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Biomedical subjects

W Meyer

Publications and source records attributed to W Meyer.

At least 307 records · Page 17Linked to original sources
PubMed1983

Ultrasound, computed tomography and endoscopic retrograde cholangiopancreatography in the morphologic diagnosis of pancreatic disease.

From February to November 1981 the diagnostic relevance of ultrasound (US), computed tomography (CT) and endoscopic retrograde cholangiopancreatography (ERCP) was compared prospectively in 75 patients with suspected pancreatic disease. Final diagnosis was confirmed by autopsy, surgery, clinical course, and further laboratory data. Thus it was possible to exclude pancreatic disorders in 32 patients. By ERCP we diagnosed all tumors; sensitivity was 100%. Sensitivity of US and CT were 63% each. In five cases US made the false positive diagnosis" pancreatic malignant tumor" (specificity 93%), CT and ERCP in two cases (specificity 97% each). In chronic pancreatitis specificity of US and ERCP were 100% and specificity of CT was 98%. Sensitivity of ERCP amounted to 93%, CT and US revealed 74% and 52%, respectively. We conclude that ERCP is the best morphologic diagnostic tool in differentiating chronic pancreatitis from pancreatic carcinoma. US is a good screening method and CT reveals good diagnostic results in acute pancreatitis.

Adult↗
PubMed1983

Histochemistry of complex carbohydrates in the hairy skin of the domestic pig.

The hairy skin from eleven body areas of the domestic pig has been studied by means of a series of selected methods for the detection of complex carbohydrates, including peroxidase-labelled lectin-diaminobenzidine procedures. The results obtained were most distinctive in the areas where the skin accessories were involved. The complex carbohydrates in the epidermis appear to be acidic and neutral glycoproteins containing a small amount of sialic acid residues. The dermal connective tissue fibres revealed positive reactions for neutral and acidic glycoproteins with notable amounts of sialic acid residues, and for proteoglycans. In different parts of the hair follicle, neutral and acidic glycoproteins were also present, most being restricted to the connective tissue sheath and the dermal papilla. In the lower regions of the outer epithelial root sheath the epithelium contained a large amount of glycogen. The sebaceous glands reacted very weakly for neutral and acidic glycoproteins. The apocrine glands exhibited mostly neutral but also acidic glycoproteins in the secretory cells and the lumenal secretion, with substantial amounts of various saccharide residues.

Animals↗
PubMed1983

In vivo inhibition of phospholipase A2 in rat lung by an beta-adrenergic agonist.

Phospholipase A2 is the key enzyme for the release of arachidonic acid derived mediators via cycloxygenase or lipoxygenase pathways in inflammation and immunological processes. Activity of microsomal phospholipase A2 in rat lung can be inhibited by in vivo application of the beta-adrenergic drug fenoterol both in control and diseased animals.

Adrenergic beta-Agonists↗
PubMed1983

Histochemistry of complex carbohydrates in the skin of the pig snout, with special reference to eccrine glands.

The histochemistry of carbohydrates has been studied in the skin of the pig snout with selected methods of light microscopy including peroxidase-labelled lectin-diaminobenzidine (PO-LT-DAB) procedures. In the snout skin the dark secretory cells and the luminal secretion of the eccrine glands contained considerable amounts of neutral glycoproteins, but only a very small amount of acidic ones. It was possible to demonstrate glycogen in the secretory cells of these glands. The other skin structures of the snout also showed positive reactions for complex carbohydrates. Most remarkable were stronger reactions of intercellular substances among the spinosum cells, particularly following the PO-LT-DAB procedures, which demonstrated such saccharide residues as beta-D-galactose and N-acetyl-D-glucosamine.

Animals↗
PubMed1983

[Benign epithelial neoplasias of Vater's papilla].

