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Biomedical subjects

R Fischer

Publications and source records attributed to R Fischer.

At least 595 records · Page 33Linked to original sources

Laser trabeculoplasty. A prospective study of treatment variables.

Forty-five phakic eyes with open-angle glaucoma and uncontrolled intraocular pressure underwent laser trabeculoplasty. Each eye was assigned randomly to one of three treatment groups: group 1, 100 spots over 360 degrees; group 2, 50 spots over 180 degrees; or group 3, 50 spots over 360 degrees. A 50-micron spot was aimed at the anterior meshwork; power and time were varied to achieve a blanch. Forty-four eyes were followed up for at least four weeks without further intervention. The mean IOP before therapy and the initial IOP elevation were similar in all groups. After four weeks, the mean IOP reductions in 15 eyes in group 1, 15 eyes in group 2, and 14 eyes in group 3 were not significantly different. However, significantly more eyes in group 1 demonstrated a greater than 12 mm Hg reduction in IOP than eyes in the other groups. Group 2 tended to have the fewest eyes with reduced medications.

Aphakia↗

Characterization of glycoconjugates of human gastrointestinal mucosa by lectins. I. Histochemical distribution of lectin binding sites in normal alimentary tract as well as in benign and malignant gastric neoplasms.

Labeled lectins with binding specificity to the hexose components of mucus glycoproteins (HPA, RCA I, PNA, Con A, WGA, and UEA I) were used to demonstrate structural differences in the glycoprotein composition of various cell types of the normal, benign and malignant gastrointestinal mucosa. While in the RCA I, UEA I, and WGA binding of normal mucus secreting cell types only quantitative differences were observed, the mucus in the surface epithelial cells of gastric mucosa and in the colonic goblet cells was characterized by the absence of PNA, Con A, and PNA, HPA binding sites, respectively. These lectins, however, showed a strong binding to the supranuclear, Golgi-region in the undifferentiated or activated forms of these cells. Even the staining intensity of the luminal membrane surfaces of the non mucinous parietal and chief cells was often stronger by PNA, HPA, and RCA I lectins than that of the mucus secretions in the highly differentiated mucus cells. These results indicate the existence of either heterogeneous glycoprotein components or mucus molecules with variations in the degree of glycosylation of their oligosaccharide chains in the different cells. The latter seems more likely since in benign and malignant alterations lectin binding sites appear in great density, which were found to be characteristic of the undifferentiated mucus cells or for the non mucinous cells of the normal gastric mucosa. Similarly in some gastric cancers which do not stain with the periodic acid-Schiff reaction at all, large amount of free or neuraminic acid substituted PNA binding sites can be detected.

Adenocarcinoma↗

Characterization of glycoconjugates of human gastrointestinal mucosa by lectins. II. Lectin binding to the isolated glycoproteins of normal and malignant gastric mucosa.

Using affinity chromatography on HPA-, PNA-, Con A, and WGA-agarose columns only a part (10-30%) of the high molecular weight mucous glycoproteins could be isolated from the Triton X-100 solubilized components of normal as well as carcinomatous gastric mucosa. The main part of the mucus was not bound by the lectins, which corresponds to our earlier lectin histochemical observations on paraffin-embedded tissue sections. The lectin-bound mucous glycoproteins had a relatively lower molecular weight, ranging from about 250-1,000 kilodaltons, as indicated by polyacrylamide gradient gel electrophoresis and by gel filtration on Biogel A 1.5 m column. In gas chromatographic analysis the molar ratio of aminohexoses to galactose was found to be much higher (3:1) in the lectin-bound mucous substances than in the whole high molecular weight mucus (1:1). This finding indicates that lectins have a higher affinity to the hexosamine rich components of mucus, which may be special forms of mucous glycoprotein molecules or the incompletely glycosylated core and backbone regions of the oligosaccharide chains of mucus. Extremely high hexosamine values (10:1) were found in the PNA isolated mucus of gastric adenocarcinoma. Since it is known that PNA binds to the terminal disaccharide, beta-galactose-(1-3)-N-acetylgalactosamine, which is localized at the reducing end of the oligosaccharide chains of mucus, it is highly probable that the elongation of the oligosaccharide side chains is disturbed in gastric cancer cells.

Binding Sites↗

[Clinical significance of urinary tract infection caused by Providencia stuartii].

