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H Geyer

Publications and source records attributed to H Geyer.

At least 73 records · Page 4Linked to original sources
PubMed1990

Glycosylation of the envelope glycoprotein from a polytropic murine retrovirus in two different host cells.

A polytropic recombinant retrovirus containing the envelope gene of Friend mink cell focus-inducing virus plus the remainder of the genome of an amphoropic murine leukemia virus was propagated on mouse embryo fibroblasts and mink lung cells. Virus particles, metabolically labeled with [2-3H]mannose, were harvested from the culture supernatants and lysed with detergents. The viral envelope glycoprotein was isolated from the lysates by immunoaffinity chromatography and purified by preparative SDS/PAGE. Oligosaccharides were liberated by sequential treatment of tryptic glycopeptides with endo-beta-N-acetylglucosaminidase H and peptide-N4-(N-acetyl-beta-glucosaminyl) asparagine amidase F and fractionated by high-performance liquid chromatography. Individual glycans were characterized chromatographically, by methylation analyses and in part, by enzymic microsequencing. The results demonstrated that viral glycoproteins, synthesized in mouse embryo fibroblasts, carried as major constituents partially fucosylated diantennary, 2,4- and 2,6-branched triantennary and tetraantennary complex type N-glycans with 0-4 sialic acid residues and only small amounts of high-mannose type species with 5-9 mannose residues. As a characteristic feature, part of the complex type glycans contained additional Gal(alpha 1-3) substituents. Glycoprotein obtained from virions propagated on mink lung cells, contained partially fucosylated diantennary and 2,4-branched triantennary oligosaccharides with 1-3 sialic acid residues, in addition to trace amounts of high-mannose type species with 8 or 9 mannose residues. Thus, the results reveal that predominantly, the complex type N-glycans of the retroviral envelope glycoprotein display cell-specific variations including differences in oligosaccharide branching, sialylation and substitution by additional Gal(alpha 1-3) residues.

Acetylglucosaminidase↗
PubMed1990

Glycosylation of the envelope glycoprotein gp130 of simian immunodeficiency virus from sooty mangabey (Cercocebus atys).

The envelope glycoprotein 130 ('130' referring to an Mr of 130,000) of simian immunodeficiency virus from sooty mangabey (Cercocebus atys) (SIVSM) was isolated from the cell-free supernatant of the SIVSM-infected human T-cell line H9, metabolically labelled with D-[6-3H]glucosamine. After digestion with Staphylococcus aureus V8 proteinase, radiolabelled N-glycans were liberated from resulting glycopeptides by sequential treatment with endo-beta-N-acetylglucosaminidase H and peptide:N-glycosidase F and fractionated by h.p.l.c. and gel filtration. Individual oligosaccharide species were characterized by enzymic microsequencing, chromatographic analyses and, in part, by acetolysis. The oligosaccharide structures thus established include oligomannosidic glycans with five to nine mannose residues as well as fucosylated and partially sialylated bi-, tri- and tetra-antennary N-acetyl-lactosaminic oligosaccharide species, the latter of which carry, in part, additional galactose residues or N-acetyl-lactosamine repeats. In comparison with the corresponding envelope glycoprotein 120 from human immunodeficiency virus type 1 (HIV-1), propagated in the same cell line [Geyer, Holschbach, Hunsmann and Schneider (1988) J. Biol. Chem. 263, 11760-11767], carbohydrates of the simian glycoprotein were found to consist of decreased amounts of oligomannosidic glycans and increased quantities of higher-branched N-acetyl-lactosaminic species.

Animals↗
PubMed1990

Separation of glycoprotein-N-glycans by high-pH anion-exchange chromatography.

A series of high-mannose and complex type glycoprotein-N-glycans was subjected to high-pH anion-exchange chromatography. The results revealed that this method represents a useful tool for analytical characterization of single oligosaccharides as well as preparative separation of complex mixtures of carbohydrate side-chains. On the other hand, it became evident that in several cases a combination of different chromatographic techniques is required for efficient separation of individual oligosaccharide species.