Benign epithelial tumours of the papilla of Vater seem to be very rare. Since 1910, 75 cases have been published. 3 own cases were added. Diagnostic and therapeutic problems were discussed. Benign epithelial neoplasms of the papilla of Vater are precanceromatous. Many cases of carcinoma of the papilla may grow from benign adenomas. The treatment of choice is the local exzision of the adenoma, occasionally necessitating the reimplantation of bile and pancreatic ducts. The main problem is the treatment of adenomas with severe epithelial dysplasia. Metastatic deposits are possible but duodenopancreatectomy seems to be too aggressive an operation in such cases. In cases of severe epithelial dysplasia and focal invasion of the stroma duodenopancreatectomy should be performed. In cases of familial adenomatosis coli adenomas of the papilla should be thought of. In cases of adenomas of the papilla of Vater the colon should be examined to exclude a familial polyposis coli.

Adenoma↗
PubMed1982

Oxidative enzymes in the urinary apparatus of several marine fishes.

The distribution and activities of several oxidative enzymes in the urinary apparatus of seven marine fish species (hagfish, lesser spotted dogfish, electric ray, herring, marine catfish, cod, sea-horse) have been studied. Species were selected from three main taxonomic groups: Cyclostomata, Elasmobranchii and Teleostei. Distinctly positive enzyme reactions were found in the tubular elements of the kidney and the collecting duct-archinephric duct system, with the exception of the generally weak staining intensities for NADP-linked malate dehydrogenase. In the proximal tubule segment the second, ore distal part (PII) reacted, in general, very strongly when compared with the first proximal part (PI). If present, the distal tubule in teleosts showed only weak reactions, while this segment in elasmobranchs exhibited moderate to strong enzyme activities. In the epithelial cells of the collecting tubule-collecting duct system stronger reactions were confined to the glomerular teleost species, the corresponding part of the elasmobranch kidney showing weak staining intensities. In the urinary duct system distinctly positive enzyme reactions were only to be found in the archinephric duct of the teleost species, except for Plotosus. The ureters of the elasmobranchs exhibited weak enzymes activities throughout. The enzyme patterns of the various types of urinary tubules and ducts are compared with observations from several morphological and physiological studies. The histochemical findings are discussed in relation to corresponding investigations of freshwater fishes and problems arising from phylogenetic divergence of marine fish groups.

Animals↗
PubMed1982

A new semiautomatic method for quantitative static and dynamic bone histology.

A new semiautomatic technique combining advantages of the manual and fully automatic methods is described for obtaining quantitative static and dynamic histologic data of bone. The hardware consists of a photomicroscope, digitizing platen, digitizer, plotter/printer, floppy disc drive, and computer. The microscope is equipped with a drawing tube through which the image of the digitizing platen is projected over the optical field. The investigator selects and traces all histologic structures to be measured by moving a cursor on the digitizing platen which is visible by its projection over the histologic field. The results on accuracy and static and dynamic precision of this method show that static and dynamic parameters of bone are obtained with a degree of error (less than 20%) well within the acceptable range for biologic measurements. Comparison of this method with the grid technique according to Merz and Schenck showed that for almost all micromorphometric parameters comparable absolute data are obtained. Due to the higher precision of our method, however, the number of optical fields evaluated in obtaining these comparable data could be reduced to 25% of the number of fields evaluated by the Merz and Schenck technique. The time requirements for quantitative evaluation of a histologic slide of bone by our technique are 40-50 min; 20-25 min is needed for quantitative evaluation of osteocytes.

Bone Resorption↗
PubMed1982

Quantitative bone histology in 84 normal American subjects. Micromorphometric analysis and evaluation of variance in iliac bone.

Quantitative bone histology was done in undecalcified sections of iliac crest bone specimens obtained from 84 normal American individuals. Samples were obtained within 12 h after death in a vertical and horizontal manner from both the right and left iliac crests. In addition to the determination of normal values of micromophometric parameters of bone in these healthy American subjects, the following studies were carried out: (a) comparison of variance of micromorphometric parameters of bone obtained from the right versus left iliac bone (40 pairs), (b) comparison of micromorphometric parameters of bone obtained in a vertical versus horizontal manner (12 pairs), (c) evaluation of variance with increasing distance from the compact zone in bone samples obtained in a vertical manner (44 pairs), (d) analysis of variation between bone samples obtained more anteriorly versus posteriorly along the iliac crest (N = 40), (e) comparison of differences in micromorphometric parameters obtained from age-matched men versus premenopausal women (N = 12), and (f) plotting of histograms for assessment of distribution of micromorphometric parameters. The results show that histomorphometric data of bone cannot be easily compared when different techniques are employed for obtaining bone samples. Sampling variations are kept smaller when bone specimens are obtained in a vertical manner. Anterior/posterior variation does not cause major sampling error. If ranges of variation are taken into account, quantitative bone histology is a valuable tool for assessment of bone structure and bone cells.