Out of 75 patients in whom nosocomial infection of the urinary tract occurred following operation for disturbance of micturition 43 (57.3%) suffered clinically manifest inflammatory complications, however only in 26 cases (34.6%) was this germ the cause. In the remaining 17 cases there were superinfections. From these results it is concluded that the isolated Providencia stuartii strains were not very virulent. In cases of asymptomatic providencia-bacteriuria the authors consider specific antibacterial therapy to be indicated only if the excretion of germs does not cease spontaneously after micturition has been restored to normal.

Adult↗

Treatment of chronic active hepatitis--present state.

Nowadays, both Anglo-Saxon and Middle European pathologists define chronic active hepatitis as synonymous with chronic aggressive hepatitis (CAH) without cirrhotic transformation. For its treatment, an accurate determination of the histological stage is necessary. CAH with slight to moderate activity (type 2a) requires merely general treatment, while corticosteroids and/or immunosuppressives are contraindicated. The latter drugs are indicated only for HBs- and HBeAG-negative CAH of type 2b with marked inflammatory activity. Every case should, however, be carefully assessed to determine whether these drugs might not be contraindicated. Our own experience with more than 600 patients with CAH shows that the prognosis is most favourable in HBs- and HBeAg-negative patients, in whom pre-existing chronic infections have been quickly recognized and eradicated, and in whom corticosteroids and/or immunosuppressives were not required. In the meantime, 13% of the CAH patients without cirrhotic transformation have been cured, and 42.5% improved. In contrast, CAH treatment with interferon, Virazol, arabinoside and immunostimulation remain disappointing.

Biopsy, Needle↗

Stereospecificity of phenylalanine plasma kinetics and hydroxylation in man following oral application of a stable isotope-labelled pseudo-racemic mixture of L- and D-phenylalanine.

L-[15N]Phenylalanine and D-[2H5]phenylalanine have been administered orally to two healthy adult volunteers as a pseudo-racemic mixture at a dose of 25 mg/kg each. After oral application, the plasma kinetics of phenylalanine and tyrosine have been followed by the combined use of high pressure liquid chromatography and field desorption mass spectrometry. Additional incubation with D-amino acid oxidase was used to determine the enantiomeric composition of the differently labelled species of phenylalanine and tyrosine. D-Phenylalanine plasma levels show a faster rise to higher maximum values compared to L-phenylalanine (D/L ratio at maximum 3.19, 3.26). L-Phenylalanine is efficiently hydroxylated to L-tyrosine. In contrast, conversion of D-phenylalanine to the L-form with subsequent hydroxylation to L-tyrosine was observed. From the plasma kinetics it is estimated that about 1/3 of the applied dose of 25 mg/kg of D-phenylalanine is converted to the L-isomer. Of the administered dose of L-phenylalanine only very small amounts are excreted into urine as such (0.25%, 0.8%), whereas a substantial amount of the D-phenylalanine dose is found in urine (27.4%, 38.0%).

Adult↗

[Results of the palliative treatment of inoperable squamous cell carcinoma of the esophagus].

From 1961 to 1981, 132 patients suffering from squamous cell carcinoma of the oesophagus were seen at the Bad-Cannstadt-Municipal-Hospital. In 53 cases only a palliative procedure could be performed: 20 patients had tube intubation, 29 gastrostomy, only 4 an exploratory laparotomy. The mortality rate of palliative operations is a high one, postoperative complications are frequent, the mean postoperative survival time is about 4.3 months. As the method of choice, preference is given to tube intubation, gastrostomy should be no longer performed with the exception of a few special cases.

Carcinoma, Squamous Cell↗

Histochemical tumor markers for evaluation of hormone dependence in breast cancer.

Lectin from the peanut (peanut agglutinin = PNA) possesses a high affinity for D-galactosyl-(1-3)-N-acetyl-D-galactosamine, used for histochemical investigations on formalin-fixed tissue sections of normal mammary gland as well as of benign and malignant breast diseases. Thereby, a lectin-binding pattern was found that partly exhibited secretory malfunction. Additional studies with a labeled antibody directed against a milk fat globule membrane glycoprotein, which was isolated by PNA affinity chromatography from human milk, confirmed the PNA receptor as a marker of a milk protein in breast carcinomas. The most important clinicopathological finding, however, was that in accordance with the secretory activity about 77% of PNA-positive tumors responded to endocrine treatment, whereas PNA-negative mammary carcinomas usually failed to show any response to hormonal therapy. These results also correlated with the hormone receptor content of tumor tissue.

Breast Neoplasms↗