Chromatography, Ion Exchange↗
PubMed1990

The oligosaccharides of influenza virus hemagglutinin expressed in insect cells by a baculovirus vector.

The hemagglutinin of fowl plague virus has been expressed in Spodoptera frugiperda (SF) cell cultures using a baculovirus vector. To elucidate the structure of the carbohydrate side chains, radioactively labeled oligosaccharides were liberated by treatment with endoglucosaminidase H and glycopeptidase F. Sequential degradation with exoglycosidases and chromatographic analyses revealed the presence of oligomannosidic side chains, predominantly of the structures Man5-9GlcNAc2, and the truncated oligosaccharide cores Man3GlcNAc2 and Man3[Fuc]GlcNAc2. Polyacrylamide gel electrophoresis of endoglycosidase-treated hemagglutinin showed that most side chains of the HA1 subunit are truncated, whereas the HA2 subunit has one oligomannosidic and one truncated oligosaccharide. Comparison of these results with the glycosylation pattern of hemagglutinin obtained from vertebrate cells allowed a tentative allocation of the oligosaccharides to individual glycosylation sites. The results indicate that SF cells have the capacity to trim N-glycans to trimannosyl cores and to further process these by the addition of fucose. Thus, the complex oligosaccharides found on hemagglutinin from vertebrate hosts are replaced on hemagglutinin derived from insect cells by small truncated side chains.

Animals↗
PubMed1990

Estrogen and progesterone receptors in endometrial cancer and their prognostic relevance.

Three hundred and nine malignant endometrial tumors were biochemically analyzed with respect to estrogen (ER) and progesterone (PR) receptors. Fifty-seven percent of endometrial carcinomas were ER and PR positive (greater than or equal to 50 fmole/mg of cytosol protein); 24% were negative for both receptors. Five sarcomas and 16 of 21 mixed müllerian tumors were receptor negative. Receptor status correlated with clinical stage and grade of histological differentiation, but not with myometrial invasion. Anamnestic data on patients showed no differences between those with receptor-negative and receptor-positive tumors. Five-year survival rate (stage I) and median survival time (stages II-IV, recurrences) for patients with ER+/PR+ and ER-/PR+ endometrial cancer were significantly better than for ER-/PR- and ER+/PR- patients. A multivariate analysis demonstrated progesterone receptor as a significant prognostic factor next to clinical stage. Estrogen receptor had no significant prognostic relevance. A retrospective analysis of gestagen treatment and progesterone receptor status confirms the importance of PR, possibly independent of hormonal treatment.

Adenocarcinoma↗
PubMed1990

[Studies on the crystallization tendency of calcium oxalate in urine--a study of experimental and computer-assisted determination of the risk of urinary calculi formation].

In this study a method o the semiquantitative determination of the crystallization tendency for calcium oxalate in urine is described. It is based on the addition of a well-defined amount of ammonium oxalate (31.3 nmol) to a urine sample (30 ml). The so caused clouding of the urine is measured by a photometer 20 min later. The method guarantees an acceptable reproducibility and is simple to be performed in each clinical laboratory. The results of mathematical correlation and discriminant analysis show that the calcium concentration influences the crystallization of calcium oxalate as most of all urinary constituents. Furthermore, evidence of a high specificity of the method is given by a reclassification rate of about 80% in the discriminant analytical computation.

Adolescent↗
PubMed1989

[SCC (squamous cell carcinoma) antigen as a tumor marker in cervix cancers].

