skin and foot pads in the wolf and the domesticated dog (Mammalia: Canidae).

The distribution and selectivity of complex carbohydrates in the snout skin and the foot pads of the wolf and the domesticated dog were studied by means of light-microscopic histochemical methods, particularly lectin histochemistry. In the snout, moderate to strong staining reactions were confined to intercellular substances among the epidermal cells, containing neutral glycoconjugates (glycoproteins, glycolipids) with various saccharide residues (alpha-D-mannose, beta-N-acetyl-D-glucosamine, alpha-N-acetyl-D-galactosamine, beta-D-galactose). In the foot pads, distinct reactions were found in neutral glycoconjugates of intercellular substances of the stratum corneum, with alpha-N-acetyl-D-galactosaminyl and beta-N-acetyl-D-glucosaminyl residues, but only in the wolf, whereas in the dog such substances were concentrated in the spinosal and basal epidermal layers, additionally marked by D-galactose. The eccrine glands exhibited high amounts of mainly neutral glycoconjugates in the secretory portion, especially in the wolf. A clear spectrum of saccharide residues was demonstrable in the dark cells (alpha-D-mannose, beta-N-acetyl-D-glucosamine, alpha-N-acetyl-D-galactosamine, alpha-D-galactose), and in the clear cells which lacked mannose and contained beta-D-galactose. In contrast to the wolf, strong reactions for glycoconjugates were visible among intercellular substances of intradermal excretory duct cells in the dog. Only in the wolf did the periphery of the intracorneal excretory ducts and the outer surface of the foot pads show clearly positive reactions for glycoconjugates. The results obtained are discussed with regard to the specific functions of the body regions investigated and the behavioural biology of the Canidae. It is obvious that differences in amounts, quality, and localization of the glycoconjugates produced exist between the wolf and its domesticated descendant.

Animals↗
PubMed1995

Pentoxifylline and ciprofloxacin in patients with myelodysplastic syndrome. A phase II trial.

Tumor necrosis factor (TNF) inhibits hematopoietic cell proliferation. The combination of pentoxifylline (PTX) and ciprofloxacin (Cipro) has been previously shown to reduce circulating serum levels of TNF. In this Phase II trial 14 patients with advanced myelodysplastic syndrome were treated with PTX (2,000 mg/day) and Cipro (1,000 mg/day) in order to determine tolerability and effect on peripheral blood cell counts, progenitor cell responsiveness to cytokines and circulating serum levels of interleukin-6 (IL6) and TNF. Toxicity attributed to PTX and Cipro were limited to nausea in 4 patients. Peripheral blood cell counts, platelet transfusion requirements and red blood cell transfusion requirements did not change during administration of PTX and Cipro (daily for 28 days). Marrow progenitor cells of patients entered into trial were less responsive to stimulation with cytokines in vitro at baseline and during the trial compared to normal volunteers. Eight patients had elevated IL6 levels before treatment with PTX and Cipro these levels did not change during therapy. Five patients had elevated TNF levels at baseline. There was a suggestion of decreased TNF levels during treatment with PTX and Cipro (P = .09). In conclusion, PTX and Cipro was well tolerated but no evidence of efficacy was observed.

Adult↗
PubMed1995

Heterogeneity of the chromatin fine structure in DNA-diploid breast cancer cells.

The chromatin fine structure of Feulgen-stained DNA-diploid tumour cells was studied by means of image cytometry in fine-needle aspiration biopsies of 115 breast cancer patients. The investigation was focused on diploid, several subtypes of polyploid, and aneuploid tumours. Only the clearly separable diploid peaks of these tumours were measured cytometrically by an OPTIMAS-based image analysis system, which led to a set of 93 primary cytometric features in each diploid subpopulation. The results demonstrate that the diploid tumours are clearly different to the diploid compartments of various subtypes of polyploid and aneuploid tumours. Between those diploid subpopulations from polyploid tumours, chromatin structure differences also exist. A higher degree of similarity between polyploid and aneuploid tumours, compared to diploid, became evident. The actual structural differences between the diploid subpopulations indicate both increasing variances within the peak and increasingly coarse and contrasted, irregular chromatin structure with the occurrence of tetraploid, octoploid, and aneuploid DNA-histogram peaks. Therefore, the structural effects of an increasing genomic instability seems not to be restricted to the non-diploid cell populations.

Adenocarcinoma↗
PubMed1995

Increase of precision and accuracy of DNA cytometry by correcting diffraction and glare errors.

In recent TV-based image cytometers considerable disproportionalities exist between the IOD values of reference cells, as well as diploid, tetraploid, and octoploid analysis cells compared with their theoretical IOD ratios. An important source of these deviations is the limited spatial resolution of the microscopic objectives, based on the effects of diffraction. Compared to these influences the glare is less important. A correcting method is given for reducing both effects on the DNA measurements, which considers a narrow region along the nuclear contour to be optically disturbed. The correction of this mean optical density (MOD)- and size-dependent geometric resolution error is applicable to any cell type. The method was tested on 25 rat liver imprints and 29 fine needle aspirates from breast cancers. The resulting stemline ratios are close to the theoretical ones. A further improvement was then reached by a glare correction. The slide-by-slide variations of stemline ratios, remaining after the corrections, were considered in a test statistic for defining the aneuploidy of a given stemline. Statistically based clear-cut decision rules were obtained for DNA histogram interpretation.

Animals↗