Adolescent↗
PubMed1982

Phosphate depletion therapy in two ectopic calcification syndromes.

Ectopic calcification may be a complication of a wide variety of pathologic conditions. Subcutaneous calcification frequently results in restriction of motion at joints in addition to cosmetic deformity. Parenchymal tissue calcification may result in decreased organ function. Dietary phosphate restriction and total body phosphate depletion with aluminum containing antacids were used in an attempt to decrease the deposition of subcutaneous calcium phosphate which occurs with two separate syndromes. Two subjects with hyperphosphatemic tumoral calcinosis were studied by metabolic balance, by long-term clinical evaluation, and routine laboratory and radiographic techniques before and after 1 year of phosphate depletion. One patient with a newly described syndrome--normocalcemic, hypercalciuric, subcutaneous calcification--was similarly studied. The etiology of this disorder is unknown. No consistent clinically significant evidence of regression of the lesions was noted in either syndrome, although one patient with tumoral calcinosis did demonstrate some regression of his lesions. It is not clear if this response failure was due to the intrinsic nature of the diseases or to failure of patient compliance secondary to a relatively unpalatable diet.

Adolescent↗
PubMed1982

Effects of long-term infusion of physiologic doses of 1-34 PTH on bone.

It has been suggested that small doses of PTH could exert an anabolic effect on bone and could be beneficial in the management of bone diseases secondary to low bone formation. The effects of 20 wk of continuous infusion of 0.05 U.kg-1.h-1 of 1-34 PTH on cellular, structural, and dynamic parameters of bone were studied in inbred beagles. This physiologic or near physiologic dose of PTH caused a small but significant rise in the concentration of serum calcium and a significant increment in the plasma concentration of 1,25(OH)2D. In addition, the sustained infusion of PTH was associated with a significant increment in volume and surface density of osteoid without a change in bone mass. Mineralization of osteoid was not altered, as evidenced by normal double tetracycline uptake and normal osteoid seam thickness. The enhanced osteoid production was not due to augmented bone formation by individual osteoblasts or basic remodeling units but rather to increased activation frequency resulting in an increased number of remodeling units. There was also augmented bone resorption at the tissue level. The data indicate that small doses of PTH do not have an anabolic effect on the skeleton because they are not associated with increased net bone formation. Rather, PTH administration is associated with an increase in coupled bone turnover.

Animals↗
PubMed1982

Collagen fibre arrangement in the skin of the pig.

The arrangement and proportion of collagen fibres and fibre bundles in the dermis of the pig have been investigated with light microscopical (Nomarski's interference contrast, polarization optics) and scanning electron microscopical methods. Skin samples were obtained from different body regions of wild boars, domestic pigs and miniature pigs. All the methods used have demonstrated that the bulk of the dermis is dominated by a massive three dimensional network of collagen fibres and fibre bundles, which cross each other in two main directions. Several smaller fibre bundles pass through the network in various other directions, constructing a densely interwoven fibre pattern. Differences were obvious between the body regions and the animals investigated.

Animals↗
PubMed1982

Image processing in pathology. XII. Automated morphometry of tumour cell nuclei in hypernephroma: comparison between renal tumour and late metastases.

Changes of nineteen features of tumour cell nuclei in hypernephroma and three following late metastases were investigated by use of the automated image system. Histograms of nuclei features from primary tumours and metastases were compared. They showed objectively an increased cellular dedifferentiation during metastases. Various aspects of the capability of automated morphometry for investigation of tumours are discussed.

Adenocarcinoma↗