The TA-4 antigen obtained from squamous cell carcinoma of the uterine cervix has a subunit, the SCC antigen, which can be measured in serum with a polyclonal antibody in a radioimmunoassay. SCC values less than or equal to 1.5 ng/ml were found in 96% of 48 clinically healthy women. This concentration was then set as the cut off value. Of the 122 patients with untreated squamous cell carcinoma of the cervix, 76% had SCC concentrations above 1.5 ng/ml. The CEA was raised in 50% of the cases. In stages III and IV, 89% of the SCC values was raised and 65% of the CEA. Among the 50 patients with recurrent or progressive cervical carcinoma elevated levels of SCC were found in 78% and raised CEA concentrations in 52%. Only in 25% of the cases were both tumour markers raised at the same time. Complete remission was clinically established in 48 patients with cervical carcinoma who had had increased SCC values prior to therapy. The SCC values were in the normal range in 71% of the patients, the CEA values were normal in 81%. The increase in SCC concentration often preceded the tumour recurrence by months. Up to 70% of the patients with vaginal or vulvar carcinoma had elevated SCC levels. SCC proved to be a valuable tumour marker for the follow up of cervical, vaginal, and vulvar cancer.

Adenocarcinoma↗
PubMed1989

Juvenile angiofibromas: a 40-year surgical experience.

A series of 22 patients with histologically confirmed angiofibroma were treated primarily by surgical removal at the University of Freiburg ENT clinic during the 40-year period, 1946-1986. These tumors were staged according to size and extension on the basis of roentgenographic and surgical findings. Specific analysis of the operative approaches and recurrence rate by stage are included. Recurrent or residual disease was handled by surgical excision, irradiation, embolization, or a combination of these methods. The complication and morbidity rates were extremely low, while the mortality rate was zero. The tumor specimens received from the last 5 patients were evaluated for the presence of sex hormone receptors. No specific estrogen, progesterone or androgen receptors were detected in these tissues.

Adolescent↗
PubMed1988

Carbohydrates of human immunodeficiency virus. Structures of oligosaccharides linked to the envelope glycoprotein 120.

Human T-cells (H9), persistently infected with the HTLV-III strain of human immunodeficiency virus, were metabolically labeled with D-[2-3H]mannose or D-[6-3H]glucosamine. The viral envelope glycoprotein, gp120, was isolated either from cell lysates or from cell-free culture supernatant. After proteolytic digestion, the radiolabeled oligosaccharides were sequentially liberated from glycopeptides by treatment with endo-beta-N-acetylhexosaminidase H and peptide:N-glycosidase F. Oligosaccharides released were separated from residual (glyco)peptides and fractionated according to size, charge, and fucose content. The individual oligosaccharide species obtained were characterized by digestion with exoglycosidases and by chromatographic comparison with standard oligosaccharides. Our results demonstrate that the intracellular gp120 carries predominantly oligomannosidic glycans comprising nine or eight mannose residues. The secreted glycoprotein is equally substituted by oligomannosidic species, containing seven to nine mannose residues, and by fucosylated, partially sialylated bi- and triantennary complex-type oligosaccharides.

Carbohydrate Conformation↗
PubMed1988

[Effects of sex steroids on the lipoprotein profile].

Plasma testosterone levels were measured pre- and postoperatively as well as during estrogen substitution in a 47-year-old woman with excessive hyperandrogenaemia due to a Leydig-cell tumour of the left ovary. In addition, the lipoprotein profile was determined before and 14 days after removal of the tumour and four weeks later during estrogen substitution. The preoperative plasma testosterone level was between 6.25 and 8.50 ng/ml; at the same time there was a hypercholesterolaemia with increased beta-lipoprotein and decreased alpha-lipoprotein fractions: the ratio of beta- to alpha-lipoprotein cholesterol was 3.0, a type IIa hyperlipoproteinaemia. After the testosterone concentration had returned to normal both the beta- and pre-beta cholesterol fell significantly, while the alpha-lipoprotein fraction remained unaltered. The alpha-cholesterol fraction increased significantly after estrogen substitution, the beta- to alpha-lipoprotein ratio being 1.20. It is concluded from these results that hyperandrogenaemia goes together with raised peripheral beta and pre-beta-cholesterol concentration, while estrogens cause a rise in the alpha-fraction.

Cholesterol↗
PubMed1988

[Hoof diseases as a result of stall floor defects].

The pig's hoof is characterized by sudden changes between hard and soft horn and a high growth rate of the horn wall. These facts contribute to the high incidence of hoof alterations, which is seen in various inadequate floors. Hoof alterations are only painful in cases, where the corium is irritated. Some hoof alterations are described, the question of poor footing is discussed. The author provides recommendations regarding the recognition of inadequate barn floors and their improvement. Stable claws develop in animals housed on floors with soft surfaces or under restricted movement. Hoof cracks or soft heel ulcers are frequently seen in animals housed on rough and abrasive floors. Slatted floors with wide gaps and sharp edges cause a high rate of lesions at the coronary border. The construction of slatted floors should be done with respect to the size of the hooves, which is related to the body weight. For prevention of lesions the gaps should not exceed the given values.

Animals↗
PubMed1987

[Tumor markers in gynecologic diseases].

The tumor markers CA 125, CEA, and CA 153 were measured in the serum of patients with malignant and benign gynecologic diseases. In 90% of 76 serous and endometrioid ovarian carcinomas CA 125 values were elevated (greater than 35 U/ml). In cases with primary tumors the concentrations usually exceeded 500 U/ml. CA 125 levels were also elevated in over 80% of the cases of non-epithelial ovarian malignomas and ovarian metastases. There was also in increase in markers in carcinomas not involving the ovary, as well as in benign ovarian tumors and endometrioses. Observations of the course in cases of ovarian carcinoma showed that this marker was a sensitive indicator of the clinical condition. CA 153 was found to be over the limit of 25 U/ml in 40% of 68 patients with breast cancer. The proportion of elevated values was considerably lower (28%) than in the recurrences (72%). In 72% of the cases CA 153 and CEA were correspondingly elevated or normal, while in 16% only CA 153 was elevated. The results indicate the importance of the markers, above all in aftercare of tumor cases.

Antigens, Neoplasm↗
PubMed1987

[Stimulation of ovarian function with gonadotropins following suppression of endogenous gonadotropin secretion by long-term infusion of the LHRH analog buserelin].

The treatment of infertile women by gonadotropins is more effective in hypogonadotropic than in normogonadotropic ovarian insufficiency. In order to induce a hypogonadotropic state the luteinizing hormone-releasing hormone analog (LHRHA) buserelin was administered in eight cycles of four infertile patients suffering from luteal phase defect. Buserelin was infused subcutaneously in a dosage of 400 micrograms/d for 26-44 days using a portable external osmotic minipump system. Following suppression of estradiol-17 beta below 35 pg/ml within 11 +/- 5 days, gonadotropins were injected intramuscularly to stimulate ovarian function. In all cycles treated, ovulation and formation of a functional corpus luteum were observed without signs of premature luteinization. Whereas constant administration of LHRHA by a slow release system seems very useful for long-term reversible suppression of follicular maturation, further studies should evaluate the clinical usefulness of combined LHRHA/gonadotropin treatment in cases of infertility.

Adult↗
PubMed1987

[Nuclear receptors in estrogen receptor negative tumors with progesterone receptors].

The nuclear estrogen receptors ERn were determined in 12 carcinomas whose cytoplasm contained progesterone receptors PRc but no estrogen receptors ERc. ERn were found in 9 of the tumors. Their concentration correlated to those of PRc and reached a mean of only 20% of the ERn concentrations found in ERc+/PRc + carcinomas. These results suggest that in carcinomas of the ERc-/PRc+-type, originally present cytoplasmic estrogen receptors induce the synthesis of progesterone receptors in a concentration corresponding to that of the nuclear receptors, following translocation by endogenous estradiol in the nucleus.

Breast Neoplasms↗